Air Purging; Leak Testing - Friedrich M24CJ Manuel D'installation

In cases where the outdoor unit is installed
above the Indoor unit perform the following.
1
Tape the piping and connecting cable from
down to up.
2
Secure the taped piping along the exterior
wall. Form a trap to prevent water entering
the room.
3
Fix the piping onto the wall using saddle or
equivalent

Air Purging

The air and moisture remaining in the refriger-
ant system have undesirable effects as indi-
cated 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.
Therefore, after evacuating the system, take a
leak test for the piping and tubing between the
indoor and outdoor unit.
Seal a small opening
around the pipings
with gum type sealant.
Trap
Trap
Leak testing 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 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.
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. (17.6 kgf/cm
model) or 400 P.S.I.G. (28.1 kgf/cm
(R-410A model) with dry nitrogen gas
and close the cylinder valve when the
gauge reading reaches 250 P.S.I.G.
(17.6 kgf/cm 2 G) (R-22 model) or 400
P.S.I.G. (28.1 kgf/cm
Next step is leak test with liquid soap.
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 explosion.
Inert gas (nitrogen) should be used
when you check plumbing leaks, cleaning
or repairs of pipes etc.
If you are using combustible gases
including oxygen, product may have the
risk of fires and explosions.
21
2 G) (R-22
2 G)
2
G) (R-410A model).