Friedrich M18YJ Manuel D'installation page 22

22
- 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
reduced to normal, disconnect the hose from
the cylinder.
Indoor unit
Outdoor unit
*The feature can be changed according a type
of model.
Soap water method
- 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
Manifold valve
Pressure
gauge
Lo Hi
Charge hose
Nitrogen gas
cylinder(in vertical
standing position)
Evacuation
- Connect the charge hose end described in
the preceding steps to the vacuum pump to
evacuate the tubing and indoor unit.
Confirm the "Lo" knob of the pressure Gauge
is open. Then, run the vacuum pump.
The operation time for evacuation varies with
tubing length and capacity of the pump. The
following table shows the time required for
Evacuation.
Outdoor unit
3-way valve(Close) 3-way valve(Close) 3-way valve(Close)
2-way valve(Close) 2-way valve(Close) 2-way valve(Close)
Required time for Evacuation when 30 gal/h
vacuum pump is used
If tubing length is
less than 10m (33 ft)
10 min. or more
- When the desired vacuum is reached, close
the knob of the 3-way valve and stop the
vacuum pump.
Gas side
Liquid side
Cap
If tubing length is
longer than 10m
(33 ft)
15 min. or more