Leakage Test And Evacuation; Preparation; Leakage Test - LG LUU188HV Installation Manual

LEAKAGE TEST AND EVACUATION

Air and moisture remaining in the refrigerant
system have undesirable effects as indicated
below.
1
Pressure in the system rises.
2
Operating current rises.
3
Cooling(or heating) efficiency drops.
4
Moisture in the refrigerant circuit may
freeze and block capillary tubing.
5
Water may lead to corrosion of parts in the
refrigeration system.
Therefore, the indoor/outdoor unit and
connecting tube must be checked for leak
tight, and vacuumed to remove incondensible
gas and moisture in the system.

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 on the outdoor unit. Check that
both the liquid and the gas side service valves
on the outdoor unit are kept closed at this
stage.

Leakage test

Connect the manifold valve(with pressure
gauges) and dry nitrogen gas cylinder to this
service port with charge hoses.
CAUTION
!
• Be sure to use a manifold valve for leakage
test.
If it is not available, use a stop valve for this
purpose. The "Hi" knob of the manifold
valve must always be kept close.
Pressurize the system to no more than 3.0
MPa (427 P.S.I.G) with dry nitrogen gas and
close the cylinder valve when the gauge
reading reached 3.0 MPa (427 P.S.I.G) Next,
test for leaks with liquid soap.
LEAKAGE TEST AND EVACUATION
CAUTION
!
• To avoid nitrogen entering the refrigerant
system in a liquid state, the top of the
cylinder must be higher than its bottom
when you pressurize the system. Usually,
the cylinder is used in a vertical standing
position.
1
Do a leakage test of all joints of the
tubing(both Indoor unit and outdoor unit)
and both gas and liquid side service
valves.
Bubbles indicate a leak. Be sure to wipe off
the soap with a clean cloth.
2
After the system is found to be free of
leaks, relieve the nitrogen pressure by
loosening the charge hose connector at the
nitrogen cylinder. When the system
pressure is reduced to normal, disconnect
the hose from the cylinder.
Outdoor unit
Manifold valve
Lo
15
Indoor unit
Pressure
gauge
Hi
Charge hose
Nitrogen gas
cylinder(in vertical
standing position)