Over-Voltage Detection / Low-Voltage Detection - Daikin F-Series Service Manual

SiEN12-710A

4.22 Over-voltage Detection / Low-voltage Detection

U2
Remote Control
Display
Method of
An abnormal voltage rise (or drop) is detected by checking the detection circuit or DC voltage
Malfunction detection circuit.
Detection
Malfunction " An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer, or
Decision
Conditions
" The system will be shut down if the error occurs 255 times.
" Clearing condition: Continuous run for about 60 minutes (normal)
Supposed " Supply voltage not as specified
Causes " Over-voltage detector or DC voltage detection circuit defective
" PAM control part(s) defective
" Short circuit inside the fan motor winding.
Troubleshooting
Service Diagnosis
the voltage being detected by the DC voltage detection circuit is judged to be below 150V for
0.1 second.
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
Troubleshooting
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 outdoor unit
PCB.
(R7150)
141