Checking The Inverter Board Error Detection Circuit; Checking The Compressor For Ground Fault And Coil Resistance Problems - Mitsubishi Electric R410A Service Handbook

[8-9 Troubleshooting Inverter Problems (TLMU) ]
8-9-2

Checking the Inverter Board Error Detection Circuit

Items to be checked
<P72, P96, P120, P144 models>
(1) Remove power supply.
(2) Disconnect the inverter out-
put wire from the terminals
of the INV board (SC-U,
SC-V, SC-W).
(3) Apply power supply.
(4) Put the outdoor unit into op-
eration.
<P168 model>
(1) Remove power supply.
(2) Disconnect the inverter out-
put wire from the output ter-
minals (U, V, W) of the IPM.
(3) Apply power supply.
(4) Put the outdoor unit into op-
eration.
8-9-3

Checking the Compressor for Ground Fault and Coil Resistance Problems

Items to be checked
Disconnect the compressor
wiring, and check the compres-
sor Meg, and coil resistance.
HWE14080
Phenomena
1) IPM/overcurrent breaker trip
Error code: 4250
Detail code: No. 101, 104, 105, 106,
and 107
2) Logic error
Error code: 4220
Detail code: No. 111
3) ACCT sensor circuit failure
Error code: 5301
Detail code: No.117
4) IPM open
Error code: 5301
Detail code: No.119
1) IPM/overcurrent breaker trip
Error code: 4250
Detail code: No. 101, 103, 104, 105,
106, and 107
2) Logic error
Error code: 4220
Detail code: No. 111
3) ACCT sensor circuit failure
Error code: 5301
Detail code: No.117
4) DCCT sensor circuit failure
Error code: 5301
Detail code: No.118
5) IPM open
Error code: 5301
Detail code: No.119
Phenomena
1) Compressor Meg failure
Error if less than 1 Mohm.
When no liquid refrigerant in the compres-
sor
2) Compressor coil resistance failure
Coil resistance value of 0.20 ohm (20°C
[68°F]) : P72 model
Coil resistance value of 0.092 ohm (20°C
[68°F]) : P96 - P144 models
- 266 -
Remedy
Replace the INV board.
Replace the INV board.
Replace the INV board.
Normal
Refer to the following page(s).[8-9-14
Troubleshooting Problems with Intelli-
gent Power Module](page 273)
Replace the IPM, and put the outdoor
unit back into operation.
If the problem persists, replace the INV
board.
Refer to the following page(s).[8-9-14
Troubleshooting Problems with Intelli-
gent Power Module](page 273)
Replace the IPM, and put the outdoor
unit back into operation.
If the problem persists, replace the INV
board.
Replace the INV board, and put the out-
door unit back into operation.
If the problem persists, replace the
DCCT.
Replace the INV board.
Replace the DCCT board.
Replace the DCCT, and put the outdoor
unit back into operation.
If the problem persists, replace the INV
board.
Normal
Remedy
Replace the compressor
Check that no liquid refrigerant in the
compressor.
GB