Mitsubishi Electric e Series Service Handbook page 136

[ IX Troubleshooting ]
(2) Inverter output related troubles
[1] (1)
Check the
INV board er-
ror detection
circuit.
(2)
[2] Disconnect the compressor
Check for wiring, and check the compres-
compressor sor Meg, and coil resistance.
ground fault
or coil error.
[3] Put the outdoor unit into opera-
Check wheth- tion.
er the inverter Check the inverter output volt-
is damaged. age after the inverter output
(During com- frequency has stabilized.
pressor oper-
ation)
HWE20010
Items to be checked
Disconnect the inverter
output wire from the ter-
minals of the INV board
(SC-U, SC-V, SC-W).
Put the outdoor unit into
operation.
Phenomena
1) Overcurrent error
(4250 Detail code No. 101, 102,
103, 106, and 107)
2) Logic error
(4220 Detail code No. 111)
3) ACCT sensor circuit failure
(5301 Detail code No.117)
4) IPM open
(5301 Detail code No.119)
1) Compressor Meg failure
Error if less than 1 Mohm.
2) Compressor coil resistance failure
Coil resistance value of 0.092 ohm
(20°C)
1) Overcurrent-related problems oc-
cur immediately after compressor
startup.
Error code : 4250
Detail code : 101, 106, 107
2) There is a voltage imbalance be-
tween the wires after the inverter
output voltage is stabilized.
Greater than the larger of the fol-
lowing values: imbalance of 5% or
5V
- 127 -
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
compressor.
Replace the compressor.
a. Check items [1] through [2]
for problems.
b. Check that high and low
pressures are balanced.
c. Check that no liquid refrig-
erant is present in the
compressor.
→Go to "d." when the
problem persists after
compressor startup was
repeated several times.
If normal operation is re-
stored, check the crank-
case heater for problems.
d. Check that there is a pres-
sure difference between
high and low pressures af-
ter compressor startup.
→Check the high pressure
with LED monitor for
changes.
Replace the compressor if
there is no pressure differ-
ence. (the compressor
may be locked.)
Replace the INV board if there
is a voltage imbalance.
Check the crankcase heater
for problems if there is no volt-
age imbalance.
→When the error occurred, liq-
uid refrigerant may have been
present in the compressor.
GB