Refrigerant Shortage (Error) - Daikin RZQG71~140L7V1B Service Manual

ESIE12-06

4.30 Refrigerant Shortage (Error)

U0
Remote
Controller
Display
Applicable
RZQG
Models
Method of Error
(In cooling)
Detection Detection based on difference in temperature between temperature set by remote controller and
indoor suction air temperature, electronic expansion valve opening degree, compressor
frequency and low pressure.
(In heating)
Detection based on difference in temperature between temperature set by remote controller and
indoor suction air temperature, electronic expansion valve opening degree during the control of
suction air superheating, high pressure, indoor heat exchanger temperature and indoor suction
air temperature.
Error Decision
(In cooling)
Conditions When compressor frequency does not increase even though the load is heavy because the
electronic expansion valve is opened to the fullest extent
(In heating)
When suction gas superheat degree is large, compressor frequency is low and the electronic
expansion valve is opened to the fullest extent even though heating load is heavy
[If high pressure is lower than saturated pressure for indoor heat exchanger temperature (or
indoor suction air temperature), error is confirmed.]
Supposed  Refrigerant shortage
Causes  Clogged refrigerant piping system
 Mismatching of wiring and piping
 Stop valve is not opened
Service Diagnosis
Troubleshooting by Remote Controller
225