Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 52

Error code
None
Remote controller:
7-segment display:
1. Applicable model
All models
2. Error detection method
3. Condition of error displayed
4. Presumable cause
• Compressor anomaly
• Noise
Note:
LED Green Red
Stays Off Stays Off
Indoor
Stays Off Stays Off
Outdoor
5. Troubleshooting
Diagnosis
Are the
insulation resistance
and and coil resistance of
compressor OK?
YES
Is insulation
of respective harnesses OK?
YES
Is any hamess bitten
between pannel and casing
or etc?
NO
Check the outdoor unit grounding
wire and earth leakage breaker
Check of the outdoor unit grounding wire and earth leakage breaker
� Run an independent grounding wire from the grounding screw
of outdoor unit to the grounding terminal on the distribution
panel. (Do not connect to another grounding wire.)
� In order to prevent malfunction of the earth leakage breaker
itself, confirm the conformity of high harmonic regulation.
* Insulation resistance of compressor
• Immediately after installation or when the unit has been left
for long period without power supply, the insulation
resistance may drop to a few MΩ because of refrigerant
migrated in the compressor.
When the earth leakage breaker is activated at lower insulation
resistance, check the following points.
� 6 hours after power ON, check if the insulation resistance
recovers to normal.
When power ON, crankcase heater heat up compressor and
evaporates the refrigerant migrated in the compressor.
� Check if the earth leakage breaker is conformed to higher
harmonic regulation or not.
Since the unit has inverter, it is necessary to use components
conformed to high harmonic regulation in order to prevent
malfunction of earth leakage breaker.
50
–
Content
Earth leakage breaker activated
NO
NO
YES
–
Countermeasure
Replace compressor. *
Secure insulation
resistance.
Secure insulation
resistance.