8
5. Tightening Torque
Diameter, D Torque (Nm)
in mm
1/4 6.35 18
3/8 9.52 42
1/2 12.70 55
5/8 15.88 65
3/4 19.05 78
• Use proper torque wrench to tight the flare nuts.
• If the torque strength is weak, gas leakage may occur.
• If it is too tight, the flare nut may crack and it may be non
removable.
VACUUMING AND CHARGING
1. Purging The Piping And The Indoor Unit
Except for the outdoor unit which is pre-charged with
refrigerant, the indoor unit and the refrigerant connection pipes
must be airpurged because the air containing moisture that
remains in the refrigerant cycle may cause malfunction of the
compressor.
• Remove the caps from the valve and the service port.
• Connect the center of the charging gauge to the vacuum
pump. (Refer to Figure 7)
• Connect the charging gauge to the service port of the
3-way valve.
• Start the vacuum pump. Evacuate for approximately 30
minutes. The evacuation time varies with different vacuum
pump capacity. Confirm that the charging gauge needle has
moved towards -760mmHg.
Caution:
• If the gauge needle does not move to -760mmHg, be sure
to check for gas leaks (using the refrigerant detector) at
flare type connection of the indoor and outdoor unit and
repair the leak before proceeding to the next step.
• Close the valve of the charging gauge and stop the vacuum
pump.
• On the outdoor unit, open the suction valve (3 way) and
liquid valve (2 way) (in anti-clockwise direction) with 4mm
key for hexagon sacked screw.
2. Additional Charge
• The pre-charged of R22 in the Water Cooled Split Type
unit is suitable for standard pipe of length up to 7.6m.
• When the piping is more than the above stated standard
pipe length, kindly add additional charge referring to the
table below.
Model Gram/Meter
WSS10A 30
WSS15A 30
WSS20A 30
WSS25A 30
3. Charge Operation
This operation must be done by using a gas cylinder and a
precise weighing machine. The additional charge is topped-
up into the outdoor unit using the suction valve via the service
port.
• Remove the service port cap.
• Connect the low pressure side of the charging gauge to the
suction service port center of the cylinder tank and close
the high pressure side of the gauge. Purge the air from the
service hose.
• Start the air conditioner unit.
• Open the gas cylinder and low pressure charging valve.
• When the required refrigerant quantity is pumped into the
unit, close the low pressure side and the gas cylinder valve.
• Disconnect the service hose form service port. Put back the
service port cap.
UNIT OPERATION LIMITS
1. Environment
This unit is designed for indoor installation and operation only. This unit also limited to
water loop application only as the heat exchanger can only cater for this application.
2. Power Supply
A voltage variation of +/– 10% of rated voltage stated in the unit label is acceptable.
3. Allowable Operation Conditions
Ensure the operating temperature and conditions are in allowable range. Extreme variations
in temperature, humidity and corrosive water or air will adversely affect unit performance,
reliability and service life.
Water Entering Temp. (oC)
45
30
13
STD
Cooling
15 19 24
Indoor Temp. (oC WB)
4. Cooling only
