Refrigerant Shortage Alert - Daikin VRV-WIII RWEYQ72PTJU Service Manual

SiUS30-1301

3.37 Refrigerant Shortage Alert

U0
Error Code
Applicable RWEYQ72P, 84P
Models
Method of Error
Detect refrigerant shortage based on the temperature difference between low pressure equivalent
Detection saturation temperature or suction pipe and heat exchanger temperature.
Error Decision
[In cooling]
Low pressure becomes 14.5 psi or less.
Conditions
[In heating]
The degree of superheat of suction gas becomes 68°F and over.
SH = Ts1 –Te
Ts1: Suction pipe temperature detected by thermistor
Te : Saturated temperature corresponding to low pressure
Error is not determined. The unit continues the operation.
 Refrigerant shortage or refrigerant clogging (piping error)
Supposed
 Defective thermistor
Causes
 Defective low pressure sensor
 Defective condensing unit PCB (A1P)
Service Diagnosis
Troubleshooting by Indication on the Remote Controller
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