~t;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
refrigemnt system.
The indoor unit and tubing between the indoor
and outdoor units must be leak-tested and the
system evacuated to remove any noncondensables
and moisture.
N0712 The outdoor unit contains /?22 chatge for the
total system.
❑ ~P*~*a=mwpwp.
Preparation:
Check that each tube (both liquid and gas side
tubes) between the indoor and outdoor units has
been properly connected and all wiring for the test
run has been completed. Remove the valve caps
fi-om both the gas and the liquid side semice valves
on the outdoor unit. Note that both liquid and gas
side service valves on the outdoor unit are kept
closed at this stage.
N07E: The outdoor unit contains /?22 charge for the
total system.
Leak Test:
1
Connect a manifold valve (with pressure gauges)
and dry nitrogen gas cylinder to the suction
semice port.
2 Pressurize the system to no more than 150
P.S.I.G. with&y nitrogen gas and close the
cylinder valve when the gauge reading reaches
150 P.S.I.G. Next, testfor leaks with liquid soap.
lYURION: Toavoid nitrogen entering the refrigerant system
in a /iquid state, the top of the cy/inder must be higher than its
bottom vvhen you pressurize the system. Usuall~ the cylinder
is used in a vertical standing position.
3 Do a leak test of alljoints of the tubing (both
indoor and outdoor) and both gas and liquid side
sewice valves. Bubbles indicate a leak. Be sure to
wipe off the soap with a clean cloth.
4 After the system isfound 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
Pres
Charge hose
r
Nitrogen gas cylinder
(in vertical standing
position).
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