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YMGI, Engineered Comfort Products for A Sustainable and Efficient Green World !
INSTALLATION OF REFRIGERANT PIPES
CONNECTION OF REFRIGERANT PIPE
NO.
Name
Coping plate
Rear side plate
Front side plate
Gas side stop valve
NO.
Name
Liquid side stop valve
Right connection board
Front connection board
NO.
A
B
C
D
Name
Front connection
Bottom connection
Side connection
Rear connection
①
②
③
④
⑤
⑥
⑦
1) Unscrew the coping plate, front side plate, right connection board and front connection board.
2) The refrigerant pipes can be installed in four directions, please choose the proper direction.
3) Knock the holes in the plate of the chosen direction with the drill and hammer.
4) Connect the pipes to the stop valves.
5) Bend the pipes to go through the knockout holes.
6) Cover the through-holes with sealing materials to prevent the water, dust or small animals going into the
outdoor unit.
LEAK TEST
1) Please make sure that the stop valves of the outdoor unit are closed during the operation.
2) The leak test should be made by pressurizing nitrogen gas.
3) Open the pressure reducing valve, pressurize the connection pipes to 1.0 MPa (145 PSI) slowly, wait ten
minutes, and make sure that the pressure will not drop.
4) Rise the pressure to 2.0-4.0 MPa (290-580 PSI) slowly, wait 24 hours, and make sure the pressure will not drop.
5) If the pressure does not decrease, the pipes have passed the test. Otherwise, look for where the gas leaks from.
P16 OF 32
YMGI, Engineered Comfort Products for A Sustainable and Efficient Green World !
INSTALLATION OF REFRIGERANT PIPES
VACUUM OPERATION
1) Make sure that the liquid and gas stop valve of the
outdoor unit are closed fully during the operation.
2) As shown in the following figure, expel the gas
from the refrigerant pipes by the vacuum pump.
3) Open the pump and turn on the knobs to evacuate the gas in the liquid and gas pipes.
4) When the pressure of the system is less than -0.1Mpa (-1bar), keep the system for more than one hour under
the condition.
5) Then turn off the knobs and the pump, and if the pressure of the pressure-vacuum gauge does not rise within
2 hours, the system is under a vacuum. Otherwise, the system has leaked, please look for where the gas
leaks in.
REFRIGERANT CHARGING
The refrigerant has been charged into the outdoor unit before shipped from the manufacturer, while additional
refrigerant still need be charged into the refrigerant pipe during the field installation.
Calculation of the Additional Refrigerant Charging
Note:
* The refrigerant charge of the outdoor unit does not include the charged additionally in the indoor unit, BU
module and the refrigerant pipe.
* For the length of the connecting pipe is decided on the field, the amount of additional refrigerant shall be
decided depending on the dimension and the length of the liquid pipe used on the field.
* Record the additional refrigerant charge for future maintenance.
* It does not need to add refrigerant if the total length of liquid pipe is within 30m.
Example: WMMS-90CH-V2B(59) (2)
Serial No.
Indoor unit 1
Model
Cassette type
WMMS-12EC-V2B(59)2
Indoor unit 2
Duct type
Indoor unit 3
Wall mounted type
Indoor unit 4
Wall mounted type
Indoor unit 5
Ceiling/Floor
Indoor unit 6
Wall mounted type
NO.
1
2
3
4
5
Name
Outdoor
unit
Pressure
reducing
valve
Nitrogen
Liquid
side stop
valve
Gas side
stop
valve
WMMS-12E
F
-V2B(59)2
WMMS-12E
U
-V2B(59)2
WMMS-18EW-V2B(59)2
WMMS-09EW-V2B(59)2
WMMS-09EW-V2B(59)2
INST
ALLER'S
INSTRUCTION
INST
ALLER'S
INSTRUCTION
Intake Air
Intake Air
Intake Air
Discharge Air
Discharge Air
