Checking The Inverter Board Error Detection Circuit; Checking The Inverter For Damage At No-Load - Mitsubishi Electric PUHY-HP72 Service Handbook

[8-9 Troubleshooting Inverter Problems ]
8-9-2

Checking the Inverter Board Error Detection Circuit

Items to be checked
(1) Stop the unit.
Remove power supply.
(2) Disconnect the inverter
output wires from the
compressor terminals (U,
*1
V, W).
(3) Apply power supply.
(4) Put the outdoor unit into
operation.
*1 Output voltage is present at the inverter output wiring terminal. To avoid short-circuiting and ground fault, do not let the
terminal come in contact with the unit or the compressor, and use caution not to damage the terminal.
8-9-3 Checking the Compressor for Ground Fault and Coil Resistance Problems
Items to be checked
Disconnect the compressor wir-
ing, and check the compressor
Meg, and coil resistance.
8-9-4

Checking the Inverter for Damage at No-Load

Items to be checked
(1) Stop the unit.
Remove power supply.
(2) Disconnect the inverter
output wires from the
compressor terminals (U,
*1
V, W).
(3) Set SW7-1 on the MAIN
board to ON.
(4) Apply power supply.
(5) Put the outdoor unit into
operation.
Check the inverter output
voltage after the inverter
output frequency has sta-
bilized.
*1 Output voltage is present at the inverter output wiring terminal. To avoid short-circuiting and ground fault, do not let the
terminal come in contact with the unit or the compressor, and use caution not to damage the terminal.
HWE18240_GB
Phenomena
1) Overcurrent error
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
Phenomena
1) Compressor Meg failure
Error if less than 1 M .
2) Compressor coil resistance failure
Coil resistance value
HP72 model
0.078 (YNU), 0.192
HP96, 120 models
0.087 (YNU), 0.219
Phenomena
1) Inverter-related problems are detected.
2) Inverter voltage is not output at the termi-
nals (U, V, and W)
3) There is an voltage imbalance between
the wires.
Greater than 5% imbalance or 5V
4) There is no voltage imbalance between
the wires.
Replace the INV board.
Replace the INV board.
Replace the INV board.
Normal
Check that there is no liquid refrigerant
in the compressor.
If there is none, replace the compres-
sor.
Replace the compressor.
(TNU)
(TNU)
Set SW7-1 on the MAIN board to ON,
and go to [8-9-2 Checking the Inverter
Board Error Detection Circuit].
Replace the INV board.
Replace the INV board.
Normal
*When done checking, set SW7-1 on
the MAIN board back to as it was.
Remedy
Remedy
Remedy
33
chapter 8 -