U0 Refrigerant Shortage - Daikin R71FUV1 Service Manual

Si20-701_B
U0
3.85
Remote Controller Display
U0
Applicable Models
RZQ-K/H, RZQ(S)-B
Method of Error Detection
(In normal operation)
Refrigerant shortage is detected according to the
electronic expansion valve opening degree and
measured temperatures and pressures.
Error Decision Conditions
(In cooling operation)
When the electronic expansion valve opens fully and low
pressure is below 0.1 MPa (For RZQ-C, RZQG:
0.25MPa) continuously for 30 minutes.
(In heating operation)
When the electronic expansion valve opens fully and the
suction superheat is large (more than 20°C) continuously
for 30 minutes (For RZQ-C, RZQG: 60 minutes).
∗ Refrigerant shortage alarm is indicated but operation
continues.
Supposed Causes
The stop valve is not opened
Insufficient refrigerant amount
Clogged refrigerant piping system
352
Refrigerant Shortage
Troubleshooting by Remote Controller