SiUS28-902_B
Troubleshooting by Indication on the Remote Controller
Service Diagnosis
135
3.37 Refrigerant Shortage
Remote
Controller
Display
U0
Applicable
Models
RZR, RZQ
Method of Error
Detection
(In normal operation)
Gas shortage is detected according to the electronic expansion valve opening degree and
measured temperatures and pressures.
Error Decision
Conditions
(In cooling operation)
When the electronic expansion valve opens fully and low pressure is below 14.5 psi
continuously for 30 minutes.
(In heating operation)
When the electronic expansion valve opens fully and the suction superheat is large (more than
68°F) continuously for 30 minutes.
Supposed
Causes
The stop valve is not opened.
Insufficient refrigerant amount
Clogged refrigerant piping system
Troubleshooting
Note:
Gas shortage alarm is indicated but the operation continues.
Open the stop
v
al
v
e.
Is the stop
v
al
v
e open?
Check the refrigerant
piping system for
clogging.
Collect refrigerant. After
v
ac
uu
m drying is complete,
charge an appropriate
amo
u
nt of refrigerant.
Is the refrigerant
amo
u
nt appropriate?
N
O
N
O
YES
YES
Be s
u
re to t
u
rn off the po
w
er s
w
itch
b
efore connecting or disconnecting
the connector or parts may
b
e damaged.
Caution
