Troubleshooting
SiENBE07-618_C
92
Service Diagnosis
4.24 Low-voltage Detection or Over-voltage Detection
Remote Control
Display
U2
Method of
Malfunction
Detection
Low-voltage detection:
An abnormal voltage drop is detected by the DC voltage detection circuit.
Over-voltage detection:
An abnormal voltage rise is detected by the over-voltage detection circuit.
Malfunction
Decision
Conditions
Low-voltage detection:
The voltage detected by the DC voltage detection circuit is below 150 V.
If the error repeats 16 times, the system is shut down.
Reset condition: Continuous run for about 60 minutes without any other error
Over-voltage detection:
An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer.
The compressor stops if the error occurs, and restarts automatically after 3-minute standby.
Supposed
Causes
Supply voltage is not as specified.
Defective DC voltage detection circuit
Defective over-voltage detection circuit
Defective PAM control part
Layer short inside the fan motor winding
Troubleshooting
Correct the power supply.
(R11138)
Caution
NO
YES
YES
NO
YES
NO
Replace the fan motor or
the outdoor unit PCB.
Check the supply voltage.
Rotate the fan by hand.
Disturbance factors
∗
Noise
∗
Power supply distortion
Repeat a few
times.
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
(Precaution before turning on the power again)
Make sure the power has been off for at
least 30 seconds.
Check for such factors for a
long term.
∗
Try to restart a few times.
Replace the PM1.
(Replace the outdoor unit
PCB.)
Turn on the
power again. System
restarted?
Does the fan
rotate smoothly?
Supply voltage as
specified?
SIENBE07-618_C_FRONT.pdf 104
9/02/2011 9:25:07
