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9-8-2. Flow Selector Unit (FS Unit)
Leakage of SVD valve or SVS valve, etc; Positions to be checked and check code when a trouble such as miswiring occurred.
Phenomenon which appears as result
(Corresponding indoor unit or flow selector unit)
Part name
Trouble
mode
Operation mode
Correspon
din
g
indoor
unit
Not
cooled
Not
heated
May become
almost normal
capacity
l
Abnormal
cooling sound
¡
Circulating
sound
Detection of
check code
Judgment and position to be checked
Exam
p
le of
refrigerant
flow
Clogging
All heating operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Heating unit
Heating unit
¡
• TC1 is lower than normal indoor unit.
• Temperature of suction
g
as pipe at indoor side of the flow selector
unit is lower than that of normal FS unit.
Leakage
All cooling operation (SV11 ON)
Mainly cooling, part heating operation
Mainly cooling, part heating operation
All
Cooling unit
Cooling unit
¡
¡
SVD circuit –
SVS circuit
• Compared with normal indoor unit, TCJ is higher.
• Suction gas pipe at outdoor side of the flow selector unit is hot.
• Refrigerant circulating sound is heard in bypass from SVD valve
to SVS valve.
A
All cooling operation (SV11 OFF) All
¡¡
SVD circuit
• Refrigerant circulating sound is heard from SVD valve circuit.
• TCJ is high and SH is little. (Liquid pack)
All cooling operation (SV11 ON)
Mainly cooling, part heating operation
Mainly cooling, part heating operation
All
Cooling unit
Cooling unit
¡¡
SVD circuit
• Temperature of TCJ and TC1 become high similar to heating. (All
heating circuit)
• Dischar
g
e
g
as pipe at outdoor unit side of the flow selector unit is
rather hot.
•Refri
g
erant circulatin
g
sound is not heard from SVS valve, but it is
heard from SVD valve.
B
SVD valve
Miswiring/
Misinstallation
of coil
SVD ↔ SVS
All heating operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Heating unit
Heating unit
¡¡
SVS circuit
L18 “Flow
selector unit
error”
• Gas pipe at indoor side of the flow selector unit is cold. (Cooling
circuit, Liquid pack)
•Refri
g
erant circulatin
g
sound is not heard from SVD valve, but it is
heard from SVS valve.
C
Clogging
All cooling operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Cooling unit
Cooling unit
¡¡
SVSS circuit
• TCJ is higher than normal indoor unit.
• Gas pipe at indoor side of the flow selector unit is not cold.
• Refrigerant circulating sound is heard from SVSS valve.
All heating operation All
P19 “4-way
valve reversal
error”
SVS valve
Leakage
Mainly cooling, part heating operation
Mainly heating, part cooling operation
Heating unit
Heating unit
¡¡
SVS circuit
• Compared with normal indoor unit, TCJ is low.
• Temperature of suction gas pipe at outdoor side of the flow
selector unit is higher than that of normal flow selector unit.
• Refrigerant circulating sound is heard from SVS valve circuit.
Clogging
All heating operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Heating unit
Heating unit
¡
l
Indoor unit,
flow selector unit
• In start time, when exchan
g
in
g
mode from coolin
g
to heatin
g
after
defrost operation, refrigerant shock sound may be heard.
All cooling operation (SV11 ON)
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Cooling unit
Cooling unit
¡¡
SVDD circuit
• Refrigerant circulating sound may be heard from SVDD valve
circuit.
•Suction
g
as pipe at outdoor unit side of the flow selector unit ma
y
be hot.
Leakage
All heating operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Heating unit
Heating unit
¡¡
SVDD circuit
• Refrigerant circulating sound may be heard from SVDD valve
circuit.
Miswiring/
Misinstallation
of coil
SVD ↔ SVS
All cooling operation (SV11 ON)
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Cooling unit
Cooling unit
¡¡
SVDD circuit
• Refrigerant circulating sound may be heard from SVDD valve
circuit.
•Suction
g
as pipe at outdoor unit side of the flow selector unit ma
y
be hot.
SVDD
valve
All heating operation
Mainly cooling, part heating operation
Mainly heating, part cooling operation
All
Heating unit
Heating unit
¡
l
Indoor unit,
flow selector unit
• In start time, when exchan
g
in
g
mode from coolin
g
to heatin
g
after
defrost operation, refrigerant shock sound may be heard.