EWADC21T-SSB3 - Air-conditioner DAIKIN - Free user manual and instructions

USER MANUAL EWADC21T-SSB3 DAIKIN

Air cooled chiller with screw compressor MICROTECH CONTROLLER

Contents

1 Introduction......5
2 Controller Features....6
3 General Description....7

3.1 General Description 7

3.2 Control Panel Layout 7

3.3 Hardware Structure 7

3.4 System Architecture....8

3.4.1 Control network details....9

4 Sequence of Operation 10
5 Controller Operation....13

5.1 MicroTech Inputs/Outputs 13

5.1.1 Analog Inputs 13

5.1.2 Analog Outputs....13

5.1.3 Digital Inputs....13

5.1.4 Digital Outputs 13

5.2 Extension I/O Compressor #1 to #3....14

5.2.1 Analog Inputs 14

5.2.2 Analog Outputs....14

5.2.3 Digital Inputs....14

5.2.4 Digital Outputs 14

5.3 I/O EXV Circuit #1 to #3 14

5.3.1 Analog Inputs 14

5.3.2 Analog Outputs....14

5.3.3 Digital Inputs....14

5.3.4 Digital Outputs 14

5.4 Extension I/O Fan Module Circuit #1 & 2....15

5.4.1 Digital Inputs.... 15

5.4.2 Digital Outputs....15

5.5 Extension I/O Fan Module Circuit #3 15

5.5.1 Digital Outputs 15

5.6 Extension I/O Unit Alarm & Limiting....15

5.6.1 Analog Inputs 15

5.6.2 Analog Outputs....15

5.6.3 Digital Inputs....15

5.6.4 Digital Outputs....15

5.7 Setpoints 16

5.7.1 Auto Adjusted Ranges 19

5.7.2 Dynamic Default Values....19

6 Unit Functions....20

6.1 Calculations....20

6.1.1 LWT Slope 20

6.1.2 Pulldown Rate 20

6.2 Unit Type....20

6.3 Unit Enable....20

6.4 Unit Mode Selection....20

6.4.1 Glycol Configuration 21

6.5 Unit Control States 21

6.6 Unit Status....22

6.7 Ice Mode Start Delay 22

6.8 Evaporator Pump Control 22

6.8.1 Pump Selection 22

6.8.2 Primary/Standby Pump Staging 23

6.8.3 Auto Control 23

6.9 Noise Reduction....23

6.10 Leaving Water Temperature (LWT) Reset 23

6.10.1 LWT Target 23

6.10.2 Leaving Water Temperature (LWT) Reset 23

6.10.3 4-20 mA External Signal Reset 24

6.10.4 Outside Air Temperature (OAT) Reset 24

6.11 Unit Capacity Control 25

6.11.1 Compressor Staging in Cool Mode 25

6.11.2 Compressor Staging in Ice Mode 25

6.11.3 Staging Sequence 25

6.11.4 Compressor Capacity Control In Cool Mode 26

6.11.5 Load/Unload Sequence 26

6.11.6 Compressor Capacity Control In Ice Mode 26

6.12 Unit Capacity Overrides 26

6.12.1 Soft Load 26

6.12.2 Demand Limit 26

6.12.3 Network Limit 27

6.12.4 Current Limit 27

6.12.5 Maximum LWT Pulldown Rate 27

6.12.6 High Water Temperature Capacity Limit 27

6.13 Daikin on Site 27

6.14 Heat Recovery 27

6.15 Heat Recovery Pump 28

6.16 Rapid Restart 28

7 Software Options 30

7.1 Inserting the Password in a Spare Controller 30

7.1.1 Modbus MSTP Software Option....31

7.1.2 BACNET MSTP 32

7.1.3 BACNET IP 33

8 Circuit Functions 34

8.1 Calculations....34

8.1.1 Refrigerant Saturated Temperature 34

8.1.2 Evaporator Approach 34

8.1.3 Suction Superheat....34

8.1.4 Discharge Superheat....34

8.1.5 Oil Differential Pressure 34

8.1.6 Maximum Saturated Condenser Temperature....34

8.1.7 High Saturated Condenser – Hold Value 34

8.1.8 High Saturated Condenser – Unload Value 34

8.1.9 Condenser Saturated Temperature Target 34

8.1.10 Heat Recovery Condenser Saturated Temperature Target 34

8.2 Circuit Control Logic 34

8.2.1 Circuit Availability 34

8.2.2 Starting 34

8.3 Circuit Status.... 35

8.4 Compressor Control 36

8.5 Condenser Fan Control 37

8.5.1 Saturated Condenser Temperature Target 37

8.5.2 Heat Recovery Saturated Condenser Temperature Target 37

8.6 EXV Control (for chiller units) 38

8.7 Economizer Control 39

8.8 Subcooler Control 39

8.9 Liquid Injection 39

9 Alarms and Events 40

9.1 Signaling Alarms 40

9.2 Clearing Alarms 40

9.2.1 Remote Alarm Signal 40

9.3 Description of Alarms....40

9.3.1 Phase Volts Loss/GFP Fault 40

9.3.2 Evaporator Flow Loss 40

9.3.3 Evaporator Water Freeze Protect 40

9.3.4 Evaporator #1 Water Freeze Protect 41

9.3.5 Evaporator #2 Water Freeze Protect 41

9.3.6 Evaporator Water Temperatures Inverted 41

9.3.7 Leaving Evaporator Water Temperature Sensor Fault 41

9.3.8 Leaving Evaporator Water Temperature Sensor Fault #1 41

9.3.9 Leaving Evaporator Water Temperature Sensor Fault #2 41

9.3.10 AC Comm Failure 41

9.3.11 Outdoor Air Temperature Sensor Fault 41

9.3.12 External Alarm....41

9.3.13 Emergency Stop Alarm 41

9.4 Unit Events....41

9.4.1 Entering Evaporator Water Temperature Sensor Fault 42

9.4.2 Unit Power Restore 42

9.4.3 External Event 42

9.4.4 Low Ambient Lockout 42

9.5 Option Alarms 42

9.5.1 Heat Recovery Water Freeze Protect 42

9.5.2 Heat Recovery Leaving Water Temperature Sensor Fault 42

9.5.3 Option Comm Failure 42

9.6 Option Events....42

9.6.1 Heat Recovery Entering Water Temperature Sensor Fault 42

9.6.2 Low Heat Recovery Entering Water Temperature Lockout 42

9.7 Circuit Stop Alarms 42

9.7.1 Phase Volts Loss/GFP Fault 43

9.7.2 Low Evaporator Pressure 43

9.7.3 Low Pressure Start Fail 43

9.7.4 Mechanical Low Pressure Switch 43

9.7.5 High Condenser Pressure 43

9.7.6 Low Pressure Ratio 43

9.7.7 Mechanical High Pressure Switch....43

9.7.8 High Discharge Temperature 43

9.7.9 High Oil Pressure Difference 43

9.7.10 Oil Level Switch 43

9.7.11 Compressor Starter Fault 44

9.7.12 High Motor Temperature 44

9.7.13 Low OAT Restart Fault 44

9.7.14 No Pressure Change After Start 44

9.7.15 No Pressure At Startup 44

9.7.16 CC Comm Failure N 44

9.7.17 FC Comm Failure Circuit 1/2 44

9.7.18 FC Comm Failure Circuit 3....44

9.7.19 FC Comm Failure Circuit 4....44

9.7.20 FC Comm Failure Circuit 3/4 45

9.7.21 EEXV Comm Failure N 45

9.7.22 Evaporator Pressure Sensor Fault 45

9.7.23 Condenser Pressure Sensor Fault 45

9.7.24 Oil Pressure Sensor Fault 45

9.7.25 Suction Temperature Sensor Fault 45

9.7.26 Discharge Temperature Sensor Fault 45

9.7.27 Motor Temperature Sensor Fault 45

9.8 Circuit Events 45

9.8.1 Low Evaporator Pressure - Hold 45

9.8.2 Low Evaporator Pressure - Unload 46

9.8.3 High Condenser Pressure - Hold 46

9.8.4 High Condenser Pressure - Unload 46

9.8.5 Failed Pumpdown 46

9.8.6 Power Loss While Running 46

9.9 Alarm Logging 46

10 Using the Controller 47

10.1 The Unit Controller Operation 47

10.2 Navigating 48

10.2.1 Passwords....48
10.2.2 Navigation Mode 48
10.2.3 Edit Mode 49

11 Optional Remote User Interface 54

11.1 Embedded Web Interface 55

12 Start-up and Shutdown 57

12.1.1 Seasonal Start-up....57

13 Basic Control System Diagnostic 58

14 Controller maintenance....60

15 Freecooling control (if available) 61

15.1 Freecooling Priority 61
15.2 Condensing Priority 61

List of figures

Figure 1, Control Panel Components 7
Figure 2, Hardware structure....7
Figure 3, System Architecture 8
Figure 4, Unit Sequence of Operation (see Figure 9 for circuit sequence of operation) ...... 10
Figure 5, Circuit Sequence of Operation....12
Figure 6, Unit Controller 47
Figure 7, Typical Screen 47
Figure 8, Password Menu 48
Figure 9, Password Entry Page....48
Figure 10, Home Page, Main Menu Parameters and Links 50
Figure 11, Navigation, Part A 51
Figure 12, Navigation, Part B 52
Figure 13, Navigation, Part C....53

1 Introduction

This manual provides setup, operating, troubleshooting and maintenance information for the DAIKIN Air Cooled Chillers with screw compressor (no VFD) with 1, 2 and 3 circuits using Microtech Controller.

⚠️ DANGER

Dangers indicate a hazardous situation which will result in death or serious injury if not avoided.

! WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe personal injury, or death if not avoided.

! CAUTION

Cautions indicate potentially hazardous situations, which can result in personal injury or equipment damage if not avoided.

! WARNING

Electric shock hazard: can cause personal injury or equipment damage. This equipment must be properly grounded. Connections to, and service of, the Microtech control panel must be performed only by personnel who are knowledgeable in the operation of this equipment.

CAUTION

Static sensitive components. A static discharge while handling electronic circuit boards can cause damage to the components. Discharge any static electrical charge by touching the bare metal inside the control panel before performing any service work. Never unplug any cables, circuit board terminal blocks, or power plugs while power is applied to the panel.

NOTICE

This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with this instruction manual, can cause interference to radio communications. Operation of this equipment in a residential area can cause harmful interference, in which case the user will be required to correct the interference at the user's own expense. Daikin disclaims any liability resulting from any interference or for the correction thereof.

Readout of the following temperature and pressure readings:

• Entering and leaving chilled water temperature
• Saturated evaporator refrigerant temperature and pressure
• Saturated condenser refrigerant temperature and pressure
  • Outside air temperature
• Suction line, and discharge line temperatures – calculated superheat for discharge and suction lines
• Oil pressure

Automatic control of primary and standby chilled water pumps. The control will start one of the pumps (based on lowest run-hours) when the unit is enabled to run (not necessarily running on a call for cooling) and when the water temperature reaches a point of freeze possibility.

Two levels of security protection against unauthorized changing of setpoints and other control parameters.

Warning and fault diagnostics to inform operators of warning and fault conditions in plain language. All events and alarms are time and date-stamped for identification of when the fault condition occurred. In addition, the operating conditions that existed just prior to an alarm shutdown can be recalled to aid in isolating the cause of the problem.

Twenty-five previous alarms and related operating conditions are available.

Remote input signals for chilled water reset, demand limiting, and unit enable.

Test mode allows the service technician to manually control the controllers' outputs and can be useful for system checkout. Building Automation System (BAS) communication capability via LonTalk®, Modbus®, or BACnet® standard protocols for all BAS manufacturers.

Pressure transducers for direct reading of system pressures. Preemptive control of low evaporator pressure conditions and high discharge temperature and pressure to take corrective action prior to a fault trip.

The control panel is located on the front of the unit at the compressor end. There are three doors. The control panel is behind to left-hand door. The power panel is behind the middle and right-hand doors.

3.1 General Description

The Microtech control system consists of a microprocessor-based controller and a number of extension modules, which vary depending on the unit size and conformation. The control system provides the monitoring and control functions required for the controlled, efficient operation of the chiller.

The operator can monitor all critical operating conditions by using the screen located on the main controller. In addition to providing all normal operating controls, the Microtech control system will take corrective action if the chiller is operating outside of its normal design conditions. If a fault condition develops, the controller will shut a compressor, or the entire unit, down and activate an alarm output.

The system is password protected and only allows access by authorized personnel. Except that some basic information is viewable and alarms can be cleared without a password. No settings can be changed.

3.2 Control Panel Layout

Figure 1, Control Panel Components

120V Aux Fuses Emergency Stop Relay Control Circuit Breaker Microtech Control Board Alarm Control Board Fan Expansion Module Unit On/Off switch #1 Compressor On/Off Switch #2 Compressor On/Off Switch Terminal Blocks

NOTES: The Emergency Switch Relay de-energizes circuit #1 #2 and #3 control power when activated, causing an immediate compressor and fan shutdown. The red emergency button switch is located on the bottom front of the control panel door. The control power transformer is located in the power panel adjacent to the control panel. Additional extension (aka extension) modules are located elsewhere on the chiller.

3.3 Hardware Structure

The Microtech control system for air cooled screw chillers consists of a main unit controller with a number of extension I/O modules attached depending on the chiller size and configuration.

Up to two optional BAS communication modules may be included on request. An optional Remote Operator Interface panel may be included, connected with up to nine units. The Advanced Microtech controllers used on air cooled screw chillers are not interchangeable with previous MicroTech II controllers.

Figure 2, Hardware structure

graph TD
    A["MicroTech Unit Controller"] --> B["Communication Cards"]
    A --> C["External IO Modules"]
    D["Remote Operator Interface"] --> E["20.60"]
    F["Network"] --> A
    G["Network"] --> A
    H["Network"] --> A
    I["Network"] --> A
    J["Network"] --> A
    K["Network"] --> A
    L["Network"] --> A
    M["Network"] --> A
    N["Network"] --> A
    O["Network"] --> A
    P["Network"] --> A
    Q["Network"] --> A
    R["Network"] --> A
    S["Network"] --> A
    T["Network"] --> A
    U["Network"] --> A
    V["Network"] --> A
    W["Network"] --> A
    X["Network"] --> A
    Y["Network"] --> A
    Z["Network"] --> A

3.4 System Architecture

The overall controls architecture uses the following:

• One Microtech main controller
- I/O extension modules as needed depending on the configuration of the unit
- Optional BAS interface as selected

Figure 3, System Architecture

graph TD
    A["BAS Interface (Bacnet,Lon,Mod bus)"] --> B["Microtech III Main Controller"]
    B --> C["Peripheral Bus"]
    C --> D["I/O Extension Cool/Heat Switch"]
    D --> E["I/O Extension Fans Circuit 2"]
    E --> F["I/O Extension Fans Circuit 3"]
    F --> G["I/O extension Compressor 1"]
    G --> H["I/O extension EXV 1"]
    H --> I["I/O extension Compressor 2"]
    I --> J["I/O extension EXV 2"]
    J --> K["I/O extension Compressor 3"]
    K --> L["I/O extension EXV 3"]
    L --> C

3.4.1 Control network details

Peripheral Bus is used to connect I/O extensions to the main controller.

Controller/Extension Module	Address	Usage
Unit	n/a	Used on all configurations
Compressor #1	2	Used on all configurations
EEXV #1	3
Comp. #2	4
EEXV #2	5
Alarm/Limit	18	Used on all configurations
Fans #1&2	6	Used when number of fans on circuit 1 is more than 6, number of fans on circuit 2 is more than 6, or unit has multipoint power
Comp. #3	7	Used when configured for 3
EEXV #3	8
Fans#3	9
Comp. #4	10	Used when configured for 4 circuits
EEXV #4	11
Fans #4	12
Fans #3&4	13	Used when number of fans on circuit 3 or 4 is more than 6
Options	19	Used for Heat Recovery

Communication modules

Any of the following modules can be connected directly to the left side of the main controller to allow a BAS interface to function.

Module	Usage
BacNet/IP	Optional
Lon	Optional
Modbus	Optional
BACnet/MSTP	Optional

Figure 4, Unit Sequence of Operation (see Figure 9 for circuit sequence of operation)

graph TD
    A["Unit power up"] --> B["Unit in Off state"]
    B --> C{Is unit enabled?}
    C -->|No| B
    C -->|Yes| D{Is low ambient lockout active?}
    D -->|No| E["Evaporator pump output on"]
    D -->|Yes| F{Is flow present?}
    F -->|No| E
    F -->|Yes| G["Wait for chilled water loop to recirculate"]
    G --> H["Keep pump output on while chiller is enabled and either running or ready to run"]
    H --> I{Is there enough load to start chiller?}
    I -->|No| E
    I -->|Yes| J["End"]

AWS Chiller Sequence of Operation in Cool Mode

The chiller may be disabled via the unit switch, the remote switch, the keypad enable setting, or the BAS network. In addition, the chiller will be disabled if all circuits are disabled, or if there is a unit alarm. If the chiller is disabled, the unit status display will reflect this and also show why it is disabled.

If the unit switch is off, the unit status will be Off:Unit Switch. If the chiller is disabled due to network command, the unit status will be Off:BAS Disable. When the remote switch is open, the unit status will be Off:Remote Switch. When a unit alarm is active, the unit status will be Off:Unit Alarm. In cases where no circuits are enabled, the unit status will be Off:All Cir Disabled. If the unit is disabled via the Chiller Enable set point, the unit status will be Off:Keypad Disable.

Low ambient lockout will prevent the chiller from starting even if it is otherwise enabled. When this lockout is active, the unit status will be Off:Low OAT Lock.

If the chiller is enabled, then the unit will be in the Auto state and the evaporator water pump output will be activated.

The chiller will then wait for the flow switch to close, during which time the unit status will be Auto:Wait for flow.

After establishing flow, the chiller will wait some time to allow the chilled water loop to recirculate for an accurate reading of the leaving water temperature. The unit status during this time is Auto:Evap Recirc.

The chiller is now ready to start if enough load is present. If the LWT is not higher than the Active Setpoint plus the Start Up Delta T, the unit status will be Auto:Wait for load.

If the LWT is higher than the Active Setpoint plus the Start Up Delta T, the unit status will be Auto. A circuit can start at this time.

graph TD
    A["Start first circuit."] --> B["Load/unload as needed to satisfy load."]
    B --> C{Is more capacity needed to satisfy load?}
    C -->|No| B
    C -->|Yes| D{Has the stage up time delay expired?}
    D -->|No| B
    D -->|Yes| E["* Start next circuit."]
    E --> F["Load/unload as needed to satisfy load."]
    F --> G{Can less circuits handle the load?}
    G -->|No| F
    G -->|Yes| H["Sh* down one circuit."]
    H --> I["End"]

The first circuit to start is generally the available circuit with the least number of starts. This circuit will go through its start sequence at this point.

The first circuit will be loaded and unloaded as needed in an attempt to satisfy the load by controlling LWT to the Active Setpoint.

If a single circuit is not enough to satisfy the load, additional circuits will need to be started. An additional circuit will be started when all running compressors are loaded to a specific capacity and the LWT is higher than the Active Setpoint plus the Stage Up Delta T.

A minimum time must pass between the starting of circuits. The time remaining can be viewed on the HMI if the minimum password level is active.

The second circuit will go through its start sequence at this point.

Note that a third circuit can be started if available. The two preceding conditions must again be satisfied after starting the second circuit before starting the third circuit.

All running circuits will now be loaded/unloaded as needed to satisfy the load. When possible, they will load balance so that running circuits are providing nearly equal capacity.

As the load drops off, the circuits will unload accordingly. If the LWT drops below the Active Setpoint minus the Stage Down Delta T, one circuit will shut off. If all running circuits are unloaded below a minimum value, this can also result in one circuit shutting off.

A minimum time must pass between the shutting down of circuits. The time remaining can be viewed on the HMI if the minimum password level is active.

The next circuit to shut off is generally the one with the most run hours.

Figure 5, Circuit Sequence of Operation

graph TD
    A["Unit power up"] --> B["Circuit is in Off state"]
    B --> C{Is circuit is enabled to start?}
    C -->|No| B
    C -->|Yes| D{Are compressor cycle timers active?}
    D -->|No| E{Is compressor oil sump ready?}
    E -->|No| D
    D -->|Yes| F["Circuit is ready to start"]
    F --> G{Is circuit commanded to start?}
    G -->|No| F
    G -->|Yes| H["Run circuit"]
    H --> I{Is circuit commanded to shut down?}
    I -->|No| F
    I -->|Yes| J["Pumpdown circuit"]

AWS Sequence of Operation - Circuits

When the circuit is in the Off state the EXV is closed, compressor is off, and all fans are off.

The circuit must be enabled before it can run. It may be disabled for several reasons. When the circuit switch is off, the status will be Off:Circuit Switch. If the BAS has disabled the circuit, the status will be Off:BAS Disable. If the circuit has an active stop alarm then the status will be Off:Cir Alarm. If the circuit has been disabled via the circuit mode set point, the status will be Off:Cir Mode Disable.

A minimum time must pass between the previous start and stop of a compressor and the next start. If this time has not passed, a cycle timer will be active and the circuit status will be Off:Cycle Timer.

If the compressor is not ready due to refrigerant in the oil, the circuit cannot start. The circuit status will be Off:Refr In Oil.

If the compressor is ready to start when needed, the circuit status will be Off:Ready.

When the circuit begins to run, the compressor will be started and the EXV, fans, and other devices will be controlled as needed. The normal circuit status at this time will be Run.

When the circuit is commanded to shut down, a normal shut down of the circuit will be performed. The circuit status during this time will be Run:Pumpdown. After the shut down is completed, the circuit status will normally be Off:Cycle Timer initially.

5.1 MicroTech Inputs/Outputs

I/O for the unit control and for circuits one and two are found on CP1. The chiller may be equipped with one to three compressors.

5.1.1 Analog Inputs

#	Description	Signal Source	Expected Range
AI1	Evaporator Entering Water Temp	NTC Thermister (10K@25°C)	-50°C – 120°C
AI2	Evaporator Leaving Water Temp	NTC Thermister (10K@25°C)	-50°C – 120°C
AI3	Evaporator #1 Leaving Water Temp (*)	NTC Thermister (10K@25°C)	-50°C – 120°C
X1	Evaporator #2 Leaving Water Temp (*)	NTC Thermister (10K@25°C)	-50°C – 120°C
X2	Outside Ambient Temperature	NTC Thermister (10K@25°C)	-50°C – 120°C
X4	LWT Reset	4-20 mA Current	1 to 23 mA

5.1.2 Analog Outputs

#	Description	Output Signal	Range
X5	Fan VFD #1	0-10VDC	0 to 100% (1000 steps resolution)
X6	Fan VFD #2	0-10VDC	0 to 100% (1000 steps resolution)
X7	Fan VFD #3	0-10VDC	0 to 100% (1000 steps resolution)
X8	Fan VFD #4	0-10VDC	0 to 100% (1000 steps resolution)

5.1.3 Digital Inputs

#	Description	Signal Off	Signal On
DI1	Unit PVM	Fault	No Fault
DI2	Evaporator Flow Switch	No Flow	Flow
DI3	Double Set Point/ Mode Switch	Cool mode	Ice mode
DI4	Remote Switch	Remote off	Remote on
DI5	Unit Switch	Unit off	Unit on
DI6	Emergency Stop	Unit off/rapid stop	Unit on

5.1.4 Digital Outputs

#	Description	Output OFF	Output ON
DO1	Evaporator Water Pump	Pump Off	Pump On
DO2	Unit Alarm	Alarm not Active	Alarm Active (Flashing= circuit alarm)
DO3	Circuit #1 Fan Step #1	Fan Off	Fan On
DO4	Circuit #1 Fan Step #2	Fan Off	Fan On
DO5	Circuit #1 Fan Step #3	Fan Off	Fan On
DO6	Circuit #1 Fan Step #4	Fan Off	Fan On
DO7	Circuit #2 Fan Step #1	Fan Off	Fan On
DO8	Circuit #2 Fan Step #2	Fan Off	Fan On
DO9	Circuit #2 Fan Step #3	Fan Off	Fan On
DO10	Circuit #2 Fan Step #4	Fan Off	Fan On

5.2 Extension I/O Compressor #1 to #3

5.2.1 Analog Inputs

#	Description	Signal Source	Expected Range
X1	Discharge Temperature	NTC Thermister (10K@25°C)	-50°C – 120°C
X2	Evaporator Pressure	Ratiometric (0,5-4,5 Vdc)	0 to 5 Vdc
X3	Oil Pressure	Ratiometric (0,5-4,5 Vdc)	0 to 5 Vdc
X4	Condenser Pressure	Ratiometric (0,5-4,5 Vdc)	0 to 5 Vdc
X7	Motor Protection	PTC Thermistor	n/a

5.2.2 Analog Outputs

#	Description	Output Signal	Range
Not Needed

5.2.3 Digital Inputs

#	Description	Signal Off	Signal On
X6	Starter Fault	Fault	No fault
DI1	High Pressure Switch	Fault	No fault

5.2.4 Digital Outputs

5.2.4.1 E:U. Configuration

#	Description	Output Off	Output On
DO1	Start Compressor	Compressor Off	Compressor On
DO2	Economizer	Solenoid Closed	Solenoid Open
DO3	Non-modulating Slide Load	Solenoid Closed	Solenoid Open
DO4	Liquid Injection	Solenoid Closed	Solenoid Open
DO5	Modulating Slide Load	Solenoid Closed	Solenoid Open
DO6	Modulating Slide Unload	Solenoid Closed	Solenoid Open
X5	Modulating Slide ‘Turbo’	Solenoid Closed	Solenoid Open
X8	Spare

5.3 I/O EXV Circuit #1 to #3

5.3.1 Analog Inputs

#	Description	Signal Source	Expected Range
X2	Suction Temperature	NTC Thermister 10K@25°C)	-50°C – 120°C

5.3.2 Analog Outputs

#	Description	Output Signal	Range
Not Needed

5.3.3 Digital Inputs

#	Description	Signal Off	Signal On
DI1	Low Pressure switch (optional)	Fault	No fault (optional)

5.3.4 Digital Outputs

#	Description	Output Off	Output On
DO1	Liquid Line (optional)	Solenoid Closed	Solenoid Open (optional)

Stepper Motor Output

#	Description
M1+	EXV Stepper Coil 1
M1-
M2+	EXV Stepper Coil 2
M2-

5.4 Extension I/O Fan Module Circuit #1 & 2

5.4.1 Digital Inputs

#	Description	Output Off	Output On
DI1	PVM/GFP Circuit #1	Fault	No fault
DI2	PVM/GFP Circuit #2	Fault	No fault

5.4.2 Digital Outputs

#	Description	Output Off	Output On
DO1	Circuit #1 Fan Step #5	Fan Off	Fan On
DO2	Circuit #1 Fan Step #6	Fan Off	Fan On
DO3	Circuit #2 Fan Step #5	Fan Off	Fan On
DO4	Circuit #2 Fan Step #6	Fan Off	Fan On

5.5 Extension I/O Fan Module Circuit #3

5.5.1 Digital Outputs

#	Description	Output Off	Output On
DO1	Circuit #3 Fan Step #5	Fan Off	Fan On
DO2	Circuit #3 Fan Step #6	Fan Off	Fan On

5.6 Extension I/O Unit Alarm & Limiting

5.6.1 Analog Inputs

#	Description	Signal Source	Expected Range
X1	Heat Recovery Entering Water Temperature	NTC Thermister 10K@25°C)	-50°C – 120°C
X2	Heat Recovery Leaving Water Temperature	NTC Thermister 10K@25°C)	-50°C – 120°C

5.6.2 Analog Outputs

#	Description	Output Signal	Range
Not Needed

5.6.3 Digital Inputs

#	Description	Signal Off	Signal On
X3	Heat Recovery Mode Enable	Heat Recovery Off	Heat Recovery On

5.6.4 Digital Outputs

#	Description	Output Off	Output On
DO1	Heat Recovery Pump	Pump Off	Pump On
DO2	Sub cooler #1	Sub cooler Off	Sub cooler On
DO3	Sub cooler #2	Sub cooler Off	Sub cooler On
DO4	Sub cooler #3	Sub cooler Off	Sub cooler On
DO5	Sub cooler #4	Sub cooler Off	Sub cooler On

5.7 Setpoints

The following parameters are remembered during power off, are factory set to the Default value, and can be adjusted to any value in the Range column.

Read and write access to these set points is determined by the Global HMI (Human Machine Interface) Standard Specification.

Table 1, Setpoint Value and Range

Description	Default		Range
Unit	Ft/Lb	SI
Manufacturing Location	Not Selected		Not Selected, Europe, USA
Unit Enable	OFF		OFF, ON
Unit Type	Chiller		MCU, Chiller
Unit Status after Power Failure	OFF		OFF, ON
Control source	Local		Local, Network
Available Modes	Cool		COOLCOOL/w GLYCOLCOOL/ICE w GLYCOLICETEST
Cool LWT 1	44 °F	7 °C	See section 5.7.1
Cool LWT 2	44 °F	7 °C	See section 5.7.1
Heat Recovery LWT		45 °C	30 to 60 °C
Ice LWT	25 °F	-4 °C	20 to 38°F / -8 to 4 °C
Startup Delta T	5 °F	2,7 °C	0 to 10 °F / 0 to 5 °C
Shut Down Delta T	2.7 °F	1.5 °C	0 to 3 °F / 0 to 1,7 °C
Stage Up Delta T (between compressors)	2 °F	1 °C	0 to 3 °F / 0 to 1,7 °C
Stage Down Delta T (between compressors)	1 °F	0,5 °C	0 to 3 °F / 0 to 1,7 °C
Heat Recovery Differential		3.0 °C	/2 to 5 °C
Max Pulldown	3 °F/min	1,7 °C/min	0.5-5.0 °F /min / 0,3 to 2,7 °C/min
Evap Recirc Timer	30		0 to 300 seconds
Evap Control	#1 Only		#1 Only, #2 Only, Auto,#1 Primary, #2 Primary
LWT Reset Type	NONE		NONE, RETURN, 4-20mA, OAT
Max Reset	10 °F	5 °C	0 to 20 °F / 0 to 10 °C
Start Reset Delta T	10 °F	5 °C	0 to 20 °F / 0 to 10 °C
Start Reset OAT	75 °F	23.8 °C	50°F – 85°F / 10.0 – 29.4°C
Max Reset OAT	60 °F	15.5 °C	50°F – 85°F / 10.0 – 29.4°C
Soft Load	Off		Off, On
Begin Capacity Limit	40%		20-100%
Soft Load Ramp	20 min		1-60 minutes
Demand Limit	Off		Off, On
Current Limit	Off		Off, On
Current @ 20mA	800 Amp		0 to 2000 Amp = 4 to 20 mA
Current limit Set Point	800 Amp		0 to 2000 Amp
# of Circuits	2		2-3-4
Ice Time Delay	12		1-23 hours

Continued next page.

Description	Default		Range
Unit	Ft/Lb	SI
Clear Ice Timer	No		No,Yes
SSS Communication	No		No, Yes
PVM	Multi Point		Single Point, Multi Point, None(SSS)
Noise Reduction	Disabled		Disabled, Enabled
Noise Reduction Start Time	21:00		18:00 – 23:59
Noise Reduction End Time	6:00		5:00 – 9:59
Noise Reduction Condenser Offset	10.0 °F	5 °C	0.0 to 25.0 °F
BAS Protocol	None		None, BACnet, LonWorks, Modbus
Ident number	1		0-?????
Baud Rate	19200		1200,2400,4800,9600,19200
Evap LWT sensor offset	0 °F	0 °C	-5.0 to 5.0 °C / -9.0 to 9.0 °F
Evap EWT sensor offset	0 °F	0 °C	-5.0 to 5.0 °C / -9.0 to 9.0 °F
OAT sensor offset	0 °F	0 °C	-5.0 to 5.0 °C / -9.0 to 9.0 °F
Compressors-Global	Ft/Lb	SI
Start-start timer	20 min		15-60 minutes
Stop-start timer	5 min		3-20 minutes
Pumpdown Pressure	14,3 PSI	100 kPa	10 to 40 PSI / 70 to 280 kPa
Pumpdown Time Limit	120 sec		0 to 180 sec
Light Load Stg Dn Point	50%		20 to 50%
Load Stg Up Point	50%		50 to 100%
Stage Up Delay	5 min		0 to 60 min
Stage Down Delay	3 min		3 to 30 min
Stage Delay Clear	No		No, Yes
Max # Comps Running	4		1-4
Sequence # Cir 1	1		1-4
Sequence # Cir 2	1		1-4
Sequence # Cir 3	1		1-4
Number of Pulses 10% to 50%	10		10 to 20
Slide Load Delay Minimum	30 seconds		10 to 60 seconds
Slide Load Delay Maximum	150 seconds		60 to 300 seconds
Slide Unload Delay Minimum	10 seconds		5 to 20 seconds
Slide Unload Delay Maximum	50 seconds		30 to 75 seconds
Liquid Injection Activation	185 °F	85 °C	75 to 90 °C
Liquid Line Solenoid Valves	No		No, Yes
Alarm Limits
Low Evap Pressure-Unload	23.2 PSI	160 kPa	See section 5.7.1
Low Evap Pressure-Hold	27.5 PSI	190 kPa	See section 5.7.1
Oil Press Delay	30 sec		10-180 sec

Description	Default		Range
Unit	Ft/Lb	SI
Oil Press Differential	35 PSI	250 kPa	0-60 PSI / 0 to 415 kPa
Low Oil Level Delay	120 sec		10 to 180 sec
High Discharge Temperat.	230 °F	110 °C	150 to 230 °F / 65 to 110 °C
High Lift Pressure Delay	5 sec		0 to 30 sec
Low Pressure Ratio Delay	90 sec		30-300 sec
Start Time Limit	60 sec		20 to 180 sec
Evaporator Water Freeze	36 °F	2,2 °C	See section 5.7.1
Evaporator Flow Proof	15 sec		5 to 15 sec
Recirculate Timeout	3 min		1 to 10 min
Low Ambient Lockout Enable	Disable		Disable, Enable
Low Ambient Lockout	55 °F	12 °C	See section 5.7.1

The following set points exist individually for each circuit:

Description	Default		Range	PW
	Ft/Lb	SI
Circuit mode	Enable		Disable, enable, test	S
Compressor Size	To be Verified			M
Heat Recovery Enable	Disable		Disable, enable	S
Economizer	Enable		Disable, enable	M
Capacity Control	Auto		Auto, Manual	S
Manual Capacity	See note 1 below table		0 to 100%	S
Clear Cycle Timers	No		No, yes	M
EXV control	Auto		Auto, manual	S
EXV position	See note 2 below table		0% to 100%	S
EXV model	Danfoss ETS250		ETS50, ETS100, ETS250, ETS400, E2VA, E2VP, E4V, E6V, E7V, SER, SEI25, Sex50-250, CUSTOM	S
Oil Sump Check	Enable		Enable, Disable	S
Service Pumpdown	No		No, Yes	S
Evap pressure offset	0PSI	0kPa	-14.5 to 14.5 PSI /-100 to 100 kPa	S
Cond pressure offset	0PSI	0kPa	-14.5 to 14.5 PSI /-100 to 100 kPa	S
Oil pressure offset	0PSI	0kPa	-14.5 to 14.5 PSI /-100 to 100 kPa	S
Suction temp offset	0°F	0°C	-5.0 to 5.0 deg	S
Discharge temp offset	0°F	0°C	-5.0 to 5.0 deg	S
Fans
Fan VFD enable	On		Off, On	M
Number of fans	5		5 to 12	M
Saturated Condenser Temp Target Min	90 °F	32°C	80.0-110.0 °F / 26.0 to 43.0 °C	M
Saturated Condenser Temp Target Max	110 °F	43°C	90.0-120.0 °F / 32.0 to 50 °C	M
Heat Recovery Saturated Condenser Temp Target Min		50°C	/ 44 to 58 °C	M
Heat Recovery Saturated Condenser Temp Target Max		56°C	/ 44 to 58 °C	M
Fan Stage Up Deadband 0	5 °F	2.5 °C	1-20 °F / 1-10 °C	M
Fan Stage Up Deadband 1	5 °F	2.5 °C	1-20 °F / 1-10 °C	M
Fan Stage Up Deadband 2	8 °F	4 °C	1-20 °F / 1-10 °C	M
Fan Stage Up Deadband 3	10 °F	5 °C	1-20 °F / 1-10 °C	M
Fan Stage Up Deadband 4	8 °F	4 °C	1-20 °F / 1-10 °C	M
Fan Stage Up Deadband 5	8 °F	4 °C	1-20 °F / 1-10 °C	M
Fan Stage Down Deadband 2	8 °F	4 °C	1-25 °F / 1-13 °C	M
Fan Stage Down Deadband 3	7 °F	3.5 °C	1-25 °F / 1-13 °C	M
Fan Stage Down Deadband 4	6 °F	3 °C	1-25 °F / 1-13 °C	M
Fan Stage Down Deadband 5	5 °F	2.5 °C	1-25 °F / 1-13 °C	M
Fan Stage Down Deadband 6	5 °F	2.5 °C	1-25 °F / 1-13 °C	M
VFD Max Speed	100%		90 to 110%	M
VFD Min Speed	25%		20 to 60%	M

Note 1 – This value will follow the actual capacity while Capacity Control = Auto. Note 2 – This value will follow the actual EXV position while EXV Control = Auto.

5.7.1 Auto Adjusted Ranges

Some settings have different ranges of adjustment based on other settings.

Cool LWT 1 and Cool LWT 2

Available Mode Selection	Range Imp.	Range SI
Without Glycol	40 to 60°F	4 to 15,5°C
With Glycol	25 to 60°F	-4 to 15,5°C
With High ELWT Option	40 to 77°F	4 to 25.0°C
Evaporator Water Freeze
Available Mode Selection	Range Imp.	Range SI
Without Glycol	36 to 42°F	2 to 6 °C
With Glycol	0 to 42°F	-18 to 6 °C
Low Evaporator Pressure - Hold
Available Mode Selection	Range Imp.	Range SI
Without Glycol	28 to 45 PSIG	195 to 310 kPa
With Glycol	0 to 45 PSIG	0 to 310 kPa
Low Evaporator Pressure - Unload
Available Mode Selection	Range Imp.	Range SI
Without Glycol	26 to 45 Psig	180 to 310 kPa
With Glycol	0 to 45 Psig	0 to 410 kPa
Low Ambient Lockout
Fan VFD	Range Imp.	Range SI
= no for all circuits	35 to 60°F	2 to 15,5°C
= yes on any circuit	-10 to 60°F	-23 to 15,5°C

5.7.2 Dynamic Default Values

The fan staging dead bands have different default values based on the VFD enable setpoint. When the VFD enable setpoint is changed, a set of default values for the fan staging dead bands is loaded as follows:

Setpoint	Default w/ VFD (°C)	Default w/o VFD (°C)
Stage 0 On Deadband	2.5	4
Stage 1 On Deadband	2.5	5
Stage 2 On Deadband	4	5.5
Stage 3 On Deadband	5	6
Stage 4 On Deadband	4	6.5
Stage 5 On Deadband	4	6.5
Stage 2 Off Deadband	4	10
Stage 3 Off Deadband	3.5	8
Stage 4 Off Deadband	3	5.5
Stage 5 Off Deadband	2.5	4
Stage 6 Off Deadband	2.5	4

6.1 Calculations

6.1.1 LWT Slope

LWT slope is calculated such that the slope represents the change in LWT over a time frame of one minute with at least five samples per minute.

6.1.2 Pulldown Rate

The slope value calculated above will be a negative value as the water temperature is dropping. For use in some control functions, the negative slope is converted to a positive value by multiplying by -1.

6.2 Unit Type

A unit can be configured as Chiller or MCU (motocondensing unit). When the unit is configured as MCU the EXV control logic and all the related variables and alarms are disabled,

6.3 Unit Enable

Enabling and disabling the chiller is accomplished using set points and inputs to the chiller. The unit switch, remote switch input, and Unit Enable Set Point all are required to be on for the unit to be enabled when the control source is set to local. The same is true if the control source is set to network, with the additional requirement that the BAS request must be on.

Unit is enabled according to the following table.

NOTE: An x indicates that the value is ignored.

Unit Switch	Control Source Set Point	Remote Switch Input	Unit Enable Set Point	BAS Request	Unit Enable
Off	x	x	x	x	Off
x	x	x	Off	x	Off
x	x	Off	x	x	Off
On	Local	On	On	x	On
x	Network	x	x	Off	Off
On	Network	On	On	On	On

All of the methods for disabling the chiller, discussed in this section, will cause a normal shutdown (pumpdown) of any running circuits.

When the controller is powered up, the Unit Enable Set Point will be initialized to 'off' if the Unit Status After Power Failure Set Point is set to 'off'.

6.4 Unit Mode Selection

The operating mode of the unit is determined by setpoints and inputs to the chiller. The Available Modes Set Point determines what modes of operation can be used. This setpoint also determines whether the unit is configured for glycol use. The Control Source Set Point determines where a command to change modes will come from. A digital input switches between cool mode and ice mode if they are available and the control source is set to local. The BAS mode request switches between cool mode and ice mode if they are both available and the control source is set to network.

The Available Modes Set Point must only be changed when the unit switch is off. This is to avoid changing modes of operation inadvertently while the chiller is running.

Unit Mode is set according to the following table.

NOTE: An "x" indicates that the value is ignored.

Control Source Set Point	Mode Input	BAS Request	Available Modes Set Point	Unit Mode
x	x	x	Cool	Cool
x	x	x	Cool w/Glycol	Cool
Local	Off	x	Cool/Ice w/Glycol	Cool
Local	On	x	Cool/Ice w/Glycol	Ice
Network	x	Cool	Cool/Ice w/Glycol	Cool
Network	x	Ice	Cool/Ice w/Glycol	Ice
x	x	x	Ice w/Glycol	Ice
x	x	x	Test	Test

6.4.1 Glycol Configuration

If the Available Modes Set Point is set to an option w/Glycol, then glycol operation is enabled for the unit. Glycol operation must be disabled only when the Available Modes Set Point is set to Cool.

6.5 Unit Control States

The unit will always be in one of three states:

• Off – Unit is not enabled to run.
• Auto – Unit is enabled to run.
• Pumpdown – Unit is doing a normal shutdown.

The unit will be in the Off state if any of the following are true:

• A manual reset unit alarm is active
  • All circuits are unavailable to start (cannot start even after any cycle timers have expired)
• The unit mode is ice, all circuits are off, and the ice mode delay is active

The unit will be in the Auto state if any of the following are true:

• Unit enabled based on settings and switches
• If unit mode is ice, the ice timer has expired
• No manual reset unit alarms are active
• At least one circuit is enabled and available to start
• Low OAT Lockout is not active

The unit will be in Pumpdown until all running compressors finish pumping down if any of the following are true:

• Unit is disabled via settings and/or inputs in section 6.2
• Low OAT Lockout is triggered

6.6 Unit Status

The displayed unit status is determined by the conditions in the following table:

Enum	Status	Conditions
0	Auto	Unit State = Auto
1	Off:Ice Mode Timer	Unit State = Off, Unit Mode = Ice, and Ice Delay = Active
2	Off:OAT Lockout	Unit State = Off and Low OAT Lockout is active
3	Off:All Cir Disabled	Unit State = Off and all compressors unavailable
4	Off:Emergency Stop	Unit State = Off and Emergency Stop Input is open
5	Off:Unit Alarm	Unit State = Off and Unit Alarm active
6	Off:Keypad Disable	Unit State = Off and Unit Enable Set Point = Disable
7	Off:Remote Switch	Unit State = Off and Remote Switch is open
8	Off:BAS Disable	Unit State = Off, Control Source = Network, and BAS Enable = false
9	Off:Unit Switch	Unit State = Off and Unit Switch = Disable
10	Off:Test Mode	Unit State = Off and Unit Mode = Test
11	Auto:Noise Reduction	Unit State = Auto and Noise Reduction is active
12	Auto:Wait for load	Unit State = Auto, no circuits running, and LWT is less than the active set point + startup delta
13	Auto:Evap Recirc	Unit State = Auto and Evaporator State = Start
14	Auto:Wait for flow	Unit State = Auto, Evaporator State = Start, and Flow Switch is open
15	Auto:Pumpdown	Unit State = Pumpdown
16	Auto:Max Pulldown	Unit State = Auto, max pulldown rate has been met or exceeded
17	Auto:Unit Cap Limit	Unit State = Auto, unit capacity limit has been met or exceeded
18	Auto:Current Limit	Unit State = Auto, unit current limit has been met or exceeded

6.7 Ice Mode Start Delay

An adjustable start-to-start ice delay timer will limit the frequency with which the chiller may start in Ice mode. The timer starts when the first compressor starts while the unit is in ice mode. While this timer is active, the chiller cannot restart in Ice mode. The time delay is user adjustable.

The ice delay timer may be manually cleared to force a restart in ice mode. A set point specifically for clearing the ice mode delay is available. In addition, cycling the power to the controller will clear the ice delay timer.

6.8 Evaporator Pump Control

Three evaporator pump control states for control of the evaporator pumps:

• Off - No pump on.
• Start – Pump is on, water loop is being recirculated.
• Run – Pump is on, water loop has been recirculated.

The control state is Off when all of the following are true:

• Unit state is Off
• LWT is higher than the Evap Freeze set point or LWT sensor fault is active
• EWT is higher than the Evap Freeze set point or EWT sensor fault is active

The control state is Start when any of the following are true:

• The unit state is auto
• LWT is less than the Evap Freeze set point minus 0.6 °C and LWT sensor fault isn't active
• EWT is less than the Evap Freeze set point minus 0.6 °C and EWT sensor fault isn't active

The control state is Run when the flow switch input has been closed for a time greater than the Evaporator Recirculate set point.

6.8.1 Pump Selection

The pump output used is determined by the Evap Pump Control set point. This setting allows the following configurations:

• 1 only – Pump 1 will always be used

• 2 only – Pump 2 will always be used

• Auto – The primary pump is the one with the least run hours, the other is used as a backup

• 1 Primary – Pump 1 is used normally, with pump 2 as a backup

• 2 Primary – Pump 2 is used normally, with pump 1 as a backup

6.8.2 Primary/Standby Pump Staging

The pump designated as primary will start first. If the evaporator state is start for a time greater than the recirculate timeout set point and there is no flow, then the primary pump will shut off and the standby pump will start. When the evaporator is in the run state, if flow is lost for more than half of the flow proof set point value, the primary pump will shut off and the standby pump will start. Once the standby pump is started, the flow loss alarm logic will apply if flow cannot be established in the evaporator start state, or if flow is lost in the evaporator run state.

6.8.3 Auto Control

If auto pump control is selected, the primary/standby logic above is still used. When the evaporator is not in the run state, the run hours of the pumps will be compared. The pump with the least hours will be designated as the primary at this time.

6.9 Noise Reduction

Noise Reduction is enabled only when the Noise Reduction set point is enable. Noise Reduction is in effect when enabled via the set point, the unit mode is cool, and the unit controller clock time is between the Noise Reduction start time and end time.

When Noise Reduction is in effect, the Maximum Reset is applied to the cool LWT set point. However, if any reset type is selected, that reset will continue to be used rather than the maximum reset. Also, the saturated condenser target for each circuit will be offset by the Noise Reduction Condenser Target Offset.

6.10 Leaving Water Temperature (LWT) Reset

6.10.1 LWT Target

The LWT Target varies based on settings and inputs and is selected as follows:

Control Source Set Point	Mode Input	BAS Request	Available Modes Set Point	Base LWT Target
Local	OFF	X	COOL	Cool Set Point 1
Local	ON	X	COOL	Cool Set Point 2
Network	X	X	COOL	BAS Cool Set Point
Local	OFF	X	COOL w/Glycol	Cool Set Point 1
Local	ON	X	COOL w/Glycol	Cool Set Point 2
Network	X	X	COOL w/Glycol	BAS Cool Set Point
Local	OFF	x	COOL/ICE w/Glycol	Cool Set Point 1
Local	ON	x	COOL/ICE w/Glycol	Ice Set Point
Network	x	COOL	COOL/ICE w/Glycol	BAS Cool Set Point
Network	x	ICE	COOL/ICE w/Glycol	BAS Ice Set Point
Local	x	x	ICE w/Glycol	Ice Set Point
Network	x	x	ICE w/Glycol	BAS Ice Set Point

6.10.2 Leaving Water Temperature (LWT) Reset

The base LWT target may be reset if the unit is in Cool mode and it is configured for a reset. The type of reset to be used is determined by the LWT Reset Type set point.

When the active reset increases, the Active LWT Target is changed at a rate of 0.1^ C every 10 seconds. When the active reset decreases, the Active LWT Target is changed all at once.

After resets are applied, the LWT target can never exceed a value of 15,5°C (if the High ELWT Option is not present).

6.10.2.1 Reset Type - None

The Active Leaving Water variable is set equal to the current LWT set point.

6.10.2.2 Reset Type - Return

The Active Leaving Water variable is adjusted by the return water temperature.

Return Reset

graph TD
    A["Active LWT"] --> B["LWT set Point"]
    B --> C["Max Reset"]
    C --> D["LWT set Point+Max Reset"]
    D --> E["Start Reset Delta T"]

The active set point is reset using the following parameters:

1. Cool LWT set point
2. Max Reset set point

3. Start Reset Delta T set point

4. Evap Delta T

Reset varies from 0 to Max Reset set point as the Evaporator EWT - LWT (Evap delta t) varies from the Start Reset Delta T set-point to 0.

6.10.3 4-20 mA External Signal Reset

The Active Leaving Water variable is adjusted by the 4 to 20 mA reset analog input.

Parameters used:

1. Cool LWT set point
2. Max Reset set point
3. LWT Reset signal

Reset is 0 if the reset signal is less than or equal to 4 mA. Reset is equal to the Max Reset Delta T set point if the reset signal equals or exceeds 20 mA. The amount of reset will vary linearly between these extremes if the reset signal is between 4 mA and 20 mA. An example of the operation of 4-20 reset in Cool mode follows.

4-20 mA Reset - Cool Mode

6.10.4 Outside Air Temperature (OAT) Reset

The Active Leaving Water variable is reset based on the outdoor ambient temperature. Parameters used:

1. Cool LWT set point
2. Max Reset set point
3. OAT

Reset is 0 if the outdoor ambient temperature is greater than Start Reset OAT set point. From Start Reset OAT set point down to Max Reset OAT the reset varies linearly from no reset to the max reset at Max Reset OAT set point. At ambient temperatures less than Max Reset OAT set point, reset is equal to the Max Reset set point.

graph LR
    A["Active LWT"] --> B["Cool LWT+Max Reset"]
    B --> C["Max Reset"]
    C --> D["Cool LWT Set-Point"]
    D --> E["OAT"]

6.11 Unit Capacity Control

Unit capacity control is performed as described in this section.

6.11.1 Compressor Staging in Cool Mode

The first compressor on the unit is started when evaporator LWT is higher than the target plus the Startup Delta T set point. An additional compressor is started when Evaporator LWT is higher than the target plus the Stage Up Delta T set point. When multiple compressors are running, one will shut down if evaporator LWT is lower than the target minus the Stage Down Delta T set point.

The last compressor running will shut down when the evaporator LWT is lower than the target minus the Shut Down Delta T set point.

6.11.1.1 Stage Up Delay

A minimum amount of time will pass between compressors starting, which is defined by the Stage Up Delay set point. This delay will only apply when at least one compressor is running. If the first compressor starts and quickly fails on an alarm, another compressor will start without this minimum time passing.

6.11.1.2 Required Load For Stage Up

An additional compressor will not be started until all running compressors are at a capacity higher than the Load Stage Up set point, or running in a limited state.

6.11.1.3 Light Load Stage Down

When multiple compressors are running, one will shut down if all running compressors are at a capacity lower than the Load Stage Down set point and the evaporator LWT is less than the target plus the Stage Up Delta T set point. A minimum amount of time will pass between compressors stopping as a result of this logic, which is defined by the Stage Down Delay set point.

6.11.1.4 Maximum Circuits Running

If the number of compressors running is equal to the Max Circuits Running set point, no additional compressors will be started.

When multiple compressors are running, one will shut down if the number of compressors running is more than the Max Circuits Running set point.

6.11.2 Compressor Staging in Ice Mode

The first compressor will start when evaporator LWT is higher than the target plus the Startup Delta T set point. When at least one compressor is running, the other compressors will start only when evaporator LWT is higher than the target plus the Stage Up Delta T set point. All compressors will be staged off when evaporator LWT is less than the target.

6.11.2.1 Stage Up Delay

A fixed stage up delay of one minute between compressor starts is used in this mode. When at least one compressor is running, the other compressors will start as quickly as possible with respect to the stage up delay.

6.11.3 Staging Sequence

This section defines which compressor is the next one to start or stop. In general, compressors with fewer starts will normally start first, and compressors with more run hours will normally stop first. Compressor staging sequence can also be determined by an operator defined sequence via setpoints.

6.11.3.1 Next To Start

The next compressor to start must meet the following requirements:

Lowest sequence number of those compressors available to start

• -if sequence numbers are equal, it must have the least starts
• -if starts are equal, it must have least run hours
• -if run hours are equal, it must be the lowest numbered compressor

6.11.3.2 Next To Stop

The next compressor to shut down must meet the following requirements:

Lowest sequence number of the compressors that are running

• -if sequence numbers are equal, it must have the most run hours
• -if run hours are equal, it must be the lowest numbered compressor

6.11.4 Compressor Capacity Control In Cool Mode

In Cool mode, evaporator LWT is controlled to within 0.2^ C of the target under constant flow conditions by controlling capacity of the individual compressors.

Compressors are loaded with a fixed step scheme. The rate of capacity adjustment is determined by the time between capacity changes. The farther away from the target, the faster compressors will be loaded or unloaded.

The logic projects ahead to avoid overshoot, such that the overshoot does not cause the unit to shut off due to evaporator LWT dropping below the target minus the Shutdown Delta T set point while there is still a load on the loop at least equal to the minimum unit capacity.

Capacity of the compressors is controlled so that when possible their capacities are balanced.

Circuits that are running in manual capacity control or running with active capacity limiting events are not considered in the capacity control logic.

The compressor capacities are adjusted one at a time while maintaining a capacity imbalance that does not exceed 12.5%.

6.11.5 Load/Unload Sequence

This section defines which compressor is the next one to load or unload.

6.11.5.1 Next To Load

The next compressor to load meets the following requirements:

Lowest capacity of the running compressors that can load up

• if capacities are equal, it must have the highest sequence number of the compressors that are running
• if the sequence numbers are equal, it must have the least run hours
• if run hours are equal, it must have the most starts
• if starts are equal, it must be the highest numbered compressor

6.11.5.2 Next To Unload

The next compressor to unload must meet the following requirements:

Highest capacity of the running compressors

• if capacities are equal, it must have the lowest sequence number of the compressors that are running
- if sequence numbers are equal, it must have the most run hours
- if run hours are equal, it must have the least starts
- if starts are equal, it must be the lowest numbered compressor

6.11.6 Compressor Capacity Control In Ice Mode

In Ice mode, running compressors are loaded up simultaneously at the maximum possible rate that allows for stable operation of the individual circuits.

6.12 Unit Capacity Overrides

Unit capacity limits can be used to limit total unit capacity in Cool mode only. Multiple limits may be active at any time, and the lowest limit is always used in the unit capacity control.

Soft load, demand limit, and network limit use a deadband around the actual limit value, such that unit capacity increase is not allowed within this deadband. If unit capacity is above the deadband, capacity is decreased until it is back within the deadband.

• For 2 circuit units, the deadband is 7% .
• For 3 circuit units, the deadband is 5% .
• For 4 circuit units, the deadband is 4% .

6.12.1 Soft Load

Soft Loading is a configurable function used to ramp up the unit capacity over a given time. The set points that control this function are:

• Soft Load – (ON/OFF)
• Begin Capacity Limit – (Unit %)
• Soft Load Ramp – (seconds)

The Soft Load Unit Limit increases linearly from the Begin Capacity Limit set-point to 100% over the amount of time specified by the Soft Load Ramp set-point. If the option is turned off, the soft load limit is set to 100%.

6.12.2 Demand Limit

The maximum unit capacity can be limited by a 4 to 20 mA signal on the Demand Limit analog input at the unit controller. This function is only enabled if the Demand Limit set point is set to ON.

As the signal varies from 4 mA up to 20 mA, the maximum unit capacity changes by steps of 1% from 100% to 0%. The unit capacity is adjusted as needed to meet this limit, except that the last running compressor cannot be turned off to meet a limit lower than the minimum unit capacity.

6.12.3 Network Limit

The maximum unit capacity can be limited by a network signal. This function is only enabled if the unit control source is set to network. The signal will be received through the BAS interface on the unit controller.

As the signal varies from 0% up to 100%, the maximum unit capacity changes from 0% to 100%. The unit capacity is adjusted as needed to meet this limit, except that the last running compressor cannot be turned off to meet a limit lower than the minimum unit capacity.

6.12.4 Current Limit

Current Limit control is enabled only when the current limit enable input is closed.

Unit current is calculated based on the 4-20 mA input that receives a signal from an external device. The current at 4 mA is assumed to be 0, and the current at 20 mA is defined by a set point. As the signal varies from 4 to 20 mA, the calculated unit current varies linearly from 0 amps to the amp value defined by the set point.

The current limit uses a deadband centered around the actual limit value, such that unit capacity increase is not allowed when current is within this deadband. If unit current is above the deadband, capacity is decreased until it is back within the deadband. The current limit deadband is 10% of the current limit.

6.12.5 Maximum LWT Pulldown Rate

The maximum rate at which the leaving water temperature can drop is limited by the Maximum Rate set point, only when the LWT is less than 60^ F (15,5°C).

If the pulldown rate is too fast, the unit capacity is reduced until the rate is less than the Maximum Pulldown Rate set point.

6.12.6 High Water Temperature Capacity Limit

If the evaporator LWT exceeds 18^ C, compressor load will be limited to a maximum of 75%. Compressors will unload to 75% or less if running at greater than 75% load when the LWT exceeds the limit. This feature is to keep the circuit running within the capacity of the condenser coil.

A dead-band placed below the limit set-point will be used to increase function stability. If the actual capacity is in the band, unit loading will be inhibited.

6.13 Daikin on Site

The Daikin on Site(DoS) page can be accessed navigating through Main Menu → View/Set Unit → Daikin On Site.

Info 1 Daikin On Site Comm Start= Off Comm State= - Serial Nr= 3173 Authorization Key= VJTCLK-HHDIE-ULLLC-SYKXV-WOAC ESC OK

In order to use the DoS utility, the customer has to communicate the Serial Number to Daikin company and subscribe to the DoS service. Then, from this page, it is possible to:

- Start/Stop the DoS connectivity

- Check the connection status to DoS service

according to the parameters shown into the table below.

Parameter	Range	Description
Comm Start	Off	Stop the connection to DoS
	Start	Start the connection to DoS
Comm State	-	Connection to DoS is off
	IPErr	Connection to DoS cannot be established
	Connected	Connection to DoS is established and working

6.14 Heat Recovery

When the Heat Recovery switch is set to Enable and at least one circuit has Heat Recovery option enabled Heat Recovery operations are initiated on the running circuits. The control will control the Heat Recovery heat exchanger leaving water temperature to the setpoint (50°C). When the Heat Recovery leaving water temperature exceeds the setpoint by a differential (3°C) the recovery function is disabled until the temperature drops below the setpoint.

Heat Recovery function is disabled if the Heat Recovery heat exchanger entering water temperature is below a minimum allowed value (25°C).

Three Heat Recovery states are possible:

• Off - Heat Recovery operations Off
• Start: Heat Recovery water is being recirculated
  • Run: Heat Recovery is On

The Heat Recovery state is Off when one of the following is true:

• Heat Recovery Switch is set to Disable
• Heat Recovery option is not installed on at least one of the circuits available
• Heat Recovery entering water temperature is below the minimum allowed temperature
• Heat Recovery EWT sensor is out of range
• Heat Recovery LWT sensor is out of range

The Heat Recovery state is start if all of the following are true:

• Heat Recovery option is installed on any of the circuits available
• Heat Recovery entering water temperature is above the minimum allowed temperature
• Heat Recovery EWT sensor is in range
• Heat Recovery LWT sensor is in range
• Heat Recovery LWT is higher than Setpoint + Differential

The Heat Recovery state is Run if all of the following are true:

• Heat Recovery option is installed on at least one of the circuits available
• Heat Recovery entering water temperature is above the minimum allowed temperature
  • Heat Recovery EWT sensor is in range
• Heat Recovery LWT sensor is in range
• Heat Recovery LWT is lower than Setpoint,

6.15 Heat Recovery Pump

Two Heat Recovery Pump control states are possible for control the Heat Recovery Pump:

• Off - Pump Off.
• Run – Pump is on.

The control state is Off if all of the following are true:

• Heat Recovery state is Off
• Heat Recovery EWT is higher than the Evap Freeze set point and Heat Recovery EWT sensor fault is not active
• Heat Recovery LWT is higher than the Evap Freeze set point and Heat Recovery LWT sensor fault is not active

The control state is Run when any of the following is true

• Heat Recovery state is Start or Run
  • Heat Recovery EWT is lower than the Evap Freeze set point or Heat Recovery EWT sensor fault is active
  • Heat Recovery LWT is lower than the Evap Freeze set point or Heat Recovery LWT sensor fault is active

6.16 Rapid Restart

This chiller can activate a Rapid Restart (optional) sequence in reaction to a power failure. This option allows the unit to restore the load it had before the power failure in less time, reducing the standard cycle timer.

In order to Enable the Rapid Restart functionality, the customer must set to Yes the "Rapid Restart" parameter in the Rapid Restart page, and, if present, the Switch state of RR option should be in the enable position.

The feature is configured in the factory.

The 'Rapid Restart' page can be accessed navigating through Main Menu → View/Set Unit → Rapid_Restart.

View/Set Unit Status/Settings Set-Up Temperatures Date/Time/Schedules Power Conservation Rapid_Restart Configuration Ctrlr IP Setup

Info 2 Rapid Restart Rapid Restart Enable Input Switch State Off State Disabled Power C ESC OK

The "State" represents the actual state of the Rapid Restart option.

The "Input Switch State" represents the state of the hardware switch if it is present in the unit.

If the State of the option is "Disabled", it means that or the HMI enable setpoint or the input switch is off, or both. Could be possible also that the unit were not well configured and lead to the impossibility to enable the RR option.

Rapid restart is activated under the following conditions:

• The power failure exists for up to 180 seconds
• The unit and circuit switches are ON.
- No unit or circuit alarms exist.
- The unit has been running in the normal Run state.
- The BMS Circuit Mode setpoint is set to Auto when the control source is Network.
- The ELWT isn't lower than the "ELWT Setpoint + StgUpDT".

For the EWAD units, the possibility to employ a set of software options has been added to the functionality of the chiller, in according with the new Microtech 4 installed on the Unit. The Software Options do not require any additional hardware and regard communication channels

During the commissioning the machine is delivered with the Option Set chosen by the customer; the Password inserted is permanent and depends on the Serial Machine Number and the Option Set selected. In order to check the current Option Set:

Main Menu → Commission Unit → Option SW

Info 1 Commission Unit Save Settings= Passive About Chiller Configure Unit Configure Circuits Software Update Set-Up Option SW Date/Time/Schedules

Info Software Options Apply Changes No Password Value 1-Modbus Slave MSTP Off 1-State Off 2-BACNet MSTP Off 2-State Off 3-BACNet IP Off 3-State Off

Parameter	Description
Password	Writable by Interface/Web Interface
Option Name	Option Name
Option Status	Option is activated.
	Option is not activated

The Current Password inserted activates the selected options.

The Option Set and the Password are updated in the Factory. If the customer wants to change its Option Set, he needs to contact the Daikin Personnel and asks for a new password.

As soon as the new password is communicated, the follow steps allow the customer to change the Option Set by himself:

1. Wait for the circuits are both OFF, then, from the Main Page,
   Go to Main Menu → Commission Unit → Software Options
2. Select the Options to Activate
3. Insert the Password
4. Wait for the States of the selected options going to On
5. Apply Changes→Yes (it will reboot the controller)

The Password is changeable only if the machine is working in safe conditions: both the circuits are in the State Off.

7.1 Inserting the Password in a Spare Controller

If the Controller is broken and/or it needs to be replaced for any reason, the customer needs to configure the Option Set with a new Password.

If this replacement is scheduled, the customer can ask to Daikin Personnel for a new Password and repeat the steps in chapter 4.15.1.

If there is no enough time to ask for a Password to Daikin Personnel (ex. an expected failure of the controller), a set of Free Limited Password is provided, in order not to interrupt the machine's working. These Passwords are free and visualized in:

Main Menu→Commission Unit→Configuration→Option SW→Temporary Passwords

Info 1 Software Options 4-Energy Monitoring Off 4-State Off 5-iCM Standard Off 5-State Off 6-iCM Advanced Off 6-State Off Temporary Passwords Apply Changes No ESC OK

Info 1 Temporary Passwords 1-553489691893 Not Used 2-411486702597 Not Used 3-084430952438 Not Used Node Permanent Timer 0min

Their Use is limited up to three months:

• 553489691893 – 3 Months Duration
• 411486702597 – 1 Month Duration
• 084430952438 – 1 Month Duration

It gives the customer the time enough to contact Daikin Service and insert a new unlimited password.

Parameter	Specific Status	Description
553489691893		Activate the Option Set for 3 Months.
411486702597		Activate the Option Set for 1 Month.
084430952438		Activate the Option Set for 1 Month.
Mode	Permanent	A permanent Password is inserted. Option set can be used for unlimited time.
	Temporary	A temporary Password is inserted. Option set can be used depending on the password inserted.
Timer		Last duration of the Option Set activated. Enabled only if the mode is Temporary.

The Password is changeable only if the machine is working in safe conditions: both the circuits are in the State Off.

7.1.1 Modbus MSTP Software Option

When the software option "Modbus MSTP" is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:

Main Menu→Commission Unit→SW Modbus MSTP

Info 1 Commission Unit Configuration Alarm Limits Manual Control Input/Output Sensors Calibration SW Modbus MSTP Scheduled Maintenance

The values that can be set are the same as those found on the Modbus MSTP option page with the relative driver, and depend on the specific system where the unit is installed.

Info 1 Modbus MSTP Address 1 Baudrate 19200 Parity None 2StopBits No Delay 100 Response Timeout 100 ESC OK

To establish the connection, the RS485 port to use is the one on the T14 terminal of the MT4 controller.

7.1.2 BACNET MSTP

When the software option "BACNet MSTP" is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:

Main Menu→Commission Unit→SW BACNet MSTP

Info 1 Commission Unit Configuration Alarm Limits Manual Control Input/Output Sensors Calibration SW BACNet MSTP Scheduled Maintenance

The values that can be set are the same as those found on the BACNet MSTP option page with the relative driver, and depend on the specific system where the unit is installed.

Info 1 BACNet MSTP Device Instance 1 Name Value Status NoActivePo Address 0 Baudrate 38400 Max Master 1 Max Info Frame 1 Unit System 0 ESC OK

To establish the connection, the RS485 port to use is the one on the T14 terminal of the MT4 controller.

7.1.3 BACNET IP

When the software option "BACNet IP" is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:

Main Menu→Commission Unit→SW BACNet IP

Info 1 Commission Unit Configuration Alarm Limits Manual Control Input/Output Sensors Calibration SW BACNet IP Scheduled Maintenance

The values that can be set are the same as those found on the BACNet MSTP option page with the relative driver, and depend on the specific system where the unit is installed.

Info BACNet IP Device ID 1 Name Value Status OK UDP Port 47808 Unit System 0 Act IP= 192.168.001.042 Act Msk= 255.255.255.000 Act Gwv= 192.168.001.001

The port for LAN connection to be used for BACNet IP communication is the T-IP Ethernet port, the same one used for remote control of the controller on the PC.

8.1 Calculations

8.1.1 Refrigerant Saturated Temperature

Refrigerant saturated temperature is calculated from the pressure sensor readings for each circuit. A function provides the converted value of temperature to match values published data for R134a

-within 0.1 °C for pressure inputs from 0 kPa to 2070kPa,

-within 0.2 °C for pressure inputs from -80 kPa to 0 kPa.

8.1.2 Evaporator Approach

The evaporator approach is calculated for each circuit. The equation is as follows: Evaporator Approach = LWT - Evaporator Saturated Temperature

8.1.3 Suction Superheat

Suction superheat is calculated for each circuit using the following equation: Suction superheat = Suction Temperature - Evaporator Saturated Temperature

8.1.4 Discharge Superheat

Discharge superheat is calculated for each circuit using the following equation: Discharge superheat = Discharge Temperature - Condenser Saturated Temperature

8.1.5 Oil Differential Pressure

Oil Differential Pressure is calculated for each circuit with this equation: Oil Differential Pressure = Condenser Pressure - Oil Pressure

8.1.6 Maximum Saturated Condenser Temperature

The maximum saturated condenser temperature calculation is modeled after the compressor operational envelope. Its value is 68.3^ C basically but it can change when saturated evaporator temperature decreases below 0^ C.

8.1.7 High Saturated Condenser – Hold Value

High Cond Hold Value = Max Saturated Condenser Value - 2.78°C

8.1.8 High Saturated Condenser – Unload Value

High Cond Unload Value = Max Saturated Condenser Value - 1.67°C

8.1.9 Condenser Saturated Temperature Target

The saturated condenser temperature target is calculated to maintain the proper pressure ratio, to keep the compressor lubricated and to have the maximum circuit performances.

The calculated target value is limited to a range defined by the Condenser Saturated Temperature Target min and max set points. These set points simply cut off the value to a working range, and this range can be limited to a single value if the two set points are set to the same value.

8.1.10 Heat Recovery Condenser Saturated Temperature Target

When Heat Recovery mode is enabled the condenser saturated temperature target is calculated in order to produce additional heat rejection at the condenser coils to heat the water to the desired temperature. To increase the efficiency of the chiller the target depends on the evaporator LWT so that the closer to the LWT setpoint the higher the amount of heat recovered to the water.

The target is limited to a range defined by the Heat Recovery Saturated Temperature Target min and max set points. These setpoints simply cut off the value to a working range, and this range can be limited to a single value if the two set points are set to the same value.

8.2 Circuit Control Logic

8.2.1 Circuit Availability

A circuit is available to start if the following conditions are true:

• Circuit switch is closed
• No circuit alarms are active
• Circuit Mode set point is set to Enable
  • BAS Circuit Mode set point is set to Auto
• No cycle timers are active

- Discharge Temperature is at least 5^ higher than Oil Saturated Temperature

8.2.2 Starting

The circuit will start if all these conditions are true:

• Adequate pressure in the evaporator and condenser (see No Pressure At Start Alarm)
• Circuit Switch is closed
• Circuit Mode set point is set to Enable

• BAS Circuit Mode set point is set to Auto
- No cycle timers are active
- No alarms are active
• Staging logic requires this circuit to start
- Unit state is Auto
• Evaporator pump state is Run

8.2.2.1 Circuit Startup Logic

Circuit startup is the time period following the starting of the compressor on a circuit. During the startup, the low evaporator pressure alarm logic is ignored. When the compressor has been running at least 20 seconds and the evaporator pressure rises above the low evaporator pressure unload set point, the startup is complete.

If the pressure does not rise above the unload set point and the circuit has been running longer than the Startup Time set point, then the circuit is turned off and an alarm triggered. If the evaporator pressure drops below the absolute low pressure limit then the circuit is turned off and the same alarm triggered.

8.2.2.2 Low OAT Restart Logic

Low OAT restart logic allows multiple start attempts in low ambient conditions. If the condenser saturated temperature is less than 60^ F when the compressor starts, the startup is considered to be a 'low OAT start'. If a low OAT start is not successful the circuit is shut down, but no alarm is triggered for the first two attempts of the day. If a third low OAT start attempt fails, then the circuit is shut down and the Low OAT Restart Alarm is triggered.

The restart counter is reset when a startup is successful, the Low OAT Restart alarm is triggered, or the unit time clock shows that a new day has started.

8.2.2.3 Stopping

8.2.2.4 Normal Shutdown

A normal shutdown requires the circuit to pumpdown before the compressor is turned off. This is done by closing the EXV, and closing the liquid line solenoid (if present) while the compressor is running.

The circuit will do a normal shutdown (pumpdown) if any of the following are true:

• Staging logic requires this circuit to stop
• Unit State is Pumpdown
- A pumpdown alarm occurs on the circuit
- Circuit switch is open
- Circuit Mode set point is set to Disable
- BAS Circuit Mode set point is set to Off
The normal shutdown is complete when any of the following are true:
- Evaporator Pressure is less than the Pumpdown Pressure set point
- Service Pumpdown set point is set to Yes and Evaporator Pressure is less than 35 kPa
- Circuit has been pumping down for longer than the Pumpdown Time Limit setpoint

8.2.2.5 Rapid Shutdown

A rapid shutdown requires the compressor to stop and the circuit to go to the Off state immediately.

The circuit will do a rapid shutdown if either of these conditions occurs at any time:

- Unit State is Off

- A rapid stop alarm occurs on the circuit

8.3 Circuit Status

The displayed circuit status is determined by the conditions in the following table:

Enum	Status	Conditions
0	Off:Ready	Circuit is ready to start when needed.
1	Off:Stage Up Delay	Circuit is off and cannot start due to stage up delay.
2	Off:Cycle Timer	Circuit is off and cannot start due to active cycle timer.
3	Off:Keypad Disable	Circuit is off and cannot start due to keypad disable.
4	Off:Circuit Switch	Circuit is off and circuit switch is off.
5	Off:Refr In Oil Sump	Circuit is off and Discharge Temperature – Oil Saturated Temperature at gas pressure <= 5°C
6	Off:Alarm	Circuit is off and cannot start due to active circuit alarm.
7	Off:Test Mode	Circuit is in test mode.
8	EXV Preopen	Circuit is in preopen state.
9	Run:Pumpdown	Circuit is in pumpdown state.
10	Run:Normal	Circuit is in run state and running normally.
11	Run:Disc SH Low	Circuit is running and cannot load due to low discharge superheat.
12	Run:Evap Press Low	Circuit is running and cannot load due to low evaporator pressure.
13	Run:Cond Press High	Circuit is running and cannot load due to high condenser pressure.

8.4 Compressor Control

The compressor will run only when the circuit is in a run or pumpdown state. This means the compressor should not be running any time the circuit is off or during preopening the EXV.

A minimum time between starts of the compressor and a minimum time between shutdown and start of the compressor will be enforced. The time values are set by global circuit set points.

These cycle timers are enforced even through cycling of power to the chiller.

These timers may be cleared via a setting on the controller.

8.4.1.2 Compressor Run Timer

When a compressor starts, a timer will start and run as long as the compressor runs. This timer is used in the alarm log.

8.4.1.3 Compressor Capacity Control

After starting, the compressor will be unloaded to the minimum physical capacity and no attempt to increase compressor capacity is made until the differential between evaporator pressure and oil pressure meets a minimum value.

After the minimum differential pressure is met, compressor capacity is controlled to 25%.

Compressor capacity will always be limited to a minimum of 25% while it is running, except for the time after compressor start when the differential pressure is being built and except when changes to capacity are performed as needed to meet unit capacity requirements (see unit capacity control section).

Capacity will not be increased above 25% until discharge superheat has been at least 12°C for a time of at least 30 seconds.

8.4.1.4 Manual capacity control

The capacity of the compressor can be controlled manually. Manual capacity control is enabled via a set point with choices of auto or manual. Another set point allows setting the compressor capacity from 25% to 100%.

The compressor capacity is controlled to the manual capacity set point. Changes will be made at a rate equal to the maximum rate that allows stable circuit operation.

Capacity control reverts back to automatic control if either:

• the circuit shuts down for any reason

- capacity control has been set to manual for four hours

8.4.1.5 Slide Control Solenoids (Asymmetric compressors)

This section applies to the following compressor models (asymmetric):

Model	Name plate
F3AS	HSA192
F3AL	HSA204
F3BS	HSA215
F3BL	HSA232
F4AS	HSA241
F4AL	HSA263

The required capacity is achieved by controlling one modulating slide and one non-modulating slide. The modulating slide can control 10% to 50% of the total compressor capacity, infinitely variable. The non-modulating slide can control either 0% or 50% of the total compressor capacity.

Either the load or the unload solenoid for the non-modulating slide is on any time the compressor is running. For compressor capacity from 10% up to 50%, the non-modulating slide unload solenoid is on to keep that slide in the unloaded position. For capacity from 60% to 100%, the non-modulating slide load solenoid is on to keep that slide in the loaded position.

The modulating slide is moved by pulsing of the load and unload solenoids to achieve the required capacity.

An additional solenoid is controlled to assist in moving the modulating slide in certain conditions. This solenoid is activated when the pressure ratio (condenser pressure divided by evaporator pressure) is less than or equal to 1.2 for at least 5 seconds. It is deactivated when pressure ratio is more than 1.2.

8.4.1.6 Slide Control Solenoids (Symmetric compressors)

This section applies to the following compressor models (asymmetric):

Model	Name plate
F4221	HSA205
F4222	HSA220
F4223	HSA235
F4224	HSA243
F3216	HSA167
F3218	HSA179
F3220	HSA197
F3221	HSA203
F3118	HSA3118
F3120	HSA3120
F3121	HSA3121
F3122	HSA3122
F3123	HSA3123

The required capacity is achieved by controlling one modulating slide. The modulating slide can control 25% to 100% of the total compressor capacity, infinitely variable.

The modulating slide is moved by pulsing of the load and unload solenoids to achieve the required capacity.

8.4.1.7 Capacity Overrides – Limits of Operation

The following conditions override automatic capacity control when the chiller is in COOL mode. These overrides keep the circuit from entering a condition in which it is not designed to run.

8.4.1.8 Low Evaporator Pressure

If the Low Evaporator Pressure Hold event is triggered, the compressor will not be allowed to increase in capacity. If the Low Evaporator Pressure Unload event is triggered, the compressor will begin reducing capacity. The compressor will not be allowed to increase in capacity until the Low Evaporator Pressure Hold event has cleared. See the Circuit Events section for details on triggering, reset, and unloading action.

8.4.1.9 High Condenser Pressure

If the High Condenser Pressure Hold event is triggered, the compressor will not be allowed to increase capacity. If the High Condenser Pressure Unload event is triggered, the compressor will begin reducing capacity. The compressor will not be allowed to increase in capacity until the High Condenser Pressure Hold event has cleared. See the Circuit Events section for details on triggering, reset, and unloading action.

8.5 Condenser Fan Control

The compressor must be running in order to stage fans on. All running fans will turn off when compressor goes to the off state.

8.5.1 Saturated Condenser Temperature Target

The condenser fan control logic attempts to control the saturated condenser temperature to a calculated target. A base condenser target is calculated based on evaporator saturated temperature This value is then limited to a maximum and minimum determined by the Condenser Target Maximum and Minimum set points. If these set points are both set to the same value, then the saturated condenser temperature target will be locked at that value.

8.5.2 Heat Recovery Saturated Condenser Temperature Target

When Heat Recovery operation is initiated the condenser temperature target is changed respect to normal operation. When the LWT Error changes between 2 and 8°C the condenser temperature target is changed between Heat Recovery Saturated Condeneser Temperature Max and Min respectively. This allows the circuit to recover more when the LWT is close to the temperature target.

8.5.2.1 Fan Staging

The fan stage is adjusted in steps of 1 fan. The only exception is to accommodate forced fan staging at compressor start. Fan staging will accommodate anywhere from 5 to 12 fans according to the table below:

Output Number						# of fans
1	2	3	4	5	6
*	*	**	*			5
*	*	**	**			6
*	*	**	**	*		7
*	*	**	**	**		8
*	*	**	**	***		9
*	*	**	**	***	*	10
*	*	**	**	***	**	11
*	*	**	**	***	***	12

8.5.2.2 Staging Up

Six stage-up deadbands are used. Stages one through five use their respective dead bands. Stages six through twelve all use the sixth stage up dead band.

When the saturated condenser temperature is above the Target + the active deadband, a Stage Up error is accumulated. The Stage Up Error Step is added to Stage Up Accumulator. When Stage Up Error Accumulator exceeds a limit another stage is added.

Under specific conditions the Accumulator is reset to zero to avoid Accumulator saturation.

8.5.2.3 Staging Down

Five stage down dead bands are used. Stages two through five use their respective dead bands. Stages six through twelve all use the stage six dead band.

When the saturated condenser refrigerant temperature is below the Target – the active deadband, a Stage Down error is accumulated.

The Stage Down Error Step is added to Stage Down Accumulator. When the Stage Down Error exceeds a limit another stage of condenser fans is removed.

When one fan is running, a fixed point is used in place of a deadband.

Under specific conditions the Accumulator is reset to zero to avoid Accumulator saturation.

8.5.2.4 VFD

Condenser pressure trim control is accomplished using an optional VFD on the first fan. This VFD control varies the fan speed to drive the saturated condenser temperature to a target value. The target value is normally the same as the saturated condenser temperature target.

8.5.2.5 VFD State

The VFD speed signal is always 0 when the fan stage is 0.

When the fan stage is greater than 0, the VFD speed signal is enabled and controls the speed as needed.

8.5.2.6 Stage Up Compensation

In order to create a smoother transition when another fan is staged on, the VFD compensates by slowing down initially. This is accomplished by adding the new fan stage up deadband to the VFD target. The higher target causes the VFD logic to decrease fan speed. Then, every 5 seconds, 0.1°F is subtracted from the VFD target until it is equal to the saturated condenser temperature target set point. This will allow the VFD to slowly bring the saturated condenser temperature back down.

8.6 EXV Control (for chiller units)

The control is able to support different valve models from different vendors. When a model is selected, all the operational data for that valves are set including phase and hold currents, total steps, motor speed and extrasteps.

The EXV is moved at a rate which depends on the valve model, with a total range of steps. Positioning is determined as described in the following sections, with adjustments made in increments of 0.1% of the total range.

8.6.1.1 Preopen Operation

The EXV control includes a preopen operation that is used only when the unit has optional liquid line solenoids. The unit is configured for use with or without liquid line solenoids via a set point.

When a circuit start is required, the EXV opens before the compressor starts. The preopen position is defined by a set point. The time allowed for this preopen operation is at least enough time for the EXV to open to the preopen position based on the programmed movement rate of the EXV.

8.6.1.2 Startup Operation

When the compressor starts (if no liquid line solenoid valve is installed), the EXV will start to open to an initial position that allows a safe start up. The value of LWT will determine if it is possible to enter the normal operation. If it is higher than 20^ C then a pressostatic (constant pressure) control will start to keep the compressor into the envelope. It goes in normal operation as soon as the suction superheat drops below a value equal to the suction superheat setpoint.

8.6.1.3 Normal Operation

Normal operation of the EXV is used when the circuit has completed startup operation of the EXV and is not in a slide transition conditions.

During normal operation, the EXV controls suction superheat to a target that can vary in a pre-defined range

The EXV controls the suction superheat within 0.55°C during stable operating conditions (stable water loop, static compressor capacity, and stable condensing temperature).

The target value is adjusted as needed to maintain discharge superheat within a range from 15°C to 25°C.

8.6.1.4 Maximum Operating Pressures

The EXV control maintains the evaporator pressure in the range defined by the maximum operating pressure.

If the leaving water temperature is higher than 20^ C at startup or if the pressure becomes higher than 350 kPa during normal operations, then a pressostatic (constant pressure) control will be started to keep the compressor in the envelope. Maximum operating pressure is 350 kPa. It switches back to normal operation as soon as the suction superheat drops below a pre-defined value.

8.6.1.5 Response to Compressor Capacity Change

The logic will consider transition from 50% to 60% and from 60% to 50% as special conditions. When a transition is entered the valve opening will change to adapt to the new capacity, this new calculated position will be kept for 60 seconds. The valve opening will be increased during 50% to 60% transition and decreased in 60% to 50% transition.

Purpose of this logic is to limit liquid flood back when changing from 50% to 60% if the capacity increases above 60% due to slides movement.

8.6.1.6 Manual Control

The EXV position can be set manually. Manual control can only be selected when the EXV state is Pressure or Superheat control. At any other time, the EXV control set point is forced to auto.

When EXV control is set to manual, the EXV position is equal to the manual EXV position setting. If set to manual when the circuit state transitions from run to another state, the control setting is automatically set back to auto. If EXV control is changed from manual back to auto while the circuit state remains run, the EXV state goes back to the normal operations if possible or to pressure control to limit maximum operating pressure.

8.6.1.7 Transitions Between Control States

Whenever EXV control changes between Startup Operation, Normal Operation, or Manual Control, the transition is smoothed by gradually changing the EXV position rather than changing all at once. This transition prevents the circuit from becoming unstable and resulting in a shutdown due to alarm trip.

8.7 Economizer Control

The economizer is activated when a circuit is in a run state and capacity exceeds 95%.

It turns off when the load drops below 60% or the circuit is no longer in a run state.

8.8 Subcooler Control

The subcooler is always activated when a circuit is in a run state and the economizer is not installed, to grant the proper compressor suction feeding during heat recovery operation if present.

8.9 Liquid Injection

Liquid injection is activated when the circuit is in a run state and the discharge temperature rises above the Liquid Injection Activation set point.

Liquid injection is turned off when the discharge temperature decreases below the activation set point by a differential of 10^ C.

Situations may arise that require some action from the chiller or that should be logged for future reference. A condition that requires a shutdown and/or lockout is an alarm. Alarms may cause a normal stop (with pumpdown) or a rapid stop. Most alarms require manual reset, but some reset automatically when the alarm condition is corrected. Other conditions can trigger what is known as an event, which may or may not cause the chiller to respond with a specific action in response. All alarms and events are logged.

9.1 Signaling Alarms

The following actions will signal that an alarm has occurred:

The unit or a circuit will execute a rapid or pumpdown shutoff.

An alarm bell icon ⚙ will be displayed in the upper right-hand corner of all controller screens including the optional remote user interface panel's screens.

An optional field supplied and wired remote alarm device will be activated.

9.2 Clearing Alarms

Active alarms can be cleared through the keypad/display or a BAS network. Alarms are automatically cleared when controller power is cycled. Alarms are cleared only if the conditions required to initiate the alarm no longer exist. All alarms and groups of alarms can be cleared via the keypad or network via LON using nviClearAlarms and via BACnet using the

ClearAlarms object

To use the keypad, follow the Alarm links to the Alarms screen, which will show Active Alarms and Alarm Log. Select Active Alarm and press the wheel to view the Alarm List (list of current active alarms). They are in order of occurrence with the most recent on top. The second line on the screen shows Alm Cnt (number of alarms currently active) and the status of the alarm clear function. Off indicates that the Clear function is off and the alarm is not cleared. Press the wheel to go to the edit mode. The Alm Clr (alarm clear) parameter will be highlighted with OFF showing. To clear all alarms, rotate the wheel to select ON and enter it by pressing the wheel.

An active password is not necessary to clear alarms.

If the problem(s) causing the alarm have been corrected, the alarms will be cleared, disappear from the Active Alarm list and be posted in the Alarm Log. If not corrected, the On will immediately change back to OFF and the unit will remain in the alarm condition.

9.2.1 Remote Alarm Signal

The unit is configured to allow field wiring of a alarm devices.

9.3 Description of Alarms

9.3.1 Phase Volts Loss/GFP Fault

Alarm description (as shown on screen): Unit PVM/GFP Fault

Trigger: PVM set point is set to Single Point and PVM/GFP input is low

Action Taken: Rapid stop all circuits

Reset: Auto reset when PVM input is high or PVM set point does not equal single point for at least 5 seconds.

9.3.2 Evaporator Flow Loss

Alarm description (as shown on screen): Evap Water Flow Loss

Trigger:

1: Evaporator Pump State = Run AND Evaporator Flow Digital Input = No Flow for time > Flow Proof Set Point AND at least one compressor running

2: Evaporator Pump State = Start for time greater than Recirc Timeout Set Point and all pumps have been tried

Action Taken: Rapid stop all circuits

Reset:

This alarm can be cleared at any time manually via the keypad or via the BAS clear alarm signal.

If active via trigger condition 1:

When the alarm occurs due to this trigger, it can auto reset the first two times each day, with the third occurrence being manual reset.

For the auto reset occurrences, the alarm will reset automatically when the evaporator state is Run again. This means the alarm stays active while the unit waits for flow, then it goes through the recirculation process after flow is detected. Once the recirculation is complete, the evaporator goes to the Run state which will clear the alarm. After three occurrences, the count of occurrences is reset and the cycle starts over if the manual reset flow loss alarm is cleared.

If active via trigger condition 2:

If the flow loss alarm has occurred due to this trigger, it is always a manual reset alarm.

9.3.3 Evaporator Water Freeze Protect

Alarm description (as shown on screen): Evap Water Freeze

Trigger: Evaporator LWT or EWT drops below evaporator freeze protect set point. If the sensor fault is active for either LWT or EWT, then that sensor value cannot trigger the alarm.

Action Taken: Rapid stop all circuits

Reset: This alarm can be cleared manually via the keypad or via the BAS clear alarm signal, but only if the alarm trigger conditions no longer exist.

9.3.4 Evaporator #1 Water Freeze Protect

Alarm description (as shown on screen): Evap#1 Water Freeze

Trigger: Evaporator LWT read from Evaporator #1 LWT probe drops below evaporator freeze protect set point AND sensor fault is not active.

Action Taken: Rapid stop of circuits #1 and #2

Reset: This alarm can be cleared manually via the keypad or via the BAS clear alarm signal, but only if the alarm trigger conditions no longer exist.

9.3.5 Evaporator #2 Water Freeze Protect

Alarm description (as shown on screen): Evap#2 Water Freeze

Trigger: Evaporator LWT read from Evaporator #2 LWT probe drops below evaporator freeze protect set point AND sensor fault is not active

Action Taken: Rapid stop of circuits #3 and #4

Reset: This alarm can be cleared manually via the keypad or via the BAS clear alarm signal, but only if the alarm trigger conditions no longer exist.

9.3.6 Evaporator Water Temperatures Inverted

Alarm description (as shown on screen): Evap Water Inverted

Trigger: Evap EWT < Evap LWT - 1 deg C AND at least one circuit is running AND EWT sensor fault not active AND LWT sensor fault not active] for 30 seconds

Action Taken: Pumpdown stop on all circuits

Reset: This alarm can be cleared manually via the keypad.

9.3.7 Leaving Evaporator Water Temperature Sensor Fault

Alarm description (as shown on screen): Evap LWT Sens Fault

Trigger: Sensor shorted or open

Action Taken: Rapid stop all circuits

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.3.8 Leaving Evaporator Water Temperature Sensor Fault #1

Alarm description (as shown on screen): Evap LWT Sens#1 Fault

Trigger: Sensor shorted or open

Action Taken: Rapid stop of circuits 1 and 2

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.3.9 Leaving Evaporator Water Temperature Sensor Fault #2

Alarm description (as shown on screen): Evap LWT Sens#2 Fault

Trigger: Sensor shorted or open

Action Taken: Rapid stop of circuits 3 and 4

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.3.10 AC Comm Failure

Alarm description (as shown on screen): AC Comm. Fail

Trigger: Communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of all running circuits.

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.3.11 Outdoor Air Temperature Sensor Fault

Alarm description (as shown on screen): OAT Sensor Fault

Trigger: Sensor shorted or open and Low Ambient Lockout is enabled.

Action Taken: Normal shutdown of all circuits.

Reset: This alarm can be cleared manually via the keypad if the sensor is back in range or Low Ambient Lockout is disabled.

9.3.12 External Alarm

Alarm description (as shown on screen): External Alarm

Trigger: External Alarm/Event input is open for at least 5 seconds and external fault input is configured as an alarm.

Action Taken: Rapid stop of all circuits.

Reset: Auto clear when digital input is closed.

9.3.13 Emergency Stop Alarm

Alarm description (as shown on screen): Emergency Stop Switch

Trigger: Emergency Stop input is open.

Action Taken: Rapid stop of all circuits.

Reset: This alarm can be cleared manually via the keypad if the switch is closed.

9.4 Unit Events

The following unit events are logged in the event log with a time stamp.

9.4.1 Entering Evaporator Water Temperature Sensor Fault

Event description (as shown on screen): EWT Sensor Fail

Trigger: Sensor shorted or open

Action Taken: Return water reset cannot be used.

Reset: Auto reset when sensor is back in range.

9.4.2 Unit Power Restore

Event description (as shown on screen): Unit Power Restore

Trigger: Unit controller is powered up.

Action Taken: none

Reset: none

9.4.3 External Event

Alarm description (as shown on screen): External Event

Trigger: External Alarm/Event input is open for at least 5 seconds and external fault is configured as an event.

Action Taken: None

Reset: Auto clear when digital input is closed.

9.4.4 Low Ambient Lockout

Alarm description (as shown on screen): Low Ambient Lockout

Trigger: The OAT drops below the low ambient lockout set point and low ambient lockout is enabled.

Action Taken: Normal shutdown of all running circuits.

Reset: The lockout will clear when OAT rises to the lockout set point plus 2.5°C, or when low ambient lockout is disabled.

9.5 Option Alarms

9.5.1 Heat Recovery Water Freeze Protect

Alarm description (as shown on screen): HeatRecFrz

Trigger: Heat Recovery LWT or EWT drops below evaporator freeze protect set point. If the sensor fault is active for either LWT or EWT, then that sensor value cannot trigger the alarm.

Action Taken: Heat Recovery is disabled, the Heat Recovery water pump contact is activated.

Reset: This alarm can be cleared manually via the keypad or via the BAS clear alarm signal, but only if the alarm trigger conditions no longer exist.

9.5.2 Heat Recovery Leaving Water Temperature Sensor Fault

Alarm description (as shown on screen): HeatRecLwtSenf

Trigger: Sensor shorted or open

Action Taken: Heat Recovery is disabled.

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.5.3 Option Comm Failure

Alarm description (as shown on screen): OptionExtFault

Trigger: Communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Heat Recovery is disabled.

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.6 Option Events

9.6.1 Heat Recovery Entering Water Temperature Sensor Fault

Event description (as shown on screen): HeatRecEwtSenf

Trigger: Sensor shorted or open

Action Taken: None.

Reset: Auto reset when sensor is back in range.

9.6.2 Low Heat Recovery Entering Water Temperature Lockout

Alarm description (as shown on screen): HeatRecEwtLow

Trigger: The Heat Recovery EWT drops below the Heat Recovery lockout set point.

Action Taken: None.

Reset: The lockout will clear when Heat Recovery EWT rises to the lockout set point plus 0.5°C.

9.7 Circuit Stop Alarms

All circuit stop alarms require shutdown of the circuit on which they occur. Rapid stop alarms do not do a pumpdown before shutting off. All other alarms will do a pumpdown.

When one or more circuit alarms are active and no unit alarms are active, the alarm output will be switched on and off on 5 second intervals.

Alarm descriptions apply to all circuits, the circuit number is represented by 'N' in the description.

9.7.1 Phase Volts Loss/GFP Fault

Alarm description (as shown on screen): PVM/GFP Fault N

Trigger: PVM input is low and PVM set point = Multi Point

Action Taken: Rapid stop circuits

Reset: Auto reset when PVM input is high or PVM set point does not equal multi point for at least 5 seconds.

9.7.2 Low Evaporator Pressure

Alarm description (as shown on screen): Evap Press Low N

Trigger: [Freezestat trip AND Circuit State = Run] OR Evaporator Press < -70 kPa

Freezestat logic allows the circuit to run for varying times at low pressures. The lower the pressure, the shorter the time the compressor can run. This time is calculated as follows:

Freeze error = Low Evaporator Pressure Unload - Evaporator Pressure

Freeze time = 70 - 6.25 x freeze error, limited to a range of 20-70 seconds

When the evaporator pressure goes below the Low Evaporator Pressure Unload set point, a timer starts. If this timer exceeds the freeze time, then a freezestat trip occurs. If the evaporator pressure rises to the unload set point or higher, and the freeze time has not been exceeded, the timer will reset.

The alarm cannot trigger if the evaporator pressure sensor fault is active.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually if the evaporator pressure is above -69 kPa.

9.7.3 Low Pressure Start Fail

Alarm description (as shown on screen): LowPressStartFail N

Trigger: Circuit state = start for time greater than Startup Time set point.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad

9.7.4 Mechanical Low Pressure Switch

Alarm description (as shown on screen): Mech Low Pressure Sw N

Trigger: Mechanical Low Pressure switch input is low

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad if the MLP switch input is high.

9.7.5 High Condenser Pressure

Alarm description (as shown on screen): Cond Pressure High N

Trigger: Condenser Saturated Temperature > Max Saturated Condenser Value for time > High Cond Delay set point.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad

9.7.6 Low Pressure Ratio

Alarm description (as shown on screen): Low Pressure Ratio N

Trigger: Pressure ratio < calculated limit for a time > Low Pressure Ratio Delay set point after circuit startup has completed.

The calculated limit will vary from 1.4 to 1.8 as the compressor's capacity varies from 25% to 100%.

Action Taken: Normal shutdown of circuit

Reset: alarm can be cleared manually via the Unit Controller keypad

9.7.7 Mechanical High Pressure Switch

Alarm description (as shown on screen): Mech High Pressure Sw N

Trigger: Mechanical High Pressure switch input is low AND Emergency Stop Alarm is not active.

(opening emergency stop switch kills power to MHP switches)

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad if the MHP switch input is high.

9.7.8 High Discharge Temperature

Alarm description (as shown on screen): Disc Temp High N

Trigger: Discharge Temperature > High Discharge Temperature set point AND compressor is running. Alarm cannot trigger if discharge temperature sensor fault is active.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.9 High Oil Pressure Difference

Alarm description (as shown on screen): Oil Pres Diff High N

Trigger: Oil Pressure Differential > High Oil Pressure Differential set point for a time greater than Oil Pressure Differential Delay.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.10 Oil Level Switch

Alarm description (as shown on screen): Oil Level Low N

Trigger: Oil level switch open for a time greater than Oil level switch Delay while compressor is in the Run state.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.11 Compressor Starter Fault

Alarm description (as shown on screen): Starter Fault N

Trigger:

If PVM set point = None(SSS): any time starter fault input is open

If PVM set point = Single Point or Multi Point: compressor has been running for at least 14 seconds and starter fault input is open

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.12 High Motor Temperature

Alarm description (as shown on screen): Motor Temp High

Trigger:

Input value for the motor temperature is 4500 ohms or higher.

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad after input value for motor temperature has been 200 ohms or less for at least 5 minutes.

9.7.13 Low OAT Restart Fault

Alarm description (as shown on screen): LowOATRestart Fail N

Trigger: Circuit has failed three low OAT start attempts

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.14 No Pressure Change After Start

Alarm description (as shown on screen): NoPressChgAtStrt N

Trigger: After start of compressor, at least a 6 kPa drop in evaporator pressure OR 35 kPa increase in condenser pressure has not occurred after 15 seconds

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.15 No Pressure At Startup

Alarm description (as shown on screen): No Press At Start N

Trigger: [Evap Pressure < 35 kPa OR Cond Pressure < 35 kPa] AND Compressor start requested AND circuit does not have a fan VFD

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the Unit Controller keypad.

9.7.16 CC Comm Failure N

Alarm description (as shown on screen): CC Comm. Fail N

Trigger: Communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of affected circuit

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.17 FC Comm Failure Circuit 1/2

Alarm description (as shown on screen): FC Comm Fail Cir 1/2

Trigger: [Circuit 1 or Circuit 2 Number of Fans > 6 OR PVM Config = Multi Point] and communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of circuit 1 and 2

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.18 FC Comm Failure Circuit 3

Alarm description (as shown on screen): FC Comm Fail Cir 3

Trigger: Number of Circuits set point is greater than 2 and communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of circuit 3

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.19 FC Comm Failure Circuit 4

Alarm description (as shown on screen): FC Comm. Fail Cir 4

Trigger: Number of Circuits set point is greater than 3 and communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of circuit 4

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.20 FC Comm Failure Circuit 3/4

Alarm description (as shown on screen): FC Comm. Fail Cir 3/4

Trigger: Circuit 3 or circuit 4 Number of Fans > 6, Number of circuits set point > 2, and and communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module.

Action Taken: Rapid stop of circuit 3 and 4

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.21 EEXV Comm Failure N

Alarm description (as shown on screen): EEXV Comm. Fail N

Trigger: Communication with the I/O extension module has failed. Section 3.1 indicates the expected type of module and the address for each module. Alarm on Circuit #3 will be enabled if Number of Circuits set point > 2; alarm on Circuit #4 will be enabled if Number of Circuits set point > 3.

Action Taken: Rapid stop of affected circuit

Reset: This alarm can be cleared manually via the keypad when communication between main controller and the extension module is working for 5 seconds.

9.7.22 Evaporator Pressure Sensor Fault

Alarm description (as shown on screen): EvapPressSensFault N

Trigger: Sensor shorted or open

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.7.23 Condenser Pressure Sensor Fault

Alarm description (as shown on screen): CondPressSensFault N

Trigger: Sensor shorted or open

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.7.24 Oil Pressure Sensor Fault

Alarm description (as shown on screen): OilPressSensFault N

Trigger: Sensor shorted or open

Action Taken: Normal shutdown of circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.7.25 Suction Temperature Sensor Fault

Alarm description (as shown on screen): SuctTempSensFault N

Trigger: Sensor shorted or open

Action Taken: Normal shutdown of circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.7.26 Discharge Temperature Sensor Fault

Alarm description (as shown on screen): DiscTempSensFault N

Trigger: Sensor shorted or open

Action Taken: Normal shutdown of circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.7.27 Motor Temperature Sensor Fault

Alarm description (as shown on screen): MotorTempSensFault N

Trigger: Sensor shorted or open

Action Taken: Rapid stop circuit

Reset: This alarm can be cleared manually via the keypad, but only if the sensor is back in range.

9.8 Circuit Events

The following events limit operation of the circuit in some way as described in the Action Taken column. The occurrence of a circuit event only affects the circuit on which it occurred. Circuit events are logged in the event log on the unit controller.

9.8.1 Low Evaporator Pressure - Hold

Event description (as shown on screen): EvapPress Low Hold N

Trigger: This event is not enabled until the circuit startup is complete and the unit mode is Cool. Then, while running, if evaporator pressure <= Low Evaporator Pressure Hold set point the event is triggered. The event is not to be triggered for 90 seconds following the capacity change of the compressor from 50% to 60%.

Action Taken: Inhibit loading.

Reset: While still running, the event will be reset if evaporator pressure > (Low Evaporator Pressure Hold SP + 14 kPa). The event is also reset if the unit mode is switched to Ice, or the circuit is no longer in the run state.

9.8.2 Low Evaporator Pressure - Unload

Event description (as shown on screen): EvapPressLowUnload N

Trigger: This event is not enabled until the circuit startup is complete and the unit mode is Cool. Then, while running, if evaporator pressure <= Low Evaporator Pressure Unload set point the event is triggered. The event is not to be triggered for 90 seconds following the capacity change of the compressor from 50% to 60% (for Asymmetric compressors only).

Action Taken: Action Taken: Unload the compressor by decreasing the capacity by one step every 5 seconds until the evaporator pressure rises above the Low Evaporator Pressure Unload set point.

Reset: While still running, the event will be reset if evaporator pressure > (Low Evaporator Pressure Hold SP + 14 kPa). The event is also reset if the unit mode is switched to Ice, or the circuit is no longer in the run state.

9.8.3 High Condenser Pressure - Hold

Event description (as shown on screen): CondPressHigh Hold N

Trigger: While the compressor is running and unit mode is Cool, if saturated condenser temperature >= High Saturated Condenser Hold Value, the event is triggered.

Action Taken: Inhibit loading.

Reset: While still running, the event will be reset if saturated condenser temperature < (High Saturated Condenser Hold Value - 5.5 °C). The event is also reset if the unit mode is switched to Ice, or the circuit is no longer in the run state.

9.8.4 High Condenser Pressure - Unload

Event description (as shown on screen): CondPressHighUnloadN

Trigger: While the compressor is running and unit mode is Cool, if saturated condenser temperature >= High Saturated Condenser Unload Value, the event is triggered.

Action Taken: Unload the compressor by decreasing the capacity by one step every 5 seconds until the evaporator pressure rises above the High Condensing Pressure Unload set point.

Reset: While still running, the event will be reset if saturated condenser temperature < (High Saturated Condenser Unload Value - 5,5 °C). The event is also reset if the unit mode is switched to Ice, or the circuit is no longer in the run state.

9.8.5 Failed Pumpdown

Event description (as shown on screen): Pumpdown Fail Cir N

Trigger: Circuit state = pumpdown for time > Pumpdown Time set point

Action Taken: Shutdown circuit

Reset: N/A

9.8.6 Power Loss While Running

Event description (as shown on screen): Run Power Loss Cir N

Trigger: Circuit controller is powered up after losing power while compressor was running

Action Taken: N/A

Reset: N/A

9.9 Alarm Logging

When an alarm occurs, the alarm type, date, and time are stored in the active alarm buffer corresponding to that alarm (viewed on the Alarm Active screens) also in the alarm history buffer (viewed on the Alarm Log screens). The active alarm buffers hold a record of all current alarms.

A separate alarm log stores the last 25 alarms to occur. When an alarm occurs, it is put into the first slot in the alarm log and all others are moved down one, dropping the last alarm. In the alarm log, the date and time the alarm occurred are stored, as well as a list of other parameters. These parameters include unit state, OAT, LWT, and EWT for all alarms. If the alarm is a circuit alarm, then the circuit state, refrigerant pressures and temperatures, EXV position, compressor load, number of fans on, and compressor run time are also stored.

10.1 The Unit Controller Operation

Figure 6, Unit Controller

TCP/IP Port

Menu Button Back Button Alarm Button Navigation Wheel Display

The keypad/display consists of a 5-line by 22 character display, three buttons (keys) and a "push and roll" navigation wheel. There is an Alarm Button, Menu (Home) Button, and a Back Button. The wheel is used to navigate between lines on a screen (page) and to increase and decrease changeable values when editing. Pushing the wheel acts as an Enter Button and will jump from a link to the next set of parameters.

Figure 7, Typical Screen

◆6 View/Set Unit 3 Status/Settings > Set Up > Temperature > Date/Time/Schedule >

Generally, each line contains a menu title, a parameter (such as a value or a setpoint), or a link (which will have an arrow in the right of the line) to a further menu.

The first line visible on each display includes the menu title and the line number to which the cursor is currently "pointing", in the above case 3. The left most position of the title line includes an "up" arrow to indicate there are lines (parameters) "above" the currently displayed line; and/or a "down" arrow to indicate there are lines (parameters) "below" the currently displayed items or an "up/down" arrow to indicate there are lines "above and below" the currently displayed line. The selected line is highlighted.

Each line on a page can contain status only information or include changeable data fields (setpoints). When a line contains status only information and the cursor is on that line, all but the value field of that line is highlighted, meaning the text is white with a black box around it. When the line contains a changeable value and the cursor is at that line, the entire line is highlighted.

Or a line in a menu may be a link to further menus. This is often referred to as a jump line, meaning pushing the navigation wheel will cause a "jump" to a new menu. An arrow (>)is displayed to the far right of the line to indicate it is a "jump" line and the entire line is highlighted when the cursor is on that line.

NOTE - Only menus and items that are applicable to the specific unit configuration are displayed.

This manual includes information relative to the operator level of parameters; data and setpoints necessary for the every day operation of the chiller. There are more extensive menus available for the use of service technicians.

10.2 Navigating

When power is applied to the control circuit, the controller screen will be active and display the Home screen, which can also be accessed by pressing the Menu Button. The navigating wheel is the only navigating device necessary, although the MENU, ALARM, and BACK buttons can provide shortcuts as explained later.

10.2.1 Passwords

The home screen has eleven lines:

- Enter Password, links to the Entry screen, which is an editable screen. So pressing the wheel goes to the edit mode where the password (5321) can be entered. The first (*) will be highlighted, rotate the wheel clockwise to the first number and set it by pressing the wheel. Repeat for the remaining three numbers.

The password will time out after 10 minutes and is cancelled if a new password is entered or the control powers down.

- Other basic information and links are shown on the Main Menu page for ease of usage and includes Active setpoint, Evaporator Leaving Water Temperature, etc. The About Chiller link connect to a page were is possible to see the software version.

Figure 8, Password Menu

	Main Menu 1/11
Enter Password > Unit Status= Auto Active Setpt= xx.x°C Evap LWT= xx.x°C Unit Capacity= xxx.x% Unit Mode= Cool Time Until Restart > Alarms > Scheduled Maintenance > About Chiller >

Figure 9, Password Entry Page

	Enter Password 1/1
Enter ****

Entering an invalid password has the same effect as continuing without a password.

Once a valid password has been entered, the controller allows further changes and access without requiring the user to enter a password until either the password timer expires or a different password is entered. The default value for this password timer is 10 minutes. It is changeable from 3 to 30 minutes via the Timer Settings menu in the Extended Menus.

10.2.2 Navigation Mode

When the navigation wheel is turned clockwise, the cursor moves to the next line (down) on the page. When the wheel is turned counter-clockwise the cursor moves to the previous line (up) on the page. The faster the wheel is turned the faster the cursor moves. Pushing the wheel acts as an "Enter" button.

Three types of lines exist:

• Menu title, displayed in the first line as in Figure 9
• Link (also called Jump) having an arrow (> ) in the right of the line and used to link to the next menu.
• Parameters with a value or adjustable setpoint.

For example, "Time Until Restart" jumps from level 1 to level 2 and stops there.

When the Back Button is pressed the display reverts back to the previously displayed page. If the Back button is repeated pressed the display continues to revert one page back along the current navigation path until the "main menu" is reached. When the Menu (Home) Button is pressed the display reverts to the "main page."

When the Alarm Button is depressed, the Alarm Lists menu is displayed.

10.2.3 Edit Mode

The Editing Mode is entered by pressing the navigation wheel while the cursor is pointing to a line containing an editable field. Once in the edit mode pressing the wheel again causes the editable field to be highlighted. Turning the wheel clockwise while the editable field is highlighted causes the value to be increased. Turning the wheel counter-clockwise while the editable field is highlighted causes the value to be decreased. The faster the wheel is turned the faster the value is increased or decreased. Pressing the wheel again cause the new value to be saved and the keypad/display to leave the edit mode and return to the navigation mode.

A parameter with an "R" is read only; it is giving a value or description of a condition. An "R/W indicates a read and/or write opportunity; a value can be read or changed (providing the proper password has been entered).

Example 1: Check Status, for example -is the unit being controlled locally or by an external network? We are looking for the Unit Control Source Since this a unit status parameter, start at Main Menu and select View/Set Unit and press the wheel to jump to the next set of menus. There will be an arrow at the right side of the box, indicating that a jump to the next level is required. Press the wheel to execute the jump.

You will arrive at the Status/ Settings link. There is an arrow indicating that this line is a link to a further menu. Press the wheel again to jump to the next menu, Unit Status/Settings.

Rotate the wheel to scroll down to Control Source and read the result.

Example 2; Change a Set point, the chilled water set point for example. This parameter is designated as Cool LWT Set point 1 and is a unit set parameter. From the Main Menu select View/Set Unit. The arrow indicated that this is link to a further menu.

Press the wheel and jump to the next menu View/Set Unit and use the wheel to scroll down to Temperatures. This again has an arrow and is a link to a further menu. Press the wheel and jump to the Temperatures menu, which contains six lines of temperatures set points. Scroll down to Cool LWT 1 and press the wheel to jump to the item change page. Rotate the wheel to adjust the set point to the desired value. When this is done press the wheel again to confirm the new value. With the Back button it will be possible to jump back to the Temperatures menu where the new value will be displayed.

Example 3; Clear an Alarm,. The presence of a new alarm is indicated with a Bell ringing on the top right of the display. If the Bell is frozen one or more alarm had been acknowledged but are still active. To view the Alarm menu from the Main Menu scroll down to the Alarms line or simply press the Alarm button on the display. Note the arrow indicating this line is a link. Press the wheel to jump to the next menu Alarms There are two lines here; Alarm Active and Alarm Log. Alarms are cleared from the Active Alarm link. Press the wheel to jump to the next screen. When the Active Alarm list is entered scroll to the item AlmClr which is set to off by default. Change this value to on to acknowledge the alarms. If the alarms can be cleared then the alarm counter will display 0 otherwise it will display the number of alarm still active. When the alarms are acknowledged the Bell on the top right of the display will stop to ring if some of the alarms are still active or will disappear if all the alarms are cleared.

Figure 10, Home Page, Main Menu Parameters and Links

graph TD
    A["Home Page"] --> B["Main Menu"]
    C["Enter Password\nContinue W/O Password"] --> B
    B --> D["View/Set - Unit"]
    B --> E["View/Set - Circuit"]
    B --> F["Unit Status *"]
    B --> G["Active Setpoint *"]
    B --> H["Evap Leaving Water Temp *"]
    B --> I["Evap Entering Water Temp *"]
    B --> J["Unit Capacity *"]
    B --> K["Unit Current"]
    B --> L["Softload Limit Value"]
    B --> M["Network Limit Value"]
    B --> N["Demand Limit Value"]
    B --> O["Unit Mode *"]
    B --> P["Control Source *"]
    B --> Q["Current Limit Setpoint"]
    B --> R["Time Until Restart"]
    B --> S["Scheduled Maintenance"]
    B --> T["Alarms"]
    B --> U["About This Chiller"]

    V["View/Set Unit"] --> W["View/Set IP Setup"]
    V --> X["BACnet MSTP Setup"]
    V --> Y["Modbus Setup"]
    V --> Z["AWM Setup"]
    V --> AA["Design Conditions"]
    V --> AB["Alarm Limits"]
    V --> AC["Menu Password"]

    AD["View/Set Circuit"] --> AE["View/Set 1 Cycle Time Remaining *"]
    AD --> AF["Compressor 1 Cycle Time Remaining *"]
    AD --> AG["Compressor 2 Cycle Time Remaining *"]
    AD --> AH["Compressor 3 Cycle Time Remaining *"]
    AD --> AI["Compressor 4 Cycle Time Remaining *"]

    AJ["Time Until Restart"] --> AK["Alarms"]
    AJ --> AL["Alarm Log"]

    AM["Scheduled Maintenance"] --> AN["Next Maintenance Month/Year *"]
    AM --> AO["Service Support Reference *"]

    AP["About This Chiller"] --> AQ["Model Number *"]
    AP --> AR["G. O. Number *"]
    AP --> AS["Unit Serial Number *"]
    AP --> AT["Starter Model Number(s) *"]
    AP --> AU["Starter Serial Number(s) *"]
    AP --> AV["Firmware Version *"]
    AP --> AW["Application Version *"]
    AP --> AX["Application GUID *"]
    AP --> AY["HMI GUID *"]

Note: Parameters with an “*” are available without entering a password.

Figure 11, Navigation, Part A

graph TD
    A["View/Set Unit"] --> B["Status/Settings (view/set unit)"]
    A --> C["Set-Up"]
    A --> D["Temperatures"]
    A --> E["Date/Time/Schedules"]
    A --> F["Power Conservation"]
    A --> G["LON Setup"]
    A --> H["BACnet IP Setup"]
    A --> I["BACnet MSTP Setup"]
    A --> J["Modbus Setup"]
    A --> K["AWM Setup"]
    A --> L["Design Conditions"]
    A --> M["Alarm Limits"]
    A --> N["Menu Password"]

    B --> O["Unit Status R"]
    B --> P["Chiller Enable R"]
    B --> Q["Control Source R"]
    B --> R["Next Circuit On R"]
    B --> S["Chiller Enable Setpoint - Network R"]
    B --> T["Chiller Mode Setpoint - Network R"]
    B --> U["Cool Setpoint - Network R"]
    B --> V["Capacity Limit Setpoint - Network R"]
    B --> W["Stage Up Delay Remaining R"]
    B --> X["Stage Down Delay Remaining R"]
    B --> Y["Clear Stage Delays R/W"]
    B --> Z["Ice Setpoint - Network R"]
    B --> AA["Ice Cycle Time Remaining R"]
    B --> AB["Evaporator Pump 1 Run Hours R"]
    B --> AC["Evaporator Pump 2 Run Hours R"]
    B --> AD["Remote Service Enable R/W"]

    C --> AE["View/Set Circuit >"]
    C --> AF["Status/Settings >"]
    C --> AG["Compressor >"]

    AE --> AH["Set-Up (view/set unit)"]
    AF --> AH
    AG --> AH
    AH --> AI["Available Modes R"]
    AH --> AJ["Start Up DT R"]
    AH --> AK["Shut Down DT R"]
    AH --> AL["Stage Up DT R"]
    AH --> AM["Stage Down DT R"]
    AH --> AN["Max Pulldown Rate R"]
    AH --> AO["Stage Up Delay R"]
    AH --> AP["Chiller Status After Power Failure R"]
    AH --> AQ["Ice Cycle Delay R"]

    AE --> AR["Time Until Restart"]
    AE --> AS["Compressor 1 Cycle Time Remaining R"]
    AE --> AT["Compressor 2 Cycle Time Remaining R"]
    AE --> AU["Compressor 3 Cycle Time Remaining R"]
    AE --> AV["Compressor 4 Cycle Time Remaining R"]

    AR --> AW["Temperatures (view/set unit)"]
    AR --> AX["Evap Leaving Water Temp R"]
    AR --> AY["Evap Entering Water Temp R"]
    AR --> AZ["Evaporator Delta T R"]
    AR --> BA["Active Set Point R"]
    AR --> BB["Outside Air Temperature R"]
    AR --> BC["Cool LWT Setpoint 1 R/W"]
    AR --> BD["Cool LWT Setpoint 2 R/W"]
    AR --> BE["Ice LWT Setpoint R/W"]

    AS --> BF["Scheduled Maintenance"]
    AS --> BG["Next Maintenance Month/Year R/W"]
    AS --> BH["Service Support Reference R"]

    AF --> BI["About This Chiller"]
    AF --> BJ["Model Number R"]
    AF --> BK["G. O. Number R"]
    AF --> BL["Unit Serial Number R"]
    AF --> BM["Starter Model Number(s) R"]
    AF --> BN["Starter Serial Number(s) R"]
    AF --> BO["Firmware Version R"]
    AF --> BP["Application Version R"]
    AF --> BQ["Application GUID R"]
    AF --> BR["HMI GUID R"]
    AF --> BS["OBH GUID R"]

    BI --> BT["Date/Time/Schedules (view/set unit)"]

    style A fill:#f9f,stroke:#333
    style B fill:#ccf,stroke:#333
    style C fill:#cfc,stroke:#333
    style AD fill:#fcc,stroke:#333

Note: Parameters with an “*” are available without entering a password.

Figure 12, Navigation, Part B

View/Set Unit
Status/Settinos	>
Set-Up	>
Temperatures	>
Date/Time/Schedules	>
Power Conservation	>
LON Setup	>
BACnet IP Setup	>
BACnet MSTP Setup	>
Modbus Setup	>
AWM Setup	>
Design Conditions	>
Alarm Limits	>
Menu Password	>
View/Set Circuit	>
Status/Settinos	>
Compressor	>

Time Until Restart	>
Compressor 1 Cycle Time Remaining	R
Compressor 2 Cycle Time Remaining	R
Compressor 3 Cycle Time Remaining	R
Compressor 4 Cycle Time Remaining	R

Alarms	>
Alarm Active	>
Alarm Log	>

Scheduled Maintenance
Next Maintenance Month/Year	R/W
Service Support Reference	R

About This Chiller
Model Number	R
G. O. Number	R
Unit Serial Number	R
Starter Model Number(s)	R
Starter Serial Number(s)	R
Firmware Version	R
Application Version	R
Application GUID	R
HMI GUID	R
OBH GUID	R

Power Conservation (view/set unit)
Unit Capacity	R
Unit Current	R
Demand Limit Enable	R/W
Demand Limit Value	R
Current @ 20mA	R
Current Limit Setpoint	R
Setpoint Reset	R/W
Max Reset	R/W
Start Reset DT	R/W
Max Reset OAT	R/W
Start Reset OAT	R/W
Soft Load Enable	R/W
Soft Load Ramp	R/W
Starting Capacity	R/W

LON Setup (view/set unit)
Neuron ID	R
Max Send Time	R/W
Min Send Time	R/W
Receive Heartbeat	R/W
LON BSP	R
LON App Version	R

BACnet IP Setup (view/set unit)
Apply Changes	R/W
Name	R/W
Dev Instance	R/W
UDP Port	R/W
DHCP	R/W
Actual IP Address	R
Actual Mask	R
Actual Gateway	R
Given IP Address	R/W
Given Mask	R/W
Given Gateway	R/W
Unit Support	R/W
NC Dev 1	R/W
NC Dev 2	R/W
NC Dev 3	R/W
BACnet BSP	R

BACnet MSTP Setup (view/set unit)
Apply Changes	R/W
Name	R/W
Dev Instance	R/W
MSTP Address	R/W
Baud Rate	R/W
Max Master	R/W
Max Info Frm	R/W
Unit Support	R/W
Term Resistor	R/W
NC Dev 1	R/W
NC Dev 2	R/W
NC Dev 3	R/W
BACnet BSP	R

Modbus Setup (view/set unit)
Apply Changes	R/W
Address	R/W
Parity	R/W
Two Stop Bits	R/W
Baud Rate	R/W
Load Resistor	R/W
Response Delay	R/W
Comm LED Time Out	R/W

graph TD
    A["View/Set Unit"] --> B["AWM Setup (view/set unit)"]
    A --> C["Design Conditions (view/set unit)"]
    A --> D["Alarm Limits (view/set unit)"]
    A --> E["Menu Password"]
    A --> F["View/Set Circuit"]
    A --> G["Status/Settings"]
    A --> H["Compressor"]
    A --> I["Time Until Restart"]
    A --> J["Alarms"]
    A --> K["Scheduled Maintenance"]
    A --> L["About This Chiller"]

    B --> M["AWMT Setup (view/set unit)"]
    B --> N["Design Conditions (view/set unit)"]
    B --> O["Menu Password (view/set unit)"]

    C --> P["Applv Changes R/W"]
    C --> Q["DHCP R/W"]
    C --> R["Actual IP Address R"]
    C --> S["Actual Mask R"]
    C --> T["Actual Gateway R"]
    C --> U["Given IP Address R/W"]
    C --> V["Given Mask R/W"]
    C --> W["Given Gateway R/W"]
    C --> X["AWM BSP R"]

    D --> Y["Evap Entering Water Temp @ Design R"]
    D --> Z["Evap Leaving Water Temp @ Design R"]

    E --> AA["Low Pressure Hold Setpoint R"]
    E --> AB["Low Pressure Unload Setpoint R"]

    F --> AC["Password Disable R/W"]

    G --> AD["Status/Settings (view/set circuit)"]
    G --> AE["Circuit Status R"]
    G --> AF["Circuit Mode R/W"]
    G --> AG["Circuit Capacity R"]

    H --> AH["Compressor (view/set circuit)"]
    H --> AI["Compressor 1 Circuit 1"]

    I --> AJ["Run Hours R"]
    I --> AK["Number Of Starts R"]

    J --> AL["Alarm Active (Alarms)"]
    J --> AM["Alarm Log (Alarms)"]

    K --> AN["Model Number R"]
    K --> AO["G.O. Number R"]
    K --> AP["Unit Serial Number R"]
    K --> AQ["Starter Model Number(s) R"]
    K --> AR["Starter Serial Number(s) R"]
    K --> AS["Firmware Version R"]
    K --> AT["Application Version R"]
    K --> AU["Application GUID R"]
    K --> AV["HMI GUID R"]
    K --> AW["OBH GUID R"]

Note: Parameters with an “*” are available without entering a password.

The optional remote user interface is a remote control panel that mimics operation of the controller located on the unit. Up to eight AWS units can be connected to it and selected on the screen. It provides HMI (Human Machine Interface) within a building, the building engineer's office for example, without going outdoors to the unit.

It can be ordered with the unit and shipped loose as a field installed option. It can also be ordered anytime after chiller shipment and mounted and wired on the job as explained on the following page. The remote panel is powered from the unit and no additional power supply is required.

All viewing and setpoint adjustments available on the unit controller are available on the remote panel. Navigation is identical to the unit controller as described in this manual.

The initial screen when the remote is turned on shows the units connected to it. Highlight the desired unit and press the wheel to access it. The remote will automatically show the units attached to it, no initial entry is required.

Menu Button Main Index 2/6 Password enter > INTP > Communication > Global functions > Alarm handling > System overview > Back Button Push and Roll Navigating Wheel Alarm Button w/Flashing Red Alarm Light

Technical Specifications

interface

Process Item	Up to right interface per minute
Bus connector		CE2, CE3, not interchargeable
Terminal	Inter Cameroon
Max length	700 m
Onlin type	Tested pair color, 0.5 - 2.5 mm
Display
LCD type	FUTN
Dimensions	5.70 x 3.0 x 1.5 D inches (140 x 59 x 35 mm)
Exclusion	Exclamide 50 x 200 pixels
Backlight	Blue or white, non-configuration
Environmental Conditions
Operator	IEC 721-3-3
Temperature	48 to 70 °C
Restriction LCD		-20 to 60 °C
Frequency	<30% vs. no continuous
Air pollutants	Min. 200 kPa, corresponding to min. 2,000 mL/minute at least

Cover Removal

Process Bus Wiring Connections

graph LR
    A["8-bit Serial Interface"] --> B["8-bit 8-bit"]
    B --> C["8-bit 8-bit 8-bit"]
    C --> D["8-bit 8-bit 8-bit"]
    D --> E["8-bit 8-bit 8-bit"]
    E --> F["8-bit 8-bit 8-bit"]
    F --> G["8-bit 8-bit 8-bit"]
    G --> H["8-bit 8-bit 8-bit"]
    H --> I["8-bit 8-bit 8-bit"]
    I --> J["8-bit 8-bit 8-bit"]
    J --> K["8-bit 8-bit 8-bit"]
    K --> L["8-bit 8-bit 8-bit"]
    L --> M["8-bit 8-bit 8-bit"]
    M --> N["8-bit 8-bit 8-bit"]
    N --> O["8-bit 8-bit 8-bit"]
    O --> P["8-bit 8-bit 8-bit"]
    P --> Q["8-bit 8-bit 8-bit"]
    Q --> R["8-bit 8-bit 8-bit"]
    R --> S["8-bit 8-bit 8-bit"]
    S --> T["8-bit 8-bit 8-bit"]
    T --> U["8-bit 8-bit 8-bit"]
    U --> V["8-bit 8-bit 8-bit"]
    V --> W["8-bit 8-bit 8-bit"]
    W --> X["8-bit 8-bit 8-bit"]
    X --> Y["8-bit 8-bit 8-bit"]
    Y --> Z["8-bit 8-bit 8-bit"]
    Z --> AA["8-bit 8-bit 8-bit"]
    AA --> AB["8-bit 8-bit 8-bit"]
    AB --> AC["8-bit 8-bit 8-bit"]
    AC --> AD["8-bit 8-bit 8-bit"]
    AD --> AE["8-bit 8-bit 8-bit"]
    AE --> AF["8-bit 8-bit 8-bit"]
    AF --> AG["8-bit 8-bit 8-bit"]
    AG --> AH["8-bit 8-bit 8-bit"]
    AH --> AI["8-bit 8-bit 8-bit"]
    AI --> AJ["8-bit 8-bit 8-bit"]
    AJ --> AK["8-bit 8-bit 8-bit"]
    AK --> AL["8-bit 8-bit 8-bit"]
    AL --> AM["8-bit 8-bit 8-bit"]
    AM --> AN["8-bit 8-bit 8-bit"]
    AN --> AO["8-bit 8-bit 8-bit"]
    AO --> AP["8-bit 8-bit 8-bit"]
    AP --> AQ["8-bit 8-bit 8-bit"]
    AQ --> AR["8-bit 8-bit 8-bit"]
    AR --> AS["8-bit 8-bit 8-bit"]
    AS --> AT["8-bit 8-bit 8-bit"]
    AT --> AU["8-bit 8-bit 8-bit"]
    AU --> AV["8-bit 8-bit 8-bit"]
    AV --> AW["8-bit 8-bit 8-bit"]
    AW --> AX["8-bit 8-bit 8-bit"]
    AX --> AY["12-bit Serial Interface"]
    style A fill:#f9f,stroke:#333
    style B fill:#f9f,stroke:#333
    style C fill:#f9f,stroke:#333
    style D fill:#f9f,stroke:#333
    style E fill:#f9f,stroke:#333
    style F fill:#f9f,stroke:#333
    style G fill:#f9f,stroke:#333
    style H fill:#f9f,stroke:#333
    style I fill:#f9f,stroke:#333
    style AJ fill:#f9f,stroke:#333
    style AK fill:#f9f,stroke:#333
    style AL fill:#f9f,stroke:#333
    style AM fill:#f9f,stroke:#333
    style AN fill:#f9f,stroke:#333
    style AO fill:#f9f,stroke:#333
    style AP fill:#f9f,stroke:#333
    style AQ fill:#f9f,stroke:#333
    style AR fill:#f9f,stroke:#333

Remote Interface C.E- and CE- Terminals Unit Interface

Through the wall wiring connection Surface wiring connection

11.1 Embedded Web Interface

The Microtech 4 controller has an embedded web interface that can be used to monitor the unit when connected to a local network. It is possible to configure the IP addressing of the Microtech 4 as a fixed IP of DHCP depending on the network configuration.

With a common web browser a PC can connect with the unit controller entering the IP address of the controller or the host name, both visible in the "About Chiller" page accessible without entering a password.

When connected, it will be required to enter a user name and a password. Enter the following credential to get access to the web interface:

User Name: ADMIN

Password: SBTAdmin!

The Main Menu page will be displayed. The page is a copy of the onboard HMI and follows the same rules in terms of access levels and structure.

Main Menu Enter Password View/Set Unit View/Set Circuit Unit Status Off: Unit Switch Setpoint 7.0°C Evaporator LWT 7.0°C Unit Capacity 0.0%

Sleep trending Setpoint Evaporator EWT Online trend 08-18-45 08-18-50 08-18-51 08-19-01 08-19-10 08-19-15 08-19-20 08-19-25 08-19-30 08-19-31 Date

In addition it allows to trend log a maximum of 5 different quantities. It's required to click on the value of the quantity to monitor and the following additional screen will become visible:

Depending on the web browser and its version the trend log feature may not be visible. It's required a web browser supporting HTML 5 like for example:

• Microsoft Internet Explorer v.11,
- Google Chrome v.37,
- Mozilla Firefox v.32.

These software are only an example of the browser supported and the versions indicated have to be intended as minimum versions.

NOTICE

Daikin service personnel or factory authorized service agency must perform initial start-up in order to activate warranty.

CAUTION

Most relays and terminals in the unit control center are powered when S1 is closed and the control circuit disconnect is on. Therefore, do not close S1 until ready for start-up or the unit may start unintentionally and possibly cause equipment damage.

12.1.1 Seasonal Start-up

1. Double check that the discharge shutoff valve and the optional compressor suction butterfly valves are open.
2. Check that the manual liquid-line shutoff valves at the outlet of the subcooler coils and the oil separator oil return line shutoff valves are open.
3. Check the leaving chilled water temperature setpoint on the MicroTech controller to be sure it is set at the desired chilled water temperature.
4. Start the auxiliary equipment for the installation by turning on the time clock, and/or remote on/off switch, and chilled water pump.
5. Check to see that pumpdown switches Q1 and Q2 (and Q3) are in the "Pumpdown and Stop" (open) position. Throw the S1 switch to the "auto" position.
6. Under the "Control Mode" menu of the keypad, place the unit into the automatic cool mode.
7. Start the system by moving pumpdown switch Q1 to the "auto" position.
8. Repeat step 7 for Q2 (and Q3).

Microtech controller, extension modules and communication modules are equipped with two status LED (BSP and BUS) to indicate the operational status of the devices. The meaning of the two status LED is indicated below.

Controller LED

BSP LED	BUS LED	Mode
Solid Green	OFF	Application running
Solid Yellow	OFF	Application loaded but not running (*)
Solid Red	OFF	Hardware Error (*)
Flashing Yellow	OFF	Application not loaded (*)
Flashing Red	OFF	BSP Error (*)
Flashing Red/Green	OFF	Application/BSP update

(*) Contact Service.

Extension Module LED

BSP LED	BUS LED	Mode
Solid Green		BSP running
Solid Red		Hardware Error (*)
Flashing Red		BSP Error (*)
	Solid Green	Communication running, I/O working
	Solid Yellow	Communication running, parameter missing (*)
	Solid Red	Communication down (*)

(*) Contact Service.

Communication Module LED

BSP LED	Mode
Solid Green	BPS running, communication with controller
Solid Yellow	BSP running, no communication with controller (*)
Solid Red	Hardware Error (*)
Flashing Red	BSP Error (*)
Flashing Red/Green	Application/BSP update

(*) Contact Service.

BUS LED status vary depending on the module.

LON module:

BuS LED	Mode
Solid Green	Ready for Communication. (All Parameter loaded, Neuron configured). Doesn't indicate a communication with other devices.
Solid Yellow	Startup
Solid Red	No Communication to Neuron (internal error, could be solved by downloading a new LON application)
Flashing Yellow	Communication not possible to the Neuron. The Neuron must be configured and set online over the LON Tool.

Bacnet MSTP:

BuS LED	Mode
Solid Green	Ready for Communication. The BACnet Server is started. It doesn't indicate a active communication
Solid Yellow	Startup
Solid Red	BACnet Server down. Automatically a restart after 3 seconds are initiated.

Bacnet IP:

BuS LED	Mode
Solid Green	Ready for Communication. The BACnet Server is started. It doesn't indicate a active communication
Solid Yellow	Startup. The LED stays yellow until the module receives a IP Address, therefore a link must be established.
Solid Red	BACnet Server down. Automatic restart after 3 seconds is initiated.

Modbus

BuS LED	Mode
Solid Green	All Communication running
Solid Yellow	Startup, or one configured channel not communicating to the Master.
Solid Red	All configured Communications down. Means no communication to the Master. The timeout can be configured. In case that the timeout is zero the timeout is disabled.

14 Controller maintenance

The controller requires to maintain the installed battery. Every two years it's required to replace the battery. Battery model is: BR2032 and it is produced by many different vendors.

To replace the battery remove the plastic cover of the controller display using a screw driver as shown in the following picture:

Two-panel photo showing a device with control knobs and a hand inserting a screwdriver to its side (no visible text or symbols)

Be careful to avoid damages to the plastic cover. The new battery shall be placed in the proper battery holder which is highlighted in the following picture, respecting the polarities indicated into the holder itself.

Close-up of a white electronic device with a metallic connector and green screen, placed on a metal panel (no visible text or symbols)

Air cooled screw chillers could be equipped with the Freecooling option to reduce the amount of refrigerant cooling when the ambient temperature is low.

The control architecture in this case requires an additional extension module indicated with the label HR and address The I/O map for this module is:

Channel	Type	Function	Range
X3	NTC	Freecooling coils antifreeze sensor (future use)
X5	V	Freecooling valve position feedback	0-10V
X7	DI	Freecooling Enable Switch
X8	AO	Freecooling Three Way Valve	0-10V
DO3	DO	Freecooling Butterfly Valves
DO4	DO	Freecooling Pump (Glycol Free only)

Two possible types of logics will be available depending on the unit selection:

• Freecooling Priority
- Condensing Priority

15.1 Freecooling Priority

This option requires the installation of additional equipment to control the condensation during freecooling operation, in particular a pressostatic valve to control the refrigerant level in the condenser coils. During freecooling operation fans are kept running at maximum speed whenever the ambient temperature is cold enough. In order to allow a proper compressor operation and to keep condensation high enough with cold air the condenser coils area is reduced flooding part of the coils, this allows a condensing pressure high enough to avoid alarms.

15.2 Condensing Priority

In this case if refrigerant cooling is needed the fan control is released to condensing temperature control of the circuit. In order to increase the freecooling effect the condensing target is reduced during refrigerant cooling to maximize the cold air effect. The control will take care to guarantee the minimum pressure ratio needed for proper chiller operations.

Set Up of the Freecooling function

The Freecooling function must be enabled through the controller. In the page: View/Set Unit → Configuration the setpoint: Freecool Inst: Yes/No

is used to enable the freecooling additional setpoints and functionalities, when this is done a controller reboot is required.

Freecooling operations

When all the conditions are verified the Freecooling valve switch to enable, the air cooled freecooling coils and the main pump are started. The logic will wait for flow presence before fans can be started so in case of low flow freecooling will not start and the flow alarm will be generated without any potential impact on the unit safety (freezing due to low flow and cold air forced through the coils).

The valve requires 2.5 minutes to go from fully closed to fully open so fans operation will start only after this time has elapsed.

When freecooling operations are started the fans will run. Number of fans and fans speed will depend on the water temperature and on the combined action of refrigerant cooling.

Whenever a compressor will be running and the freecooling conditions verified, fans will run at maximum possible speed.

This speed will depend on the type of freecooling, Freecooling or Condensing priority, in the first maximum will mean all fans on and VFD at "FC Max VFD sp"; in the second the condensing target will be calculated in order to ensure the minimum pressure ratio.

The present publication is drawn up by of information only and does not constitute an offer binding upon Daikin Applied Europe S.p.A.. Daikin Applied Europe S.p.A. has compiled the content of this publication to the best of its knowledge. No express or implied warranty is given for the completeness, accuracy, reliability or fitness for particular purpose of its content, and the products and services presented therein. Specification are subject to change without prior notice. Refer to the data communicated at the time of the order. Daikin Applied Europe S.p.A. explicitly rejects any liability for any direct or indirect damage, in the broadest sense, arising from or related to the use and/or interpretation of this publication. All content is copyrighted by Daikin Applied Europe S.p.A..