Introduction; Nomenclature; Operating Envelope; Use Of R-513A Refrigerant - Emerson Copeland Scroll ZB KC Series Bulletin

1. Introduction

The ZB*KC/ZB*KCE Copeland Scroll™ compressor
represents the latest generation of compliant scroll
technology for the refrigeration industry.

2. Nomenclature

The refrigeration scroll model numbers include the
nominal capacity at standard 60HZ ARI rating conditions
for medium temperature (20/120°F). For additional
information on this product, please refer to the Online
Product Information at Emerson.com/OPI

3. Operating Envelope

The ZB*KC/ZB*KCE refrigeration scroll compressor
models can be used with a variety of refrigerants
depending on the model selected and the lubricant
used. (See Table 1 at the end of this bulletin.)
The ZB*KC and ZB*KCE models are intended for
medium 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 FCB/FUB. The models and
operating envelopes are depicted in Figure 2, Figure 3,
Figure 4 and Figure 5 at the end of this bulletin.

4. Use of R-513A Refrigerant

WARNING
Note: Refrigerant migration of R-513A into the
compressor crankcase could cause low oil viscosity
which could lead to compressor damage.
•
When using R-513A it is critical to meet the
following requirements
•
Maintain adequate superheat settings with a
minimum superheat of 20°F at the compressor
•
No liquid refrigerant
compressor at any time, especially during
standstill or during or after defrost
•
Pump down recommended.
•
The use of
recommended.
•
Retrofit R-513A is only allowed for compressors
which are approved for these refrigerants

5. 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
© 2020 Emerson Climate Technologies, Inc.
migration into
a crankcase heater
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.
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)
the
difference.
Contact your
representative regarding any exceptions to the above
requirements.
is

6. Crankcase Heaters

•
Single-phase
No crankcase heaters are required on single-phase
scroll compressors.
•
Three-phase - outdoor only
Crankcase heaters are required on three phase
compressors where the system charge exceeds 10
lbs.
5
AE4-1317 R14
Emerson Climate Technologies