MODEL PCA090480WH
CHAPTER 2
SERVICE
Section 3: Refrigeration Basics and Service
March 2013
2-3
Proprietary/Confidential
Page 43
© 2013 Twist, Inc.
(2)
Connect either copper tube or a manifold charging hose to the
1/4" flare fitting at the top of the pump and attach the other end
loosely to the valve on the compressor. Next, purge the air from
the hose and tighten the fitting at the system.
(3)
When it has been connected and purged, start pumping the oil
into the compressor with slow, even strokes. Always push
straight down on the pump.
(4)
After pumping the desired charge of oil into the compressor,
remove the connecting hose or tube from the system. Cap the
flare connection on the pump to help keep it clean and free of
contamination.
E.
Dealing with Non-Condensable Gases
A leak in the low-pressure side of an operating system may result in the
entrance of air. Before purging non-condensable gases from a system,
note the compressor operating discharge pressure and compare it with
the temperature of the refrigerant (see Appendix). Since air is non-
condensable under the temperatures and pressures encountered in an
air conditioning system, the system’s condensing pressure will increase
due to the pressures exerted by the trapped air. The amount of
increased pressure is dependent on the quantity of air trapped.
If non-condensable gases are suspected in the system, remove the
refrigerant charge and evacuate the system to get rid of the non-
condensable gases. Once this is completed, recharge the system with
the correct amount of refrigerant.
F.
Refrigerant
Leaks
Refrigeration systems must be absolutely air tight for two reasons:
First, any leakage will result in loss of the refrigerant charge. Second,
leaks allow air and moisture to enter the system, causing damage to
components.
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