U0 Refrigerant Shortage Alert - Daikin VRVII Manual

U0
3.58
Remote Controller Display
U0
Applicable Models
VRVIII, III-S and III-Q Series
Method of Error Detection
Detect refrigerant shortage based on the temperature
difference between low pressure or suction pipe and heat
exchanger.
Error Decision Conditions
[In cooling mode]
Low pressure becomes 0.1MPa or below.
[In heating mode]
The degree of superheat of suction gas becomes 20°C
and over.
SH = Ts1 –Te
Ts1: Suction pipe temperature detected by
thermistor
Te : Low pressure equivalent saturation
temperature
∗ Error is not determined. The unit continues the
operation.
Supposed Causes
Refrigerant shortage or refrigerant clogging (piping
error)
Defective thermistor
Defective low pressure sensor
Defective outdoor unit PCB
250
Troubleshooting by Indication on the Remote Controller
Refrigerant Shortage Alert