Panasonic R410A service manual Service procedures, Alarm “P26”, HIC PCB trouble

4. Service procedures

(2) [Alarm “P26”]	IGBT short-circuit protection on inverter control (IPDU) PCB
HIC PCB trouble)

Is power OK?	No
	Correct power line.

Yes
Are
circuit wiring,
connector	No
connections, and	Correct.
reactor
connections
OK?
Yes

Has filter PCB	No
RY001 or RY002
relay activated?

Yes

Disconnect U.V.W. output

terminal on HIC PCB and No start operation.

Does alarm

“P26”

occur?

Yes

Is

compressor OK? No (Check for layer

short circuit.)

Yes

Is

resistance between

each terminal on No

HIC PCB OK? (See following page.)

Yes

Replace outdoor unit control PCB.

Has filter PCB	Yes	Replace filter PCB.
AC fuse blown?

No

Replace HIC PCB.

4

Replace compressor.

Check HIC PCB. Replace if PCB has failed.

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