Low-Voltage Detection Or Over-Voltage Detection - Daikin CTXS09GVJU Service Manual

SiUS12-814

5.26 Low-voltage Detection or Over-voltage Detection

U2
Remote
Controller
Display
Outdoor Unit LED A 5
Display
Method of
An abnormal voltage rise or drop is detected by checking the detection circuit or DC voltage
Malfunction detection circuit.
Detection
Malfunction
Decision
Conditions
Supposed
Causes
Troubleshooting
Service Diagnosis
1 4 2 1 3 1 4 4
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 shut down if the error occurs 16 times (only for low-voltage detection).
Clearing condition: Continuous run for about 60 minutes (normal)
Supply voltage not as specified
Over-voltage detector or DC voltage detection circuit defective
PAM control part(s) defective
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)
155