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© 2015 Emerson Climate Technologies, Inc.
AE4-1365 R4
temperatures do not come into contact with these
potentially hot areas.
Certain types of system failures, such as condenser or
evaporator fan blockage or loss of charge, may cause
thetopshellanddischargelinetobrieyorrepeatedly
reach temperatures above 350°F (177°C) as the
compressor cycles on its internal overload protection
device. Care must be taken to ensure that wiring or
other materials which could be damaged by these
temperatures do not come into contact with these
potentially hot areas.
Suction and Discharge Fittings
Copeland Scroll compressors have copper plated
steel suction and discharge ttings. These ttings
are far more rugged and less prone to leaks than
copper ttings used on other compressors. Due to
the different thermal properties of steel and copper,
brazing procedures may have to be changed from
those commonly used. See Figure 7 for assembly line
andeldbrazingrecommendations.
System Tubing Stress
System tubing should be designed to keep tubing
stresses below 9.5 ksi (62 MPa), the endurance limit
of copper tubing. Start, stop and running (resonance)
cases should be evaluated.
Three Phase Scroll Compressor Electrical Phasing
Copeland Scroll compressors, like several other types
of compressors, will only compress in one rotational
direction. Direction of rotation is not an issue with
single phase compressors since they will always start
and run in the proper direction (except as described in
the section “Brief Power Interruptions”). Three phase
compressors will rotate in either direction depending
upon phasing of the power. Since there is a 50%
chance of connecting power in such a way as to cause
rotation in the reverse direction, it is important to
include notices and instructions in appropriate
locations on the equipment to ensure that proper
rotation direction is achieved when the system
is installed and operated. Verication of proper
rotation direction is made by observing that suction
pressure drops and discharge pressure rises when the
compressor is energized. Reverse rotation will result in
no pressure differential as compared to normal values.
A compressor running in reverse will sometimes make
an abnormal sound.
There is no negative impact on durability caused by
operating three phase Copeland Scroll compressors in
the reversed direction for a short period of time (under
one hour). After several minutes of reverse operation,
the compressor’s internal overload protector will trip
shutting off the compressor. If allowed to repeatedly
restart and run in reverse without correcting the
situation, the compressor bearings will be permanently
damaged because of oil loss to the system. All three-
phase scroll compressors are wired identically
internally. As a result, once the correct phasing is
determined for a specic system or installation,
connecting properly phased power leads to the
identiedcompressorelectrical(Fusite
™
) terminals will
maintain the proper rotational direction. It should be
noted that all three phase scrolls will continue to run in
reverse until the internal overload protector opens or
the phasing is corrected.
Brief Power Interruptions
Brief power interruptions (less than ½ second) may
result in powered reverse rotation of single-phase
Copeland Scroll compressors. This occurs because
high-pressure discharge gas expands backward
through the scrolls during interruption, causing the
scroll to orbit in the reverse direction. When power
is reapplied while reverse rotation is occurring, the
compressor may continue to run in the reverse
direction for some time before the compressor’s
internal overload trips. This will not cause any damage
to the compressor, and when the internal overload
resets, the compressor will start and run normally.
To avoid disruption of operation, an electronic control
that can sense brief power interruptions may be
used to lock out the compressor for a short time.
This control could be incorporated in other system
controls (such as defrost control board or the system
thermostat), or can be a stand-alone control. No time
delay is necessary for three phase models since the
motor starting torque is high enough to overcome
reverse rotation.
Manifolding Tandem Compressors
Tandem compressor assemblies are available for
purchase from Emerson. In lieu of purchasing the
assembled tandem, the OEM can choose to purchase
the tandem ready compressor and perform the
assembly. All of the ZP*KC compressors are available
for manifolding with another ZP*KC compressor
of equal capacity. Some tandems are assembled
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