Test items and methods for transformer fault inspection - Database & Sql Blog Articles

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Shunuo varistor / ESD varistor / product complete / Sunlord first-class agent

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

Photocoupler

test results

cause of issue

Inspection Method

Insulation resistance measurement (with 1000-2500 volts megohmmeter) Coil-coil Coil-ground

Insulation resistance is zero

There is a piercing between the coil and the ground or between the coil and the coil.

Disintegration check coil and insulation

Insulation resistance between coils and between each phase is not equal

May be casing damage

Check the insulation resistance of each phase lead to ground

No-load test

No-load loss and current value are very large

The iron core screw or the iron yoke screw has a short circuit with the iron core, and the grounding piece is improperly assembled to form a short circuit;

Check the grounding condition and the short circuit between the turns. Use a 1000 volt megger to measure the insulation resistance of the iron screw and check the insulation condition of the clamp. When the phase is short-circuited, measure PAC/PAB=PAC4PBC≦25%. If this does not match, That means there is a short circuit between turns

Very no-load loss

Poor insulation between iron chips

Using DC voltage, current method, measuring the insulation resistance of the film between the films

Large no-load current

Insufficient amount of silicon steel sheet for poor iron core joint assembly

Observe the iron core joint and measure the core cross section

Short circuit test

High impedance voltage

Poor connection

Sectional measurement of DC resistance

Short circuit loss is too large

There is a break in the parallel wire, the transposition is incorrect; the wire cross section is less

Short-circuit the low voltage. When the high-voltage Y is connected, apply pressure on the AB, BC, and CA lines respectively, and perform three short-circuit tests. Compare and compare the results of each measurement. When the high-voltage â–³ wiring, short-circuit one phase separately.

Coil connection group measurement

The result is not consistent with any of the connection groups

One coil in a phase coil has the opposite direction

Use the connection group measurement method to find the wrong part of the coil