Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 355

[ IX Troubleshooting ]
(2) Inverter output related troubles
Items to be checked
[1] (1) Remove power sup-
Check the ply.
INV board er-
ror detection
circuit.
(2) Disconnect the invert-
er output wire from
the terminals of the
INV board (SC-U,
SC-V, SC-W).
(3) Apply power supply.
(4) Put the heat source
unit into operation.
[2] Disconnect the compressor
Check for wiring, and check the com-
compressor pressor Meg, and coil resis-
ground fault tance.
or coil error.
[3] (1) Remove power sup-
Check wheth- ply.
er the inverter
(2) Disconnect the invert-
is damaged.
er output wire from
(No load)
the terminals of the
INV board (SC-U,
SC-V, SC-W).
(3) Disconnect the short-
circuit connector from
CN6 on the INV
board.
(4) Apply power supply.
(5) Put the heat source
unit into operation.
Check the inverter
output voltage after
the inverter output
frequency has stabi-
lized.
HWE15150
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
1) Compressor Meg failure
Error if less than 1 Mohm.
2) Compressor coil resistance failure
<P72, P96, P120 models>
Coil resistance value of 0.71 ohm
<P144, P168, P192 models>
Coil resistance value of 0.30 ohm
1) Inverter-related problems are de-
tected.
2) Inverter voltage is not output at the
terminals (SC-U, SC-V, and SC-W)
3) There is an voltage imbalance be-
tween the wires.
Greater than 5% imbalance or 5V
4) There is no voltage imbalance be-
tween the wires.
- 346 -
Remedy
Replace the INV board.
Replace the INV board.
Replace the INV board.
Normal
Check that there is no liquid re-
frigerant in the compressor.
If there is none, replace the com-
pressor.
Replace the compressor.
Connect the short-circuit connec-
tor to CN6, and go to section [1].
Replace the INV board.
Replace the INV board.
Normal
*Reconnect the short-circuit con-
nector to CN6 after checking the
voltage.
GB