step 11:Air Purging and Leakage test
Air and moisture in the refrigeration system have
undesirable effects as indicated below:
• System pressure increase.
• Operating current rise.
• Cooling or heating efficiency drops.
• Moisture in the refrigeration circuit may freeze
and block the capillary tubing.
• Water may lead to corrosion of parts in the
refrigeration system.
Therefore, the indoor unit and tubing between
the indoor and outdoor units must be tested
for leakage and evacuated to remove any non-
condensables 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 has been completed.
Remove the service valve caps from both gas
and liquid sides on the outdoor unit.
• For detailed data of pipe length and
refrigerant amount, please refer to page 6.
caution
• both liquid and gas side service valves
on the outdoor unit are kept closed at this
stage.
• When relocate the unit to another place,
performevacuation using vacuum pump.
• Make sure the refrigerant added into the
air conditioner is in liquid form in any
case.
Caution in Handing
the stop Valve
• Operation of opening stop valve:
Open the valve stem until it hits against the
stopper. Do not try to open it further.
• Operation of closing stop valve:
Securely tighten the valve stem with a special
tool. Then securely tighten the valve stem cap
with a spanner or the like.
Refrigerant
Lo stop valve
Outdoor
(3-way valve)
Unit
Hi stop valve
(2-way valve)
tips and information
• A: Low pressure valve (3-way) - gas side.
• b: High pressure valve (2-way) - liquid side.
• C and D: they are the ends of indoor unit
connection
Valve body
Charge port
Valve stem
Stopper
Refer to the valve cap tightening torque value
as below:
Outer diam.
torque
(N.m)
(mm)
Ф6.35 (1/4")
15.7 (1.6kg.m) 19.6 (2.0kg.m)
Ф9.52 (3/8")
29.4 (3.0kg.m) 34.3 (3.5kg.m)
Ф12.70 (1/2")
49.0 (5.0kg.m) 53.9 (5.5kg.m)
Ф15.88 (5/8")
73.6 (7.5kg.m) 78.6 (8.0kg.m)
Indoor
Unit
Gas side
Liquid side
Half union
Flare nut
Cap
Additional
torque (N.m)
21