Low-Voltage Detection Or Over-Voltage Detection - Daikin K-Series Service Manual

SiBE061121.book Page 116 Monday, April 25, 2011 3:21 PM
Troubleshooting

4.26 Low-voltage Detection or Over-voltage Detection

U2
Remote
Controller
Display
Method of Low-voltage detection:
An abnormal voltage drop is detected by the DC voltage detection circuit.
Malfunction
Detection
Over-voltage detection:
An abnormal voltage rise is detected by the over-voltage detection circuit.
Malfunction Low-voltage detection:
Decision
Conditions
Over-voltage detection:
Supposed
Causes
116
The voltage detected by the DC voltage detection circuit is below 150 ~ 180 V (depending on
the model).
An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer.
(The voltage is over 400 V.)
If the error repeats, the system is shut down.
Reset condition: Continuous run for about 11 minutes (50 class: 5 minutes) without any
other error
Supply voltage is not as specified.
Defective DC voltage detection circuit
Defective over-voltage detection circuit
Defective PAM control part
Layer short inside the fan motor winding
SiBE061121
Service Diagnosis