U2" Power Supply Insufficient Or Instantaneous Failure - Daikin ALTHERMA HT Service Manual

Troubleshooting by Indication on the Remote Controller
3.55 "U2 " Power Supply Insufficient or Instantaneous Failure
U2
Remote Control
Display
Subcode 20: high/low voltage problem
Subcode 21: converter problem
All indoor units
Applicable
Models
Detection of voltage of main circuit capacitor built in the inverter and power supply voltage.
Method of
Malfunction
Detection
When the abnormal voltage of main circuit capacitor built in the inverter and abnormal power
Malfunction
supply voltage are detected.
Decision
Conditions
 Power supply insufficient
Supposed
 Instantaneous power failure
Causes
 Defect of indoor inverter PC board [A4P (1
 Converting problem
220V. Use correct precautions when servicing.
198
Warning: CAPACITOR SHOCK HAZARD. The capacitors (top surfaces) can hold up to
ø ø
) or A5P (3 )]
ESIE09-08B
Troubleshooting