Troubleshooting
Si12-714
214
Service Diagnosis
5.24
Low-voltage Detection
Remote
Controller
Display
U2
Outdoor Unit LED
Display
A
5
1
4
2
1
3
1
4
4
Method of
Malfunction
Detection
An abnormal voltage rise or drop is detected by checking the detection circuit or DC voltage
detection circuit.
Malfunction
Decision
Conditions
An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer, or
the voltage being detected by the DC voltage detection circuit is judged to be below 150 V
for 0.1 second.
The system will be shut down if the error occurs 16 times.
Clearing condition: Continuous run for about 60 minutes (normal)
Supposed
Causes
Supply voltage not as specified
Over-voltage detector or DC voltage detection circuit defective
PAM control part(s) defective
Short circuit inside the fan motor winding.
Troubleshooting
Check the supply voltage.
Correct the power supply.
Replace the SPM or PM1.
(Replace the outdoor unit
PCB.)
Check for such factors for a
long term.
∗
Try to get restarted a
couple of times.
(R6567)
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Supply voltage as
specified?
NO
YES
YES
Turn on the
power again.
System restarted?
NO
Repeat a
couple of times.
YES
(Precaution before turning on the power again)
Make sure the power has been off for
at least 30 seconds.
Rotate fan by hand.
Replace fan motor and
outdoor unit PCB.
Does fan rotate
smoothly?
NO
Disturbance factors
∗
Noise
∗
Power supply distortion
