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© 2016 Emerson Climate Technologies, Inc.
AE4-1402 R4
Emerson EVC1
Operating Envelope
When using the Emerson EVC1 drive, the
compressor is designed to operate within the
requirements of the operating envelope as shown
in
Figure 3
.
Emerson EVC1 Starting and Stopping Routine
The drive controls the starting and stopping routine
of the variable speed scroll. This routine allows
soft starting and controlled stopping, an advantage
over traditional on-off control of fixed capacity units.
Please refer to the Emerson EVC1 drive user guide
for an exact explanation of the starting and stopping
process.
The variable speed scroll compressor incorporates
a fluid brake design to help mitigate reverse rotation
during shutdown. A momentary reverse rotation
sound may be heard. Refer to
Table 5
for more
information.
Other Features
Refer to the Emerson EVC1 drive user guide for
more features and functions of the drive.
Emerson EVC1
Drive and Variable Speed
Scroll Set-Up
A quick start guide is available with the Emerson EVC1
drive. Application Engineering is available to assist
during any part of this process.
Refrigerant
The ZPV063 compressors are approved for use with
R-410A only. Use of refrigerants other than R-410A
voids the UL recognition of these compressor models
since the motor overload system could be adversely
affected.
Operating Envelope
The compressor operating envelope at each speed
represents the allowable range of operating conditions
for the compressor at a constant 20°F (11°C) suction
superheat, except as noted in
Figure 3
.
Figure 3
is
a composite of the
allowable operating envelope at
various speeds for the ZPV063 compressor.
Operating the compressor at evaporating temperatures
that are higher than those specified in the envelopes
for the given speed will result in a higher oil circulation
rate. A higher oil circulation rate can reduce heat
exchanger efficiency and possibly result in oil
pump-out if the system has long interconnecting
piping. Customers that choose to operate in these
higher evaporating temperature areas should use a
compressor sample with a sight-tube during system
development testing to ensure that an adequate level
of oil is maintained in the compressor sump. Sight-
tubed compressors for monitoring the oil level are
available by contacting Application Engineering.
The lower right boundary of the operating envelope is
the minimum compression ratio required to keep the
scrolls loaded. Operation below this boundary could
result in the compressor intermittently loading and
unloading and noisy operation.
The upper left boundary of the envelope represents
the maximum compression ratio when operating
with 20F° (11°C) suction superheat. If the operating
condition approaches this boundary of the envelope
the compressor discharge temperature will begin to
approach the maximum scroll temperature allowed by
the discharge line thermistor.
If operating the compressor below 1800 RPM, an oil
boost cycle is required for operation between 1000
and 1800 RPM. Refer to the note in
Figure 3
for more
information on the oil boost cycle.
High Pressure Control
WARNING
A high pressure control must be used in all
applications.
A high pressure control must be used with these
compressors since they do not employ an internal
pressure relief valve (IPR). The maximum cut-out
setting must not exceed 650 psig (45 bar). The switch
should be wired in series with the unit contactor to
immediately stop compressor operation if there is a high
pressure event. The high pressure control should have
a manual reset feature for the highest level of system
protection. If an auto reset high pressure control is
used, the compressor should be locked out after three
consecutive trips. If a pressure transducer is used to
protect against high discharge pressure events the
transducer and control logic should comply with U.L.
and/or local safety requirements.
Low Pressure Control
A low pressure control is required to protect against loss
of charge and other system fault conditions that can
