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© 2015 Emerson Climate Technologies, Inc.
AE4-1387 R7
INTRODUCTION
The ZS**KAE Copeland Scroll
™
compressor represents
the latest generation of compliant scroll technology for
the refrigeration industry.
Nomenclature
The refrigeration scroll model numbers include
the nominal capacity at standard 60HZ ARI rating
conditions for medium temperature (20/120ºF). For
additional information on this product, please refer
to the Online Product Information accessible from
the Emerson Climate Technologies web site at www.
emersonclimate.com.
Z = Scroll
S = Extended Medium Temperature Application
09K = nominal Capacity (x 1,000 Btu/hr)
A = Compressor Generation
E = POE Oil
Operating Envelope
The ZS**KAE refrigeration scroll compressor models can
be used with a variety of refrigerants depending on the
model selected and the lubricant used. (See
Table 1
.)
The ZS**KAE models are intended for extended
medium and high temperature refrigeration type duty.
The approved operating envelopes for these models
are such that they are ideally suited for applications
such as ice machines, bulk milk and frozen carbonated
beverage/frozen uncarbonated beverage. The models
and operating envelopes are depicted in
Figures 1A,
1B
and
1C
.
APPLICATION CONSIDERATIONS
Accumulators
Due to the scrolls’ inherent ability to handle liquid
refrigerant in flooded start and defrost cycle
operation conditions, accumulators may not be
required. An accumulator is required on single
compressor systems when the charge limitations
exceed those values listed in
Table 2
. On systems
with defrost schemes or transient operations that
allow prolonged uncontrolled liquid return to the
compressor, an accumulator is required unless a
suction header of sufficient volume to prevent liquid
migration to the compressor is used.
Excessive liquid flood back or repeated flooded starts
will dilute the oil in the compressor causing inadequate
lubrication and bearing wear. Proper system design will
minimize liquid flood back, thereby ensuring maximum
compressor life.
Superheat Requirements
In order to assure that liquid refrigerant does not return
to the compressor during the running cycle, attention
must be given to maintaining proper superheat at the
compressor suction inlet. Emerson recommends a
minimum of 20°F (11°C) superheat, measured on the
suction line 6 inches (152mm) from the suction valve,
to prevent liquid refrigerant floodback.
Another method to determine if liquid refrigerant is
returning to the compressor is to accurately measure
the temperature difference between the compressor
oil crankcase and the suction line. During continuous
operation we recommend that this difference be a
minimum of 50°F (27°C). This “crankcase differential
temperature” requirement supersedes the minimum
suction superheat requirement in the last paragraph.
To measure oil temperature through the compressor
shell, place a thermocouple on the bottom center (not
the side) of the compressor shell and insulate from the
ambient.
During rapid system changes, such as defrost or ice
harvest cycles, this temperature difference may drop
rapidly for a short period of time. When the crankcase
temperature difference falls below the recommended
50°F (27°C), our recommendation is the duration should
not exceed a maximum (continuous) time period of two
minutes and should not go lower than a 25°F (14°C)
difference.
Contact your Emerson Climate Technologies
representative regarding any exceptions to the above
requirements.
Crankcase Heaters
Crankcase heaters are required on all ZS**KAE scroll
compressors where the system charge exceeds charge
limit.
The listed crankcase heaters are intended for use
only when there is limited access (See
Table 3
). The
heaters are not equipped for use with electrical conduit.
Where applicable, electrical safety codes require lead
protection, a crankcase heater terminal box should be
used. Recommended crankcase heater terminal box
and cover kit numbers are listed in
Table 3A
. If there
