Mitsubishi Electric PUHY-P168, Service Handbook

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[
IX
Troubleshooting ]
Items to be checked Phenomena Remedy
[5]
Check the in-
verter circuit
trouble. Check whether the IPM screw
terminal is not loose. 1) Terminal screws are
loose.
Check for loose IPM terminal
screws and tighten them.
Check the exterior of the IPM. 2) IPM is cracked due to
swelling.
Replace the IPM. Check the oper-
ation in [3] or [4] after replacing the
IPM.
In the case of an output voltage im-
balance or error reoccurrence: Re-
place the G/A board.
In the case of an output voltage
imbalance or error reoccur-
rence after replacement:
Replace the INV board.
Check the resistances between
each terminal of IPM.
Refer to 9.[4].5.(5) for details on
IPM troubleshooting. 3) Check the resistances
between each terminal of
IPM.
Replace the IPM.Check the opera-
tion in [3] or [4] after replacing the
IPM.
In the case of an output voltage im-
balance or error reoccurrence: Re-
place the G/A board.In the case of
an output voltage imbalance or er-
ror reoccurrence after replace-
ment:
Replace the INV board.
4) All normal for items 1) - 3)
above.
Replace the IPM.
In the case of an output voltage im-
balance or error reoccurrence:
Replace the G/A board.In the case
of an output voltage imbalance or
error reoccurrence after replace-
ment:
Replace the INV board.
[6]
Check the fan
motor ground
fault or the
winding. Remove the wire for the outdoor
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 temperature, or
while the inner thermo is
operating, it will be
ohm
[7]
Check the FAN
INV board fail-
ure. (1) Check the fan output wiring. Connector contact failure
ΠBoard side (CNINV)
ΠFan motor side
Connect the connector.
(2) Check the connector CN-
VDC connection.
Connector contact failure Connect the connector.
(3) Check the FAN INV board
failure.
1) The voltage imbalance
among each motor wiring
during operation
The voltage imbalance is
greater than the larger of
the values represented
by 5% or 5 V.
Replace the FAN INV board.
2) The same error occurs
even after the operation
is restarted.
(4) Check the transformer on
the FAN INV board.
The same error occurs even if
the board is replaced as de-
scribed in (3) Replace the power-supply trans-
former on the FAN INV board.