CM 2 - Multimeter BENNING - Free user manual and instructions

USER MANUAL CM 2 BENNING

(IEC LR03/ “Micro”).

Operating Manual BENNING CM 2 TRUE RMS Digital Current Clamp Multimeter for - alternating-current measurement - AC-voltage measurement - DC-current measurement - resistance measurement - continuity testing Contents:

3. Scope of delivery

4. Description of unit

8. Measuring with the BENNING CM 2

10. Technical data of the measuring accessories

This Operating Manual is intended for: - qualified electricians, competent persons and - electrotechnically trained persons. The BENNING CM 2 is designed for measurements in dry surroundings and must not be used in circuits with rated voltages higher than 600 V (for more details, see section 6 “Ambient conditions”). The following symbols are used in the Operating Manual and on the BENNING CM 2 itself: Application around and removal from HAZARDOUS LIVE conductors is permitted.

This symbol indicates an electrical hazard.

This symbol indicates sources of danger when using the BENNING CM 2 (see documentation). This symbol on the BENNING CM 2 indicates that the unit is protection insulated (safety class II). This symbol appears in the display for a discharged battery This symbol indicates the continuity-testing application. The buzzer provides an audible signal. DC-voltage or current AC-current or voltage

Earth (voltage to earth) Note After unmark the adhesive label „Warnung...“ (on battery compartment lid) the English text appears.03/ 2019 BENNING CM 2

The instrument is built and tested in accordance with DIN VDE 0411 part 1/ EN 61010-1 DIN VDE 0411 part 2-032/ EN 61010-2-032 DIN VDE 0411 part 2-033/ EN 61010-2-033 DIN VDE 0411 part 031/ EN 61010-031 and has left the factory in perfectly safe technical condition. To maintain this condition and ensure safe operation of the multimeter, the user must observe the notes and warnings given in these instructions at all times. Improper handling and non-observance of the warnings might involve severe injuries or danger to life.

WARNING! Be extremely careful when working with bare conductors or main line carrier! Contact with live conductors will cause an electric shock!

The unit may be used only in power circuits within the over- voltage category II with a conductor for 600 V max. to earth, or within overvoltage category III with a conductor for 300 V against ground. Only use suitable measuring leads for this. With measurements within measurement category III, the projecting conductive part of a contact tip of the measuring leads must not be longer than 4 mm. Prior to carrying out measurements within measurement cat- egory III, the push-on caps provided with the set and marked with CAT III and CAT IV must be pushed onto the contact tips. The purpose of this measure is user protection. Remember that work on electrical components of all kinds is dangerous. Even low voltages of 30 V AC and 60 V DC may be dangerous to human life.

Before starting the multimeter up, always check it as well as all cables and wires for signs of damage. Should it appear that safe operation of the multimeter is no longer possible, it should be shut down immediately and secured to prevent it being switched on accidentally. It may be assumed that safe operation is no longer possible: - if the instrument or the measuring leads show visible signs of damage, or - if the multimeter no longer functions, or - after long periods of storage under unfavourable conditions, or - after being subjected to rough transport, - if the device or the measuring lead are exposed to moisture.

In order to avoid danger, - do not touch the bare prod tips of the measuring leads, - insert the measurement leads in the appropriately desig- nated measuring sockets on the multimeter

3. Scope of delivery

The following items make up the standard BENNING CM 2 package:

3.1 One digital multimeter

3.2 One safety measuring leads (black)(L = 1.4 m)

3.3 One safety measuring leads (red)(L = 1.4 m)

3.4 One compact protection case

3.5 Two 1.5 V micro-batteries (installed in the multimeter when supplied)

3.6 One Operating Manual

Note on consumable parts:

The BENNING CM 2 is supplied by two 1.5 V micro-batteries (2 x 1.5 V IEC LR 03) - The above mentioned safety leads (tested spare part (no. 044145)) are approved in accordance with CAT III 1000 V and for a current up 10 A.

4. Description of tester unit

The BENNING CM 2 is a digital current clamp multimeter with a measuring head fitted with a Hall sensor. See fig. 1: Front panel03/ 2019 BENNING CM 2

The display and operating elements shown in fig. 1 are as follows: Housing Sliding switch for selecting the required functions. - OFF - AC-voltage measurement (AC) and DC-voltage measurement (DC) These functions alternate when the function button marked with AC/DC is pressed. The digital display indicates the current function. - AC-current measurement (AC) and DC-current measurement (DC) These functions alternate when the function button marked with AC/DC is pressed. The digital display indicates the current function. - Resistance measurement and continuity measurement with buzzer These functions alternate when the function button marked with / is pressed. The digital display indicates the current function. Digital display (liquid-crystal type) with following indications: - measurement reading with max. indication 3999 - polarity indication - decimal point - symbol for discharged battery - type of voltage selected (AC or DC voltage) - type of current selected (AC or DC current) - the measurement value retained (hold function) or the automatically retained peak measurement value (MAX function) - the measurement function selected by indication of the extended/non- extended measurement units of current and resistance - selected continuity test with buzzer. Function button AC/DC - / . The digital display shows “DC”, “AC”,

- Forselection between measurement of DC voltage/current or AC voltage/ current or - Resistance measurement and continuity test. HOLD/MAX button (hold function and automatic peak-value storage) - The first press of the button causes the currently indicated measurement value to be held (indicated by “HOLD” in the digital display , no updating of measurement value). - The second press of the button leads to continuous measurement. - Pressing the button (for 2 sec.) during switch-on initiates the peak-value storage (MAX) function. A second press of the button does not lead to continuous measurement. - The first press of the button causes the peak value during the switched-on measuring time to be stored (indicated by “MAX” in the digital display ). For all ranges except continuity test. Switch back (continuous measure- ment) by pressing MAX button (2 sec.). - The function is switched off by pressing the OFF button. ZERO button (zero setting button) for zero adjustment in current measure- ment. Can also be used for all ranges for differential measurement (zero setting possible for any value). Indicated by “REL” in the digital display. COM socket: joint socket for voltage and resistance measurements and continuity test, marked black

Ω socket (positive): joint socket for voltage and resistance measure- ments and continuity test, marked red Opening lever, for opening and closing the current prongs Prong guard, protects user from accidental contact with conductor Measurement prongs, for inserting and gripping the single conductor containing AC current.

5.1.1 The digital display is designed as a 3 3/4 digit liquid-crystal indicator with 13

mm digit height and decimal point. The highest value displayed is 3999.

5.1.2 The polarity indication functions automatically. Contrary to the

measurement-wire definition, only one pole is indicated as “-”.

5.1.3 The range overload will be displayed with "OL" or "-OL" and sometimes

with an acoustic signal. Attention: no display or warning by complete overload.

5.1.4 The nominal measuring rate of the digital display of the BENNING CM

2 is approx. 2 measurements per second.

5.1.5 The BENNING CM 2 switches off automatically after approx. 30 minutes.

It can only be switched on again by means of the switch. The buzzer sounds to signal that the unit has switched off automatically.

5.1.6 Temperature coefficient of measurement value for voltage and resistance

measurements: 0.15 x (stated measurement accuracy) °C < 18 °C or > 28 °C with reference to the value at the reference temperature of 23 °C.

5.1.7 Temperature coefficient of measurement value for current measurements:03/ 2019

0.2 x (stated measurement accuracy) °C < 20 °C or > 26 °C with refer-

ence to the value at the reference temperature of 23 °C.

5.1.8 The BENNING CM 2 is supplied by 2 1.5 V batteries (IEC LR03/ ”Micro”).

5.1.9 When the battery voltage drops under the intended operating voltage of

the BENNING CM 2, a battery symbol appears in the display.

5.1.10 The service life of the battery is approx. 60 hours (alkali battery).

5.1.11 Dimensions of unit (length x width x height) = 192 x 66 x 27 mm.

Weight of unit: 205 g

5.1.12 The safety measuring leads and measurement tips supplied are spe-

cially suited to the rated voltage of the BENNING CM 2. The measuring tips can be protected by caps.

5.1.13 Widest prong opening: 25 mm

- The BENNING CM 2 is designed only for measuring in dry surroundings. - Maximum barometric height during measurement: 2000 m - Overvoltage category / set-up category: IEC 60664-1/ IEC 61010-1 → 300 V category III, 600 V category II, - Degree of contamination: 2 - Protection Class: IP 30 (DIN VDE 0470-1 IEC/ EN 60529) IP 30 means: Protection against access to dangerous parts and protection against solid impurities of a diameter > 2.5 mm, (3 - first index). No protec- tion against water, (0 - second index). - Operating temperature and relative humidity for voltage and resistance measurements: At operating temperature of 0 °C to 30 °C: relative humidity under 80% At operating temperature of 30 °C to 40 °C: relative humidity under 75% At operating temperature of 40 °C to 50 °C: relative humidity under 45% - Operating temperature and relative humidity for current measurements: At operating temperature of 0 °C to 30 °C: relative humidity under 80% At operating temperature of 30 °C to 40 °C: relative humidity under 75% - The BENNING CM 2 can be stored at temperatures from - 20 °C to + 60 °C. The batteries must be removed from the unit.

Note: The measurement accuracy is stated as the sum of - a relative proportion of the measurement value and - a number of digits (i.e. numerical steps of the last place). This measurement accuracy applies for a temperature of 23 °C ± 5 °C (23 °C ± 3 °C for current measurement) and a maximum relative humidity of 80%. The BENNING CM 2 has an automatic switch-over of measurement range. Previous setting is therefore not required.

The input resistance is ≥ 10 MΩ parallel 100 pF. The measuring value is gained and indicated as effective value (True RMS, AC coupling). Its calibration is adapted for a sinusoidal curve form. With deviations from this form, the display value becomes less accurate. The additional error for the following crest factors is as follows: crest factor of 1.4 to 2.0: additional error ± 1.0% crest factor of 2.0 to 2.5: additional error ± 2.5% crest factor of 2.5 to 3.0: additional error ± 4.0%03/ 2019 BENNING CM 2

• When input is opened, fluctuating up to 30 digits; measuring range ≥ 1 mV

maximum start-up time until display appears, 20 sec.

No-load voltage approx. 3 V, max. test current 0.1 mA The built-in buzzer sounds when resistance is less than 50 Ω - 300 Ω.

7.5 DC current ranges

Measurement accuracy at a temperature of 23 °C ± 3 °C Measuring range Resolution Measurement accuracy Overload protection

Measurement accuracy at a temperature of 23 °C ± 3 °C. The measuring value is gained and indicated as effective value (True RMS, AC coupling). Its calibra- tion is adapted for a sinusoidal curve form. With deviations from this form, the display value becomes less accurate. The additional error for the following crest factors is as follows: crest factor of 1.4 to 2.0: additional error ± 1.0% crest factor of 2.0 to 2.5: additional error ± 2.5% crest factor of 2.5 to 3.0: additional error ± 4.0% Measuring range Resolution Measurement accuracy Overload protection

± (2.0 % of reading + 5 digit)* for frequencies 50 - 60 Hz ± (3.0 % of reading + 7 digit)* for frequencies 40 - 1 kHz 400 A

± (2.5 % of reading + 3 digit) for frequencies 50 Hz - 60 Hz ± (3.5 % of reading + 5 digit) for frequencies 40 Hz - 1 kHz 400 A

200.0 - 300.0 A 100 mA

± (4.0 % of reading + 3 digit) for frequencies 50 Hz - 60 Hz ± (6.0 % of reading + 5 digit) for frequencies 40 Hz - 1 kHz 400 A

The measuring accuracy of the MAX-Hold display is the stated measuring accu- racy in % + 10 digits for the next measuring range. When passing to the measur- ing range after next, the error increases to + 20 digits etc. (Example: starting figure 100 mV - 120 V = + 30 digits). When measuring resistance, a MAX hold indication is only possible in the range from 400 to 400 k.

8. Measuring with the BENNING CM 2

8.1 Preparation for measuring

Store and use the BENNING CM 2 only under the correct temperature condi- tions stated. Always avoid longer exposure to sunlight. - Check the rated voltage and current stated on the safety measuring leads with tips. The rated voltage and current of the safety measuring leads and tips comply with the BENNING CM 2. - Check the insulation of the measuring leads and tips. If the insulation is damaged, replace the safety measuring leads immediately. - Check the continuity of the safety measuring leads. If the leads is discon- nected at any point, remove it immediately. - Before selecting another function with the sliding switch or the function button , the safety measuring leads and tips must be disconnected from the measuring point. - Strong sources of interference close to the BENNING CM 2 may produce unstable readings and measurement errors.

8.2 Voltage measurement

Always observe the maximum voltage to earth potential! Electrical hazard! The maximum voltage which may be applied to the sockets - COM socket, black , - V- socket (positive) for voltage and resistance measurements and continuity testing (marked red) of the BENNING CM 2 against ground, amounts to 600 V. - Select the desired function with the sliding switch and the function button of the BENNING CM 2. - Contact the black safety measuring lead with the COM-socket (black). - Contact the red safety measuring lead with the V- socket (red). - Bring the black and red measuring tips into contact with the measurement points. Read the measured value on the digital display . Note:

In small voltage measuring ranges, the zero-volt indication does not appear (due to interference) when the safety measuring leads are open. Make sure that the BENNING CM 2 is fully functional by short-circuiting the measuring tips. See fig. 2: DC-voltage measurement See fig. 3: AC-voltage measurement

8.3 Resistance measurement

- Select the desired function with the sliding switch and the function button of the BENNING CM 2. - Contact the black safety measuring lead with the COM-socket (black). - Contact the red safety measuring lead with the V- socket (red). - Bring the black and red measuring tips into contact with the measurement points. Read the measured value on the digital display . Note: - To obtain a correct measurement, ensure that no voltage is applied to the measuring point. - With small resistances, the measuring result can be improved by measuring the resistance of the safety measuring leads beforehand by short-circuiting the measuring tips and subtracting the reading obtained from the resistance measured.03/ 2019 BENNING CM 2

8.4 Continuity testing with buzzer

- Select the area marked with the buzzer symbol with the sliding switch and the function button of the BENNING CM 2. - Contact the black safety measuring lead with the COM-socket (black). - Contact the red safety measuring lead with the V- socket (red). - Bring the black and red measuring tips into contact with the measurement points. If the resistance between the measurement points is less than 50 , the buzzer incorporated in the BENNING CM 2 sounds. See fig. 5: Continuity testing with buzzer

8.5 Current measurement

8.5.1 Preparation for measurement

Store and use the BENNING CM 2 only under the correct temperature condi- tions stated. Always avoid long exposure to sunlight. - Strong sources of interference close to the BENNING CM 2 may produce unstable readings and measurement errors.

Do not apply voltage to the output contacts of the BENNING CM 2. If necessary, remove the safety measuring leads connected. When measuring DC current, observe correct polarity.

8.5.2 Current measurement

- Select the desired measuring function with the sliding switch and the function button . - Press the “ZERO” button to set the BENNING CM 2 to the starting point. - Operate the opening lever . Grip the single wire containing the current to be measured with the prongs of the BENNING CM 2. - Read the value in the digital display . See fig. 6: AC/ DC current measurement

Before opening the BENNING CM 2, ensure that it is not connected to a source of voltage! Electrical hazard! Any work required on the BENNING CM 2 when it is under voltage must be done only by a qualified electrician. Special steps must be taken to pre- vent accidents. Before opening the BENNING CM 2, remove it from all sources of voltage as follows: - Remove first the black and the red measuring tip from the measurement object. - Then remove the black and red safety measuring leads from the BENNING CM 2. - Move the sliding switch to the position “OFF”.

9.1 Making the unit safe

Under certain circumstances, the safety of the BENNING CM 2 can no longer be guaranteed. This may be the case if: - there are visible signs of damage on the unit, - errors occur in measurements, - the unit has been stored for a long period of time under the wrong condi- tions, and - if the unit has been subjected to rough handling during transport. In these cases, the BENNING CM 2 must be switched off immediately, removed from the measuring points and secured to prevent it from being used again.

Clean the outside of the unit with a clean dry cloth. (Exception: any type of special cleaning cloth). Never use solvents or abrasives to clean the clamp meter. Ensure that the battery compartment and the battery contacts have not been contaminated by electrolyte leakage. If any electrolyte or white deposits are seen in the battery compartment or battery housing, remove these with a dry cloth.

9.3 Battery replacement

Before opening the BENNING CM 2, ensure that it is not connected to a source of voltage! Electrical hazard! The BENNING CM 2 is powered by two 1.5 V batteries. The batteries must be replaced (see fig. 8) when the battery symbol appears in the display .03/ 2019 BENNING CM 2

To replace the batteries, proceed as follows: - Remove the black and red measuring tips from the measurement circuit. - Remove the black and red safety measuring leads from the BENNING CM 2. - Lay the BENNING CM 2 on its front and unscrew the screw on the cover of the battery compartment. - Push the cover of the battery compartment to the side out of its guide. - Remove the discharged batteries from the battery holder. - Insert the new batteries into the battery holder. Make sure that they are connected to the correct battery poles. - Push the cover of the battery compartment into its correct position and replace the screw. See fig. 7: Replacing the batteries.

Remember the environment! Do not dispose of used batteries with domestic waste. Dispose of them at a battery-collection point or as toxic waste. Your local authority will give you the information you need.

Benning guarantees compliance with the technical and accuracy specifications stated in the operating manual for the first 12 months after the delivery date. To maintain the specified precision of the measurement results, the instrument must be recalibrated at regular intervals by our factory service. We recommend a recalibration interval of one year. Send the appliance to the following address: Benning Elektrotechnik & Elektronik GmbH & CO. KG Service Centre Robert-Bosch-Str. 20 D - 46397 Bocholt

10. Technical data of the measuring accessories

- Standard: EN 61010-031, - Maximum rated voltage to earth (

) and measuring category: With push-on caps: 1000 V CAT III, 600 V CAT IV, Without push-on caps: 1000 V CAT II, - Maximum rated current: 10 A, - Protective class II (

), continuous double or reinforced insulation, - Contamination class: 2, - Length: 1.4 m, AWG 18, - Environmental conditions: Maximum barometric elevation for making measurements: 2000 m, Temperatures: 0 °C to + 50 °C, humidity 50 % to 80 % - Only use the test leads if in perfect condition and according to this manual, since the protection provided could otherwise be impaired. - Throw the test leads out if the insulation is damaged or if there is a break in the cable/ plug. - Do not touch the bare contact tips of the test leads. Only grab the area appropriate for hands! - Insert the angled terminals in the testing or measuring device.

11. Environmental note

At the end of the product’s useful life, please dispose of the device at collection points provided in your community.03/ 2019 BENNING CM 2