Additional Refrigerant Charge - Westinghouse WHM24DMA21S Service Manual

Piping work and refrigerant charge
Air tight test
Do use nitrogen when performing air-tight test.
Connect the gauge manifold using charging hoses with a nitrogen cylinder to the check joints of the
liquid line and the gas line stop valves. Perform the air-tight test. Don't open the gas line stop
valves. Apply nitrogen gas pressure of 550 psig (3.8MPa). Check for any gas leakage at the flare
nut connections, or brazed parts by gas leak detector or foaming agent. It is OK if gas pressure
does not decrease. After the air tight test, release nitrogen gas.

Additional refrigerant charge

Although refrigerant has been charged into this unit, additional refrigerant charge
is required according to the piping length.
The additional refrigerant precharge quantity should be determined and charged into the system
•
according to the following procedure.
Record the additional refrigerant quantity in order to facilitate maintenance and servicing activities.
•
Refrigerant charge before shipment (W0 (oz.))
W0 is the outdoor unit refrigerant charge before shipment；
Xg is additional refrigerant outdoor unit needed to charge according to piping length during
installation.
Refrigerant
Model
precharged before
shipment (oz.)
24K
36K
48K/60K
Procedure
Completion Applying
of Ref. Nitrogen
Piping Gas
Air tight procedure
0ft.～24.6ft.
(0m～7.5m)
0
70.5
0
98.7
0
142.9
Check of
Pressure Pass
Decrease
Repairing
of Leakage
Part
Total refrigerant pipe length
Longer than 24.6ft. (7.5m)
Xg = 0.38oz/ft ×( Total pipe length(ft.) -24.6)
Xg = 0.38oz/ft ×( Total pipe length(ft.) -24.6)
Xg = 0.60oz/ft ×( Total pipe length(ft.) -24.6)
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