3-128
SM-18006
TROUBLESHOOTING
3.4.7 Setting of Forced Open Valve Mode
This mode is utilized to simplify the refrigerant recovery work, refrigerant evacuation work and air tight test
during servicing by fully opening the expansion valves of water source unit (MV1, MV3, MV4, MVB) and the
expansion valve of indoor unit (MV), and opening the solenoid valves of water source unit (SVA, SVB).
e.g. Refrigerant Recovery Work during Servicing
The following Figure 3.4 indicates the water source unit cycle condition when the power supply of water
source unit is cut off with fully closed MV1.
Recovering refrigerant from the access port of gas stop valve and liquid stop valve under the condition
above is incapable because the path of the heat exchanger (
) is blocked.
The following valves are forcibly opened during the “Forced Open Valve Mode” is activated.
● Expansion Valve for Water Source Unit (MV1)
● Expansion Valve for Water Source Unit Inverter Radiation (MV3)
● Expansion Valve for Water Source Unit Plate Type Heat Exchanger (MV4)
● Expansion Valve for Water Source Unit Subcooling Heat Exchanger Bypass (MVB)
● Solenoid Valve for Water Source Unit High-Low Pressure Bypass (SVA)
● Solenoid Valve for Water Source Unit Plate Type Heat Exchanger Bypass (SVB)
● Expansion Valve for Indoor Unit (MV)
Figure 3.4 Water Source Unit Cycle Condition
Example: Heat Pump System
Check Valve
Oil
Separator
Plate Type
Heat Exchanger
Inverter
Compressor
Accumulator
Heat Exchanger
(Double Tube Type)
Stop Valve (Gas)
for Indoor Unit
Stop Valve (Liquid)
for Indoor Unit
Refrigerant
Cylinder
Refrigerant
Recovery
Apparatus
Manifold
Gauge
Stop Valve for Liquid
Stop Valve for
Gas (High/Low)
S
S
S
HP
S
INV
S
Water
Outlet
Water
Inlet
P
S
S
S
S
S
S
S
S
S
S
S
Radiation Plate 1
P
Tchg
Td
1
Tsc
Tg
Te
Ta
Not
Used
RVR1
OFF
MV
4
CLOSE
MV
3
CLOSE
MV
B
CLOSE
MV
1
CLOSE
RVR
2
OFF
SVG
CLOSE
SVC
CLOSE
SVA
CLOSE
SVB
CLOSE
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