Application Engineering
B U L L E T I N
AE4-1374 R1
The tests outlined above are for common
applications of compressors in this family. Many
other applications of the compressor exist, and
tests to insure those designs can
’t possibly
be covered in this bulletin. Please consult with
Application Engineering on applications outside of
those outlined above for the appropriate application
tests.
ASSEMBLY LINE PROCEDURES
Installing the Compressor
WARNING
Use care and the appropriate material handling
equipment when lifting and moving compressors.
Personal safety equipment must be used.
Copeland Scroll compressors leave the factory
dehydrated and with a positive dry air charge. Plugs
should not be removed from the compressor until the
compressor has had sufficient time to warm up to the
factory ambient, if the compressor is stored outside in a
cold climate. The suggested warm up time is one hour
per 4°F (2K) difference between outdoor and indoor
temperature. It is suggested that the larger suction
plug be removed first to relieve the internal pressure.
Removing the smaller discharge plug could result in a
spray of oil out of this fitting since some oil accumulates
in the head of the compressor after Emerson
’s run
test. The inside of both fittings should be wiped with
a lint free cloth to remove residual oil prior to brazing.
A compressor containing POE oil should never be left
open longer than 5 minutes.
Assembly Line Brazing Procedure
WARNING
Personal safety equipment must be used during
brazing operation. Heat shields should be
used to prevent overheating or burning nearby
temperature
sensitive
parts.
Fire
extinguishing
equipment should be accessible in the event of a
fire.
Figure 8 discusses the proper procedures for brazing
the suction and discharge lines to a scroll compressor.
NOTICE It is important to flow nitrogen through the
system while brazing all joints during the system
assembly process. Nitrogen displaces the air and
prevents the formation of copper oxides in the system.
If allowed to form, the copper oxide flakes can later
be swept through the system and block screens such
as those protecting capillary tubes, thermal expansion
valves, and accumulator oil return holes. Any blockage
of oil or refrigerant may damage the compressor
resulting in failure.
© 2013 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
Pressure Testing
WARNING
Never pressurize the compressor to more than
350 psig (24 bar) for leak checking purposes.
Never pressurize the compressor from a nitrogen
cylinder or other pressure source without an
appropriately sized pressure regulating and relief
valve.
The pressure used on the line to meet the UL burst
pressure requirement must not be higher than 350
psig (24 Bar). Higher pressure may result in permanent
deformation of the compressor shell and possible
misalignment or bottom cover distortion.
Assembly Line System Charging Procedure
Systems should be charged with liquid on the high side
to the extent possible. The majority of the charge should
be pumped in the high side of the system to prevent low
voltage starting difficulties, hipot failures, and bearing
washout during the first-time start on the assembly line.
If additional charge is needed, it should be added as
liquid to the low side of the system with the compressor
operating. Pre-charging on the high side and adding
liquid on the low side of the system are both meant to
protect the compressor from operating with abnormally
low suction pressures during charging. NOTICE Do
not operate the compressor without enough system
charge to maintain at least 20 psig (1.4 bar) suction
pressure. Do not operate the compressor with the
low pressure cut-out disabled. Do no operate with
a restricted suction or liquid line. Depending on the
discharge pressure, allowing pressure to drop below
20 psig (1.4 bar) for more than a few seconds may
overheat the scrolls and cause early drive bearing
damage. NOTICE Do not use the compressor to
test the opening set point of a high pressure cutout.
Bearings are susceptible to damage before they have
had several hours of normal running for proper break in.
“Hipot” (AC High Potential) Testing
CAUTION
Use caution with high voltage and never hipot
when compressor is in a vacuum.
Copeland Scroll compressors are configured with the
motor down and the pumping components at the top
of the shell. As a result, the motor can be immersed
in refrigerant to a greater extent than hermetic
reciprocating compressors when liquid refrigerant is
present in the shell. In this respect, the scroll is more
like semi-hermetic compressors that have horizontal
motors partially submerged in oil and refrigerant. When
Copeland Scroll compressors are hipot tested with
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