U0" Outdoor Unit: Refrigerant Shortage Alert - Daikin RTSQ20PY1 Service Manual

Troubleshooting by Indication on the Remote Controller
U0
4.44 " " Outdoor Unit: Refrigerant Shortage Alert
U0
Remote
Controller
Display
Applicable RTSQ8P~16P (Outdoor Unit)
Models
Method of Detect refrigerant shortage based on the temperature difference between low pressure or
suction pipe and heat exchanger.
Malfunction
Detection
Malfunction [In cooling mode]
Low pressure becomes 0.1MPa or below.
Decision
[In heating mode]
Conditions
The degree of superheat of suction gas becomes 20 degrees and over.
SH= Ts1 –Te
Ts1: Suction pipe temperature detected by thermistor
Te : Saturated temperature corresponding to low pressure
★
Supposed
Causes
293
Malfunction is not determined. The unit continues operation.
Refrigerant shortage or refrigerant clogging (piping error)
Defective thermistor (R4T, R8T)
Defective low pressure sensor
Defective outdoor unit PCB (A1P)
SiBE31-801_C
Troubleshooting