Mitsubishi Electric PURY-P72 Service Handbook page 323

[ IX Troubleshooting ]
[TJMU-A]
Items to be checked
[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 output wir-
Check the FAN ing.
board failure.
(2) Check the connector CN-
VDC connection.
(3) Check the FAN board
failure.
HWE09130
Phenomena
1) Overcurrent-related problems oc-
cur immediately after compressor
startup.
(4250 Details : No.101, 103, 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 ohm)
Connector contact failure
ŒBoard side (CNINV)
ŒFan 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 5 V.)
2) The same error occurs even after
the operation is restarted.
- 314 -
Remedy
a. Check items [1] through
[3].
b. Check that high and low
pressures are balanced.
c. Check that no liquid re-
frigerant 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 belt
heater for problems.
d. Check that there is a
pressure difference be-
tween high and low
pressures after com-
pressor startup.
Check the high pres-
sure with LED monitor
for changes.
Replace the compressor
if there is no pressure
difference. (the com-
pressor may be locked.)
If there is a voltage imbalance
<P72 model>
Replace the INV board.
<P96, P120, P144 models>
Replace the IPM.
If the problem persists, replace
the INV board.
If the problem persists after re-
placing the above parts, go to
section [2].
Check the belt heater for prob-
lems if there is no voltage im-
balance.
When the error occurred, liq-
uid refrigerant may have been
present in the compressor.
Replace the fan motor.
Connect the connector.
Connect the connector.
Replace the FAN board.
GB