Service Manual

8. Troubleshooting
236
SMGB0079 rev.0 - 01/2013
Alarm code
51
Abnormal operation of the current sensor (RAS-(3-6)H(V)N(P/C)E)
• The RUN LED ickers and “ALARM” is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section.
The unit number and the alarm code are displayed on the display of the outdoor unit PCB.
- This alarm code is displayed when the current transformer is abnormal (0 A detection or 5 A alarm condition) and
the alarm has more than three occurrences in 30 minutes.
- Condition of Activation:
 When the frequency of the compressor is maintained at 15~18 Hz after the compressor is started, one of the
absolute values of the running current at each phase U+, U-, V+ and V- is less than 1.5 A (including 1.5A)
 Before the compressor is operated (at the end of position control), the current wave value is less than 5.0 A
Abnormal
Replace comp.
Restart operation.
No
Faulty inverter PCB
Replace it. *2)
Compressor stops
immediately. (nearly 18Hz)
Compressor is not
operated.
Indication “P7” appears. *1)
How is compressor
operation when
restarted?
Is the coil resistance
of comp. normal?
Yes
Replace the inverter PCB.*2)Check the inverter PCB.
N O T E
• *1)P7isshownat7-segmentontheoutdoorunitPCB.
• *2)PerformthehighvoltagedischargeworkbyreferringtotheitemProcedureofcheckingothermainparts, 
inpart“Checkingprocedurefortheelectronicexpansionvalve”beforecheckingandreplacingtheinverter
parts.