21
ENGLISH
- Do a leak test of all joints of the tubing(both
indoor and outdoor) and both gas and liquid
side service valves.
Bubbles indicate a leak. Be sure to wipe off
the soap with a clean cloth.
- 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 re-
duced to normal, disconnect the hose from
the cylinder.
*The feature can be changed according to a
type of model.
- Remove the caps from the 2-way and 3-way
valves.
- Remove the service-port cap from the 3-way
valve.
- Apply a soap water or a liquid neutral deter-
gent on the indoor unit connection or outdoor
unit connections by a soft brush to check for
leakage of the connecting points of the pip-
ing.
- If bubbles come out, the pipes have leakage
Lo
Hi
Outdoor unit
Manifold valve
Charge hose
Nitrogen gas
cylinder(in vertical
standing position)
Pressure
gauge
Indoor unit
Soap water method
- 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.
Note that both the liquid and the gas side
service valves on the outdoor unit are kept
closed at this stage.
- Leak test
Connect the manifold valve(with pressure
gauges) and dry nitrogen gas cylinder to this
service port with charge hoses.
Leak testing with vacuum pump
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.
!
WARNING
There is a risk of fire and explo-
sion.
- Inert gas (nitrogen) should be
used when you check plumbing
leaks, cleaning or repairs of pipes etc.
If you are using combustible gases includ-
ing oxygen, product may have the risk of
fires and explosions.
!
CAUTION
Be sure to use a manifold valve for air
purging. If it is not available, use a stop
valve for this purpose. The knob of the
3-way valve must always be kept close.
- Pressurize the system to maximum
250 P.S.I.G. (17.6kgf/cm
2
G) (R-22
model) or 400 P.S.I.G. (28.1kgf/cm
2
G)
(R-410A model) with dry nitrogen gas
and close the cylinder valve when the
gauge reading reaches 250 P.S.I.G.
(17.6kgf/cm
2
G) (R-22 model) or 400
P.S.I.G. (28.1kgf/cm
2
G) (R-410A model).
Next step is leak test with liquid soap.
!
