Mitsubishi Electric PUHY-P250YJM-A, Service Manual

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[
X
Troubleshooting ]
- 205 -
HWE10190 GB
Items to be checked Phenomena Remedy
[3]
Check whether
the inverter is
damaged.
(No load)
(1) Disconnect the inverter
output wire from the ter-
minals of the INV board
(SC-U, SC-V, SC-W).
1) Inverter-related problems are de-
tected.
Connect the short-circuit con-
nector to CN6, and go to sec-
tion [1].
(2) Disconnect the short-cir-
cuit connector from CN6
on the INV board.
2) Inverter voltage is not output at the
terminals (SC-U, SC-V, and SC-W)
Replace the INV board.
(3) Put the outdoor unit into
operation.
Check the inverter output
voltage after the inverter
output frequency has sta-
bilized.
3) There is an voltage imbalance be-
tween the wires.
Greater than 5% imbalance or 5V
Replace the INV board.
4) There is no voltage imbalance be-
tween the wires.
Normal
*Reconnect the short-circuit
connector to CN6 after check-
ing the voltage.
[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 error occurs immediate-
ly after the compressor startup.
(4250 Detail code No.101,106,107)
a) Go over the check items [1]
through [3] to find the problem.
b) Check if the high/low pressure
are in proper balance.
c) Check that no liquid refrigerant is
present in the compressor.
→ Proceed to d) if no improve-
ment is seen after several times
of reboot.
Even if it was recovered after the
reboot, check the crankcase
heater just to make sure there is
no problem with it.
d) After the reboot, check if there is
sufficient pressure difference
between high and low pressure.
→ Check on LED monitor if the
high pressure changes.
If it does not, replace the com-
pressor.
(The compressor may be
locked.)
2) After the inverter output voltage be-
came stable, an imbalance (stated
below) is seen between each wires.
Greater than the larger of the follow-
ing values: imbalance of 5% or 5V
In the case of imbalance, re-
place the INV board.
Even if there is no imbalance
seen, check the crankcase
heater just to make sure there
is no problem with it.
→ Some liquid refrigerant
might have been present in the
compressor when the problem
occurred.
[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
ΠBoard side (CNINV)
ΠFan 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.
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