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© 2015 Emerson Climate Technologies, Inc.
AE4-1365 R4
acceptability of sound performance. When no testing
is performed, mufflers are recommended in heat
pumps. The mufflers should be located a minimum of
six inches (15 cm) to a maximum of 18 inches (46
cm) from the compressor for most effective operation.
The farther the muffler is placed from the compressor
within these ranges the more effective it may be. If
adequate attenuation is not achieved, use a muffler
with a larger cross-sectional area to inlet-area ratio.
Air Conditioning System Suction Line Noise and
Vibration
The vibration characteristics of the scroll compressor,
although low, include two very close frequencies. These
frequencies, which are present in all compressors,
may result in a low level “beat” frequency that may
be detected as noise coming along the suction line
into a house under some conditions. Elimination of
the “beat” can be achieved by attenuating either of
the contributing frequencies. The most important
frequencies to avoid are 50 and 60 Hz power supply
line and twice-line frequencies for single-phase
compressors and line frequency for three phase
compressors. This is easily done by using one of
the common combinations of design configuration
described in
Table 2.
The scroll compressor makes
both a rocking and torsional motion, and enough
flexibility must be provided in the line to prevent
vibration transmission into any lines attached to the
unit. In a split system the most important goal is to
ensure minimal vibration is all directions at the service
valve to avoid transmitting vibrations to the structure
to which the lines are fastened.
Under some conditions the normal rotational starting
motion of the compressor can transmit an “impact”
noise along the suction line. This may be particularly
pronounced in three-phase models due to their
inherently higher starting torque. This phenomenon,
like the one described previously, also results from the
lack of internal suspension, and can be easily avoided
by using standard suction line isolation techniques as
described in
Table 2
.
The sound phenomena described above are not
usually associated with heat pump systems because of
the isolation and attenuation provided by the reversing
valve and tubing bends.
Mounting Parts
Table 4
lists the mounting parts to be used with these
compressors. Many OEM customers buy the mounting
parts directly from the supplier, but Emerson’s
grommet design and durometer recommendation
should be followed for best vibration reduction through
the mounting feet. Please see
AE4-1111
for grommet
mounting suggestions and supplier addresses.
Electrical Connections
WARNING
A molded electrical plug must be used with all
-1XX and -8XX compressor bills of material. The
molded plug must be installed by hand or with an
approved installation tool. A hammer must not be
used to install the plug.
Three different electrical connections are used within
this compressor family as illustrated in the matrix on
Page 4.
NOTICE The molded plug for the ZP104-122KC
compressors is larger and will not fit on smaller
compressors in this family. Refer to Table 4 for the
correct part number. When a molded plug is used
with ZP92-122KC compressors the terminal cover
must be also be used. This is not the case for
smaller compressors with the round terminal fence.
CAUTION Never operate the compressor without
the terminal box cover installed.
Deep Vacuum Operation
CAUTION
Copeland Scroll compressors (as with any
refrigerant compressor) should never be used
to evacuate a refrigeration or air conditioning
system.
The scroll compressor can be used to pump
down refrigerant in a unit as long as the pressures
remain within the operating envelope shown in
Figure
1.
Prolonged operation at low suction pressures will
result in overheating of the scrolls and permanent
damage to the scroll tips, drive bearing and internal
seal. See
AE24-1105
for proper system evacuation
procedures.
Shell Temperature
CAUTION
Compressor top cap temperatures can be very
hot. Care must be taken to ensure that wiring or
other materials which could be damaged by these
