Solutions For The Main Earth Leakage Breaker Trip - Mitsubishi Electric PUHY-HP72 Service Handbook

[8-9 Troubleshooting Inverter Problems ]
8-9-12

Solutions for the Main Earth Leakage Breaker Trip

Items to be checked
[1] Check the earth leakage breaker
capacity and the sensitivity cur-
rent.
[2] Check the resistance at the power
supply terminal block TB1 with a
megger.
[3] Disconnect the compressor wir-
ings and check the resistance of
the compressor with a megger.
[4] Disconnect the fan motor wirings
and check the resistance of the fan
motor with a megger.
Earth leakage current measurement method
For easy on-site measurement of the earth leakage current, enable the filter with a measurement instrument that has filter
functions as below, clamp all the power supply wires, and measure.
Recommended measurement instrument: CLAMP ON LEAK HiTESTER 3283 made by HIOKI E.E. CORPORATION
When measuring one device alone, measure near the device's power supply terminal block.
38
- chapter 8
Phenomena
Use of a non-specified earth
leakage breaker
Failure resistance value
Failure compressor if the insu-
lating resistance value is not in
specified range.
Failure when the insulating re-
sistance value is 1 M or less.
Failure fan motor if the insulat-
ing resistance value is not in
specified range.
Failure when the insulating re-
sistance value is 1 M or less.
Remedy
Replace with a regulation earth leakage
breaker.
Check each part and wiring.
Refer to the following page(s). [8-9-13 Sim-
ple Check on Inverter Circuit Components]
IGBT module
Rush current protection resistor
Electromagnetic relay
DC reactor
Check that there is no liquid refrigerant in
the compressor. If there is none, replace
the compressor.
Replace the fan motor.
HWE18240_GB