MODEL PCA090480WH
CHAPTER 2
SERVICE
Section 3: Refrigeration Basics and Service
2-3
March 2013
Page 40
Proprietary/Confidential
© 2013 Twist, Inc.
3.
Servicing System and Charging
A.
Gauge
Manifold
The most important tool of the refrigeration serviceman is the gauge
manifold. It can be used for checking system pressures, charging
refrigerant, evacuating the system, purging non-condensable and
adding oil.
The gauge manifold consists of compound and high pressure gauges
mounted on a manifold with hand valves to isolate the common
connection or open it to either side as desired.
The left-hand gauge is a compound or suction pressure gauge. The
right- hand gauge is the high or discharge pressure gauge. Flexible
hoses are used to make connections from the manifold to the system.
Connecting the gauge manifold to a system is the most common service
function. To avoid introducing contaminants into the system, always
purge the hose connections with refrigerant. The service person
making the connections should always follow a consistent procedure.
Crack (open slightly) the high-pressure manifold valve, allowing
refrigerant to bleed through the common hose. Allow refrigerant to
bleed for a few seconds then close the high-pressure valve on the
manifold. Repeat the same procedure with the low-pressure valve.
Close the valves on the manifold and crack the low-pressure service
valve, connecting the manifold to the system, making it ready for use.
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