Refrigerant Shortage - Daikin VRV II-Q RQYQ8-48PY1B Service Manual

SiBE341027

2.29 Refrigerant Shortage

U0
Remote
Controller
Display
Applicable RQYQ-PY1B
Models
Method of Error Detect refrigerant shortage based on the temperature difference between low pressure or
suction pipe and heat exchanger.
Detection
Error Decision [In cooling mode]
Low pressure becomes 0.1MPa or less.
Conditions
[In heating mode]
The degree of superheat of suction gas becomes 20 degrees or more.
SH= Ts1 –Te
Ts1: Temperature detected by suction pipe thermistor
Te : Low pressure equivalent saturation temperature
★
Supposed
Causes
Service Diagnosis
Error is not determined. The unit continues operation.
Refrigerant shortage or refrigerant clogging (wrong piping)
Defective thermistor (R8T, R9T)
Defective low pressure sensor
Defective outdoor unit PCB (A1P)
Troubleshooting by Remote Controller
149