Mitsubishi Electric PURY-P120TJMU-A, Service Handbook

Page: 332 / 411

[
IX
Troubleshooting ]
- 323 - HWE0913A GB
Items to be checked Phenomena Remedy
[4]
Check whether
the inverter is
damaged.
(During com-
pressor opera-
tion) Put the outdoor unit into oper-
ation.
Check the inverter output volt-
age after the inverter output
frequency has stabilized. 1) Overcurrent-related problems oc-
cur immediately after compressor
startup.Error code : 4250Detail
code : 101, 106, 107 a.Check items [1] through [3]
for problems.
b.Check that high and low
pressures are balanced.
c.Check that no liquid refriger-
ant is present in the com-
pressor.
Go to "d." when the prob-
lem persists after compres-
sor startup was repeated
several times.
If normal operation is re-
stored, check the belt heater
for problems.
d.Check that there is a pres-
sure difference between
high and low pressures after
compressor startup.
Check the high pressure
with LED monitor for chang-
es.
Replace the compressor if
there is no pressure differ-
ence. (the compressor may
be locked.)
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 Replace the INV board if there
is a voltage imbalance.
Check the belt heater for prob-
lems if there is no voltage im-
balance.
When the error occurred,
liquid refrigerant may have
been present in the compres-
sor.
[5]
Check the fan
motor ground
fault or the
winding. Remove the wire for the out-
door fan motor, and check the
fan motor megger and the
winding resistance. 1) Fan motor megger failure
Failure when the megger is 1Mohm
or less. Replace the fan motor.
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)
[6]
Check the FAN
board failure. (1) Check the fan output wir-
ing. Connector contact failure
Œ
Board side (CNINV)
Œ
Fan motor side
Connect the connector.
(2) Check the connector CN-
VDC connection. Cnnector contact failure Connect the connector.
(3) Check the FAN board
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.) Replace the FAN board.
2) The same error occurs even after
the operation is restarted.
[YJMU-A]