Hitachi RAS-(2-6)HVNP1(E), Service Manual

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8 Troubleshooting
264
SMGB0087 rev.0 - 12/2013
Alarm code
51
Abnormal operation of the current sensor (RAS-(8-12)HN(P/C)(E))
- 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:
Š
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)
Š
Before the compressor is operated (at the end of position control), the current wave value is less than 5.0 A.
Check the inverter
PCB
Restart operation.
Replace the
compressor
How is compressor
operation when
restarted?
Is the coil resistance
of compressor
normal?
Yes
No
Compressor is not operated.
Indication “P7” appears. *1)
Faulty inverter
PCB.
Replace it. *2)
Compressor stops immediately
(nearly 18Hz)
Replace transistor
module
Abnormal
Replace the
inverter PCB. *2)
Normal
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.