Mitsubishi Electric CAHV-P500YA-HPB Service Handbook page 139

[ IX Troubleshooting ]
[4] Put the outdoor unit into oper-
Check whether ation.
the inverter is Check the inverter output volt-
damaged. age after the inverter output
(During com- frequency has stabilized.
pressor opera-
tion)
[5] Remove the wire for the out-
Check the fan door fan motor, and check the
motor ground fan motor megger and the
fault or the winding resistance.
winding.
[6] (1)
Check the fan
inverter board
failure.
(2)
(3)
HWE10060
Items to be checked
Check the fan output wir-
ing.
Check the connector CN-
VDC connection.
Check the FAN board
failure.
Phenomena
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
1) Fan motor megger failure
Failure when the megger is 1Mohm
or less.
2) Fan motor disconnection
Standard: The winding resistance
is approximately several ohm.
(It varies depending on the temper-
ature, or while the inner thermo is
operating, it will be
Connector contact failure
Board side (CNINV)
Fan motor side
Cnnector contact failure
1) The voltage imbalance among
each motor wiring during operation
(The voltage imbalance is greater
than the larger of the values repre-
sented by 5% or 5V.)
2) The same error occurs even after
the operation is restarted.
- 132 -
Remedy
a. Check items [1] through [3]
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.
Replace the fan motor.
ohm)
Connect the connector.
Connect the connector.
Replace the FAN board.
GB