Low-Voltage Detection Or Over-Voltage Detection - Daikin FTXN25KEV1B Service Manual

SiBE041102_A

4.23 Low-voltage Detection or Over-voltage Detection

U2
Remote
Controller
Display
Method of
Malfunction
Evaluation of zero-cross detection of power supply by the indoor unit PCB.
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
There is no zero-cross detection in approximately 10 seconds.
Conditions
Low-voltage detection:
Over-voltage detection:
Supposed
Causes
Service Diagnosis
Indoor Unit
Outdoor Unit
Indoor Unit
Outdoor Unit
The voltage detected by the DC voltage detection circuit is below 180 V.
The compressor stops if the error occurs, and restarts automatically after 3-minute standby.
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.
Power supply voltage is not as specified.
Defective DC voltage detection circuit
Defective over-voltage detection circuit
Defective PAM control part
Disconnection of compressor harness
Noise
Momentary fall of voltage
Momentary power failure
Defective indoor unit PCB
Troubleshooting
85