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© 2016 Emerson Climate Technologies, Inc.
AE4-1303 R15
levels, the system is either low on charge or there
isaowblockageinthesystem.
5. If suction pressure does not drop and discharge
pressure does not rise to normal levels, reverse
any two of the compressor power leads and
reapply power to make sure compressor was not
wired to run in reverse direction. If pressures still
do not move to normal values, either the reversing
valve (if so equipped) or the compressor is faulty.
Reconnect the compressor leads as originally
conguredandusenormaldiagnosticprocedures
to check operation of the reversing valve.
6. To test if the compressor is pumping properly,
the compressor current draw must be compared
to published compressor performance curves
using the operating pressures and voltage of
the system. If the measured average current
deviates more than ±15% from published values,
a faulty compressor may be indicated. A current
imbalance exceeding 15% of the average on the
three phases should be investigated further. A
more comprehensive trouble-shooting sequence
for compressors and systems can be found in
Section H of the Emerson Electrical Handbook,
Form No. 6400.
7. Before replacing or returning a compressor: Be
certain that the compressor is actually inoperable.
As a minimum, recheck a compressor returned
from the eld in the shop or depot for Hipot,
winding resistance, and ability to start before
returning. More than one-third of compressors
returned to Emerson Climate Technologies, Inc.
for warranty analysis are determined to have
nothing found wrong. They were misdiagnosed in
theeldasbeinginoperable.Replacingworking
compressors unnecessarily costs everyone.
Refrigerant Retrots
NOTICE
ZR compressors are UL recognized for use
with R-22, R-407C, or R-134a only. Use of any
other refrigerants will void the compressor UL
recognition.
Only those systems that are in need of service should
be considered for a refrigerant retrot if R-22 is not
available. Systems that are operating without issue
should be maintained and not be considered for a
refrigerantretrot.Inmostifnotallcases,theretrotted
system will not be as energy efcient as the R-22
system.
Only those refrigerants approved by Emerson Climate
Technologies, Inc. and the OEM should be considered.
For a list of Emerson approved refrigerants please
refer to Form 93-11, Refrigerants and Lubricants
Approved for Use in Copeland Compressors. Please
consult with the OEM to obtain their input and approval
onrefrigerantretrotting.
If the compressor lubricant is mineral oil, it must be
changedtoPOEforasuccessfulretrot.Seethesection
Removing Oil for instructions on how to remove the oil
charge from the compressor.
POE oil should be added to the compressor through the
oil charging connection on the sump of the compressor.
Thecompressorshouldbelledto1/2sight-glass.
For detailed R-407C retrot instructions please refer
to Form 95-14, Refrigerant Changeover Guidelines
for R-22 to R-407C.Forotherretrotguidelinesplease
refer to the equipment OEM.
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