Mitsubishi P120 User Manual

Page of 334
IX  Troubleshooting ] 
- 263 -
HWE09120
GB
(2)  Inverter output related troubles
Items to be checked
Phenomena
Remedy
[1]
Check the 
INV board er-
ror detection 
circuit.
(1)
Disconnect the invert-
er output wire from 
the terminals of the 
INV board (SC-U, 
SC-V, SC-W). 
1)
Overcurrent error 
Error code: 4250
Detail code: No. 101, 104, 105, 
106, and 107
Replace the INV board.
(2)
Put the outdoor unit 
into operation.
2)
Logic error
Error code: 4220
Detail code: No. 111
Replace the INV board.
3)
ACCT sensor circuit failure 
Error code: 5301
Detail code: No.117
Replace the INV board.
4)
IPM open 
Error code: 5301
Detail code: No.119
Normal
[2]
Check for 
compressor 
ground fault 
or coil error.
Disconnect the compressor 
wiring, and check the com-
pressor Meg, and coil resis-
tance.
1)
Compressor Meg failure
Error if less than 1 Mohm.
Check that there is no liquid re-
frigerant in the compressor. 
If there is none, replace the com-
pressor.
2)
Compressor coil resistance failure
Coil resistance value of 0.71 ohm
 (20°C [68°F]): P72 model
Coil resistance value of 0.32 ohm
(20°C [68°F]): P96 - P144 models
Replace the compressor.
[3]
Check wheth-
er the inverter 
is damaged.
(No load)
(1)
Disconnect the invert-
er output wire from 
the terminals of the 
INV board (SC-U, 
SC-V, SC-W).
1)
Inverter-related problems are de-
tected.
Connect the short-circuit connec-
tor to CN6, and go to section [1].
(2)
Disconnect the short-
circuit connector from 
CN6 on the INV 
board.
2)
Inverter voltage is not output at the 
terminals (SC-U, SC-V, and SC-W)
Replace the INV board.
(3)
Put the outdoor unit 
into operation.
Check the inverter 
output voltage after 
the inverter output 
frequency has stabi-
lized.
3)
There is an voltage imbalance be-
tween the wires. 
Greater than 5% imbalance or 5V
Replace the INV board.
4)
There is no voltage imbalance be-
tween the wires.
Normal
*Reconnect the short-circuit con-
nector to CN6 after checking the 
voltage.
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