Daikin RXYQ-TA Series Service Manual page 264

Troubleshooting by Error Code
251
A
Refrigerant is
melting (No power
applied for a period of 6
hours or more)
NO
Is the
insulation
resistance of the
relevant compressor
100 kΩ or more?
YES
There is
wiring disconnection in
the compressor.
NO
CHECK 4
Is the power
transistor normal?
YES
CHECK 4 Refer to page 295.
YES
NO
YES
NO
SiUS341615E
Eliminate the melting state of
refrigerant.
Replace the inverter compressor.
Replace the inverter compressor.
Replace the inverter PCB.
RXYQ72-120TA: A3P
RXYQ144/168TA: A3P, A6P
Recheck for the compressor and the
refrigerant system.
Service Diagnosis