Daikin AT12BV1LS Pocket Manual page 137

Troubleshooting
5.3.5 Over-voltage Detection
Remote
Controller
Display
Method of
Malfunction
Detection
Malfunction
Decision
Conditions
Supposed
Causes
Trouble
shooting
Note: If the model doesn't have SPM, replace the outdoor unit
136
U2
An abnormal voltage rise is detected by checking the
specified over-voltage detection circuit.
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 5
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
Be sure to turn off power switch before connect or
Caution disconnect connector, or parts damage may be occurred.
Check the supply voltage.
Supply voltage as
specified?
YES
Turn on the
power again.Error displayed
again?
YES
Repeat a
couple of times.
A
Disturbance factors
∗ Noise ∗ Power supply distortion
PCB.
NO
Correct the power
supply.
NO
A
Replace the SPM.
(Replace the outdoor
unit PCB.)
Check for such factors
for a long term.
Service Diagnosis
Si10-417
(R2957)