Daikin VRVII Manual page 282

Troubleshooting by Indication on the Remote Controller
Remote Controller Display
U2
Applicable Models
VRVII and -WII Series
Method of Error Detection
Detection of voltage of main circuit capacitor built in the
inverter and power supply voltage.
Error Decision Conditions
When the capacitor above only has a voltage of 360 V or
less (YL) and 210V or less (TL).
Supposed Causes
Power supply insufficient
Instantaneous failure
Open phase
Defective inverter PCB
Defective outdoor (outside) control PCB
Defective magnetic contact switch.
Defective main circuit wiring
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