Refrigerant Shortage - Daikin RZQ Series FCQ20EVA Service Manual

Troubleshooting by Remote Controller

4.38 Refrigerant Shortage

U0
Error Code
Applicable
RZQ100-140KCVLT
Models RZQ100-140KCTLT
Method of Error (In cooling)
Detection based on difference in temperature between set temperature by remote controller and
Detection
suction air temperature for indoor unit, electronic expansion valve opening degree, compressor
frequency and low pressure.
(In heating)
Detection based on difference in temperature between set temperature by remote controller and
suction air temperature for indoor unit, 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
[If low pressure drops when the compressor is at 41Hz, error is confirmed.]
(In heating)
When suction gas superheated degree is large, compressor frequency is low and the electronic
expansion valve is opened to the fullest extent even though heat load is heavy
[If high pressure is lower than saturated pressure for indoor heat exchanger temperature (or
indoor suction air temperature), error is confirmed.]
 Refrigerant shortage
Supposed
 Clogged refrigerant piping system
Causes
 Defective wiring and piping
 The stop valve is not opened.
Troubleshooting
Caution Be sure to turn off the power switch before connecting or disconnecting connectors, or parts may be damaged.
Check 12
shortage.
Is the refrigerant amount
Check the transmission wiring and piping
between the indoor and outdoor units.
and piping connection
141
Check for refrigerant
NO
appropriate?
YES
Is wiring
NO
matched?
YES
SiME281501E
Collect refrigerant.
After vacuum drying is
complete, charge an
appropriate amount of
refrigerant.
Match wiring and piping
connection.
Check 10
Check the refrigerant piping
system for clogging.
Service Diagnosis