Service manual

4
63
AIR PURGING
Air and moisture that remain in the refrigerant system, e.g. after installation, can cause undesirable effects
or damage as indicated below:
• Pressure in the system rises.
•
Operating current rises.
• Cooling or heating efficiency drops.
• Moisture in the refrigerant circuit may freeze and block capillary tubing.
• Water may lead to corrosion of parts in the refrigeration system.
• Damage of the compressor.
Therefore, the indoor unit and tubing between the indoor and outdoor unit must always be leak tested and
evacuated with aid of a vacuum pump to remove any noncondensables and moisture from the system.
Air purging with vacuum pump
• Preparation
Check that each tube(both liquid and gas side tubes) between the indoor and outdoor units have
been properly connected and all wiring for the test run has been completed. Remove the service valve
caps from both the gas and the liquid side valves on the outdoor unit.
Note that both the liquid and the gas side service valves on the outdoor unit must kept closed at this
stage.
• Pipe length and refrigerant amount:
• When relocate the unit to another place, perform evacuation using vacuum pump.
• Make sure the refrigerant added into the air conditioner is in liquid form in any case.
• Only use the type of refrigerant as stated on the rating label.
Caution in handling the packed valve
• Open the valve stem until it hits against the stopper. Do not try to open it further.
• Securely tighten the valve stem cap with a spanner or the like.
•
For valve stem cap tightening torque (See tightening torque table 1 in previous page).
A
C
D
B
Connective pipe lenght Air purging method
Additional amount above rating label amount of
refrigerant to be charged
Less than 5m Use vacuum pump. ------------------------
5~10m Use vacuum pump.
Liquid side pipe diameter:
ø 6.35 (mm)
(Pipe length-5)x30g
5~10m Use vacuum pump.
Liquid side pipe diameter:
ø 9.53 (mm)
(Pipe length-5)x30g
Fig. 22
Outdoor unit Indoor unit
Packed valve
on outdoor unit
see fig. 25
Half union
Flare nut
Stopper
Cap
V
alve body
Valve stem
Fig. 23