Over-Voltage Detection - Daikin ATXS35EV1B7 Service Manual

Troubleshooting

4.25 Over-voltage Detection

U2
Remote
Controller
Display
Method of An abnormal voltage rise is detected by checking the specified over-voltage detection circuit.
Malfunction
Detection
Malfunction 25/35 class
Decision
Conditions
50 class
Supposed
Causes
Troubleshooting
126
An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer
(The voltage is over 400V).
The system will be shut down if the error occurs 255 times.
Clearing condition: Continuous run for about 10 minutes (normal)
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)
Supply voltage not as specified
Over-voltage detection circuit defective
PAM control part(s) defective
Short circuit inside the fan motor winding.
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Check the supply voltage.
Supply voltage as
specified?
YES
Rotate fan by hand.
Does fan rotate
smoothly?
YES
Turn on the
power again. System
restarted?
NO
Repeat a
couple of times.
NO
NO
(Precaution before turning on the power again)
Make sure the power has been off for
at least 30 seconds.
YES
Disturbance factors
∗ Noise ∗ Power supply distortion
SiBE04-824
Correct the power supply.
Replace fan motor and
outdoor unit PCB.
Check for such factors for a
long term.
∗ Try to get restarted a
couple of times.
Replace the PM1.
(Replace the outdoor unit
PCB.)
(R8347)
Service Diagnosis