Mitsubishi Electric PQHY-P200YLM-A Service Handbook page 383

[ IX Troubleshooting ]
(2) Inverter output related troubles
Items to be checked
[1] (1) Turn off the power.
Check the
INV board er-
ror detection
(2)
Disconnect the inverter
circuit.
output wire from the ter-
minals of the INV board
(SC-U, SC-V, SC-W).
(3) Turn on the power.
(4) Put the heat source
unit into operation.
[2] Disconnect the compres-
Check for sor wiring, and check the
compressor compressor Meg, and coil
ground fault resistance.
or coil error.
[3] (1) Turn off the power.
Check wheth-
er the inverter
is damaged.
(2) Disconnect the invert-
(No load)
er output wire from
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) Turn on the power.
(5) Put the heat source unit
into operation.
Check the inverter out-
put voltage after the in-
verter output frequency
has stabilized.
[4] Put the heat source unit
Check wheth- into operation.
er the inverter Check the inverter output
is damaged. voltage after the inverter
(During com- output frequency has stabi-
pressor oper- lized.
ation)
HWE15060
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
<P200, P250, P300 models>
Coil resistance value of 0.71 ohm
<P350, P400, P450, P500 models>
Coil resistance value of 0.30 ohm
<P550, P600 models>
Coil resistance value of 0.611 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.
1) An overcurrent error is detected im-
mediately after the compressor is
started up or during operation.
Error code: 4250
Detail code: No.101, 106, 107
2) There is an voltage imbalance between
the wires.
Greater than 5% imbalance or 5V
- 374 -
Remedy
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 compressor.
Replace the compressor.
Connect the short-circuit connector to CN6,
and go to section [1].
Replace the INV board.
Replace the INV board.
Normal
*Reconnect the short-circuit connector to
CN6 after checking the voltage.
a) Check items [1] through [3] for prob-
lems.
b) Check that high and low pressures are
balanced.
c)
Check for compressor flooding and re-
frigerant flood back.
->If the problem persists after restarting
the unit several times, see item "d "
d)
Check that there is a pressure differ-
ence between high and low pressures
after compressor startup.
->Check the high pressure with LED
monitor for changes. Replace the com-
pressor if there is no pressure
difference. (the compressor may be
locked.)
Replace the INV board.
GB