AVTM 55-Jd - Measurement Megger - Free user manual and instructions

Product Type	Digital Multimeter
Brand	Megger
Model	AVTM 55-Jd
Category	Measurement
Dimensions	Approximately 180 x 85 x 45 mm
Weight	About 350 g (including batteries)
Power Supply	2 x AA batteries (1.5 V)
Display	LCD, 4000 counts
Functions	AC/DC voltage, DC current, resistance, continuity, diode test
Safety Rating	CAT III 600 V, CAT II 1000 V
Included Accessories	Test leads, batteries, user manual
Operating Temperature	0°C to 40°C
Storage Temperature	-10°C to 50°C
Auto Power Off	Yes, after 15 minutes
Data Hold	Yes
Overrange Indication	OL displayed
Low Battery Indication	Battery symbol
Cleaning	Wipe with a dry cloth; no solvents
Storage	Keep in dry place at room temperature

Frequently Asked Questions - AVTM 55-Jd Megger

How do I measure AC voltage with the AVTM 55-Jd?

Set the rotary switch to AC V. Connect the black test lead to COM and red to VΩ. Touch probes to the circuit. Read the value on the display.

How do I measure resistance?

Turn off power to the circuit. Set the switch to Ω. Connect leads as for voltage. Touch probes across the resistor. Read resistance.

How do I perform a continuity test?

Set the switch to the continuity (diode) position. Connect leads. If resistance is < 50Ω, the buzzer sounds.

How do I replace the batteries?

Remove the battery cover on the back. Replace with two AA batteries observing polarity. Reattach cover.

What does 'OL' on the display mean?

OL stands for Overload. It indicates the measured value exceeds the range. Select a higher range if possible.

Can I measure current with this meter?

Yes, for DC current up to 10A. Set switch to A. Connect red lead to A (10A max) or mA jack. Break circuit and connect meter in series.

What safety precautions should I follow?

Always use correct range and leads. Do not measure voltage above 600V CAT III. Remove leads from circuit before changing function.

How do I clean the meter?

Use a dry cloth to wipe the casing. Do not use solvents or water. Keep terminals clean.

Does the meter have an auto power-off feature?

Yes, it turns off automatically after 15 minutes of inactivity to save batteries.

What is the accuracy of the AVTM 55-Jd?

Typical accuracy is ±0.5% for DC voltage and ±1.2% for AC voltage. Refer to manual for full specifications.

USER MANUAL AVTM 55-Jd Megger

Single-phase, Hand-cranked TTR® Transformer Turns Ratio Test Set

Black and white photo of a TTR (treatment) device with labeled buttons and wiring, no visible text or symbols on the device body.

■ Used for testing single phase power and distribution transformers
■ Design based on precision bridge measuring technique
■ Unmatched accuracy (±0.1%) in a portable design

DESCRIPTION

The Single-phase TTR ^® Transformer Turns Ratio Test Set measures the turns ratio and exciting current of windings in power, potential and current transformers. Deviations in turns ratio readings indicate problems in one or both windings or the magnetic core circuit.

The TTR test set aids in identifying:

■ Shorted coils
Open circuits
■ Incorrect connections
■ Internal faults or tap-changer defects in step regulators as well as in transformers.

The single-phase, hand-cranked model measures highly sensitive turns ratios of up to 129.99:1 with accuracy of ± 0.1% . An optional auxiliary transformer extends the ratio range to 329.99:1.

The TTR set operates on the principle that the voltage ratio of the transformer at no load is practically equal to the true turns ratio.

The major source of error in a transformer is a primary impedance drop due to magnetizing current, which is kept to a minimum by excitation at a fraction of rated voltage. By employing a design that meets both of these conditions along with the use of a null balance system, the turns ratio of a transformer can be determined accurately.

When measuring the turns ratio of distribution and power transformers, the accuracy is well within 0.1%.

APPLICATIONS

The single phase model is primarily used for testing single-phase power and distribution transformers, for low-ratio readings up to 129.99:1, or up to 329.99:1 with an auxiliary transformer. It can be used to test three-phase transformers by connecting and testing each phase separately.

FEATURES AND BENEFITS

■ Provides unmatched accuracy (±0.1%) in a portable design.
■ Packaged in a rugged, compact case.
■ Measures highly sensitive turn ratios up to 129.99:1. An optional auxiliary transformer extends this ratio range to 329.99:1.

SPECIFICATIONS

Output

8 V, 50/60 Hz

Metering

Four decade dials

Turns Ratio Range

0.001 to 129.999

Exciting Current

0 to 1 A (divide by 5 switch for increased resolution)

Accuracy

±0.1%

Dimensions

7.5 H x 14 W x 12 D in. (189 H x 353 W x 302 D mm)

Weight

16 lb (7.3 kg)

OPTIONAL ACCESSORIES

Auxiliary Transformer

An auxiliary transformer extends the ratio range of single-phase models to 329.99:1. Turns ratio is 100:1 and 200:1, and is accurate to within ± 0.1% .

The auxiliary transformer includes all the necessary cables for connection to the TTR set and the transformer under test.

Dimensions

8 H x 13 W x 10 D in. (203 H x 330 W x 254 D mm)

Weight

13 lb (5.9 kg)

TRS1PLUS

The TRS1PLUS is a unit designed to be used with ratio meters as a high accuracy reference ratio standard. This unique standard is able to provide ratios in both step down (traditional ratio test instruments) and step up (Hand-crank TTR) test modes. The standard is designed for use as a laboratory calibration standard, or as a portable check standard for field ratio and phase verification of any ratio instrument.

Dimensions

5.7 H x 12 W x 10.6 D in. (144 H x 304 W x 270 D mm)

Weight

11 lb (5 kg)

ORDERING INFORMATION

Item (Qty) Cat. No.

Single-phase, Hand-cranked TTR 550005B

Included Accessories

Cable assembly 19494

With C-clamps for X (low-voltage) winding, 10 ft (3 m) [2]

With spring clips for H (high-voltage) winding, 13 ft (4 m) [2]

All cables are permanently connected to the test set.

Instruction manual AVTM55JD

Optional Accessories

Auxiliary transformer 550030

Step down plus step up ratio standard TRS1PLUS