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SiUS30-1301
Troubleshooting by Indication on the Remote Controller
Service Diagnosis
245
Check for Causes of Wet Operation.
Referring to the Fault Tree Analysis (FTA) shown below, identify defective points.
Note:
1: "Superheated degree control" in cooling is exercised with the indoor unit electronic expansion
valve.
2: "Superheated degree control" in heating is exercised with the condensing unit electronic
expansion valve (EV1).
3: Guideline of superheated degree to judge as wet operation
1
Suction gas superheated degree: Not more than 37.4°F;
2
Discharge gas superheated
degree: Not more than 59°F, except immediately after compressor starts up or is running under
drooping control.
(Use the values shown above as a guideline. Even if the superheated degree falls in the range,
the compressor may be normal depending on other conditions.)
CHECK 5
Refrigerant acc
u
m
u
lation
O
v
ercharge of refrigerant
Defecti
v
e crankcase heater
Fre
qu
ent O
N
/OFF of compressor
[Cooling]
Indoor
u
nit
electronic
expansion
v
al
v
e opens
too m
u
ch. (
*
1)
[Heating]
Condensing
u
nit electronic
expansion
v
al
v
e opens too
m
u
ch. (
*
2)
Defecti
v
e control
of s
u
perheated
degree
Defecti
v
e indoor
u
nit electronic
expansion
v
al
v
e
Defecti
v
e condensing
u
nit electronic
expansion
v
al
v
e
Defecti
v
e
control
Defecti
v
e
control
Defecti
v
e
v
al
v
e coil
Defecti
v
e control PCB
Defecti
v
e
v
al
v
e
b
ody
Defecti
v
e
v
al
v
e coil
Defecti
v
e
v
al
v
e
b
ody
Defecti
v
e po
w
er press
u
re sensor
Defecti
v
e s
u
ction pipe thermistor
Defecti
v
e control PCB
¬
Refer to information in the
section.
¬
Does the
v
al
v
e coil ha
v
e normal
resistance and ins
u
lation?
(Refer to information in the
section.)
¬
Is the connector correctly connected?
Are the thermistor resistance
characteristics normal?
¬
Is the connector correctly connected?
Are the thermistor resistance
characteristics normal?
¬
Does the
v
al
v
e coil ha
v
e normal
resistance and ins
u
lation?
(Refer to information in the
section.)
¬
Are the
v
oltage characteristics normal?
¬
Is the connector correctly connected?
Does the thermistor ha
v
e normal
resistance characteristics?
¬
Is the press
u
re reading of the ser
v
ice
checker corresponding to the act
u
al
meas
u
rement of the sensor?
¬
Can the fan motor
b
e rotated
b
y
hand?
Does the fan motor coil ha
v
e
normal resistance and
¬
Does the air filter get clogged?
¬
Are there any o
b
stacles in the air
passage?
W
et operation
Degraded
e
v
aporating
capacity
Increased
resistance
in air
passage
Dirty e
v
aporator
Red
u
ced
air
qu
antity
Red
u
ced
fan o
u
tp
u
t
Defecti
v
e fan motor
Dirty filter
O
b
stacles
¬
Does the heat exchanger get clogged?
CHECK 11
CHECK 11
CHECK 6
Defecti
v
e indoor
u
nit
li
qu
id pipe thermistor
Defecti
v
e indoor
u
nit
gas pipe thermistor
Defecti
v
e control PCB
(incl
u
ding defecti
v
e
capacity setting)