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TABLE OF CONTENTS
Safety Instructions
....................................................... 2
Safety Icon Explanation
........................................... 2 Instructions
Pertaining to Risk of Electrical Shock, Fire, or Injury to Persons
.......................................... 3 Safety Statements
.................................................... 3
INTRODUCTION
......................................................... 4 CO2 FOR
LOW TEMPERATURE APPLICATIONS SUB-CRITICAL DX SYSTEM
...................................... 4
Nomenclature
........................................................... 4
Approved Oils & Refrigerants ..................................
4 Mounting Parts
......................................................... 4 Safety
Relief Valves ................................................. 5
High-Pressure Safety Controls ................................ 5
Active Oil Management ............................................
5 Accumulators
........................................................... 6
Screens
....................................................................
6 Mufflers
....................................................................
6 Electrical Connection
............................................... 7 Crankcase Heaters
.................................................. 7
Motor Protection
....................................................... 7 Operating
Envelope .................................................. 7
Charging Procedure
................................................. 7 Deep Vacuum
Operation .......................................... 7 Shell
Temperature .................................................... 8
Pump Down Cycle and Parallel Rack Application .... 8 Low Pressure
Safety Control .................................... 8 Minimum Run
Time .................................................. 8
ASSEMBLY LINE PROCEDURES ............................... 8
Installing the Compressor .........................................
8 Assembly Line Brazing Procedure ........................... 8 New
Installations
...................................................... 8 ‘Hipot’
(AC High Potential) Testing ........................... 9
MAINTENANCE AND REPAIR .................................... 9
Service Procedures
.................................................. 9 Compressor
Replacement After a Motor Burn ....... 10 General Guidelines and
More Information ............. 10
FIGURES
Figure 1 CO2 Low Temp. Subcritical DX System ...... 12 Figure 2
Specially designed rubber rommets Kit # 527-0157-00
......................................................................
13 Figure 3 Oil Management Control OMC-CO2 ............ 13 Figure 4
Suction Side Pressure Relief Valve Requirements
.............................................................
14
Figure 5 Three Phase Power Circuit .......................... 15
Figure 6 - ZO Compressor Operating Envelope ........ 15 Figure 7
Compressor Electrical Connection ............... 15
Revision Tracking R4
Pg. 2 New Pressure Safety Icon added Pg. 4 Caution tag added to
superheat requirement. Pg. 4 Notes about oil recharging values
added. Pg. 5 Model numbers chart moved to pag. 10 and ZOD34K3E and
ZOD104KCE added. Pg. 5 Regulatory Compliance reference updated. Pg.
5 ZO104KCE data updated. Pg. 5 High-pressure relief valve settings
changed. Pg. 6 Modified low pressure cut. Pg. 7 Charging Procedures
changed Pg. 9 Maintenance and Repair section added
Pg. 10 Table of AE-Bulletins and documentation related with this
Bulletin. Pg. 10 Nomenclature details added. Pg. 10 Oil and
Refrigerant table added Pg. 10 Crankcase kit table added Pg. 11 OMC
CO2 Specification Chart added Pg. 11 Drawing of Subcritical DX
System changed. Pg. 11 and Pg. 12 Mounting parts drawings added.
Pg. 11 Oil Management drawing added Pg. 13 Pressure Relief Valve
drawing changed. Pg. 14 Operating Envelop changed.
Revision Tracking R5 Pg.6 Added CO2 OMB Oil Management Links
Copeland Scroll™ Compressors for CO2 Subcritical Refrigeration
(R-744)
August 2019 AE4-1372 R5
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Safety Instructions
Copeland Scroll™ compressors are manufactured according to the
latest U.S. and European Safety Standards. Particular emphasis has
been placed on the user's safety. Safety icons are explained below
and safety instructions applicable to the products in this bulletin
are grouped on Page 3. These instructions should be retained
throughout the lifetime of the compressor. You are strongly advised
to follow these safety instructions.
Safety Icon Explanation
DANGER indicates a hazardous situation which, if not avoided,
will result in death or serious injury. WARNING indicates a
hazardous situation which, if not avoided, could result in death or
serious injury. CAUTION, used with the safety alert symbol,
indicates a hazardous situation which, if not avoided, could result
in minor or moderate injury. NOTICE is used to address practices
not related to personal injury. CAUTION, without the safety alert
symbol, is used to address practices not related to personal
injury. FLAMMABLE
PRESSURE indicates a dangerous proximity to high pressure
section of the system.
DANGER
WARNING
CAUTION
NOTICE
CAUTION
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Instructions Pertaining to Risk of Electrical Shock, Fire, or
Injury to Persons
WARNING ELECTRICAL SHOCK HAZARD
• Disconnect and lock out power before servicing.
• Discharge all capacitors before servicing.
• Use compressor with grounded system only.
• Molded electrical plug must be used when required.
• Refer to original equipment wiring diagrams.
• Electrical connections must be made by qualified electrical
personnel.
• Failure to follow these warnings could result in serious
personal injury.
PRESSURIZED SYSTEM HAZARD
• System contains refrigerant and oil under pressure.
• Remove refrigerant from both the high and low compressor side
before removing compressor.
• Never install a system and leave it unattended when it has no
charge, a holding charge, or with the service valves closed without
electrically locking out the system.
• Use only approved refrigerants and refrigeration oils.
• Personal safety equipment must be used.
• Failure to follow these warnings could result in serious
personal injury.
BURN HAZARD
• Do not touch the compressor until it has cooled down.
• Ensure that materials and wiring do not touch high temperature
areas of the compressor.
• Use caution when brazing system components.
• Personal safety equipment must be used.
• Failure to follow these warnings could result in serious
personal injury or property damage.
CAUTION COMPRESSOR HANDLING
• Use the appropriate lifting devices to move compressors.
• Personal safety equipment must be used.
• Failure to follow these warnings could result in personal
injury or property damage.
Safety Statements
• Refrigerant compressors must be employed only for their
intended use.
• Only qualified and authorized HVAC or refrigeration personnel
are permitted to install commission and maintain this
equipment.
• Electrical connections must be made by qualified electrical
personnel.
• All valid standards and codes for installing, servicing, and
maintaining electrical and refrigeration equipment must be
observed.
WARNING
WARNING
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INTRODUCTION
This bulletin describes the operating characteristics, design
features, and application requirements for all Copeland Scroll™
compressors for refrigeration applications using CO2 (R-744) for a
subcritical operation. For additional information, please refer to
the online product information accessible from the Emeson website
at Emerson.com/OPI. Increasing environmental concerns about the
potential direct emissions from HFC-based refrigeration systems
into the atmosphere have led system designers to revisit
refrigerant R-744 (CO2). In comparison with HFC refrigerants, the
specific properties of CO2 require changes in the design of the
refrigeration system. The ZO range of Copeland Scroll compressors
has been designed to exploit the characteristics of CO2
refrigeration systems. The efficiency, reliability and liquid
handling advantages of Copeland Scroll technology make it ideal for
these applications. The comparably high pressure level and
thermodynamic properties of the refrigerant CO2 have driven system
designers towards low temperature cascade systems, where CO2 is
used as a direct expanding refrigerant in the low temperature
stage. In these subcritical cascade applications, the CO2
compressor in the low temperature stage is still exposed to
pressure levels higher than in standard HFC-based systems. However,
they are limited to pressure levels similar to those already known
from air-conditioning applications with refrigerant R-410A. An HFC
refrigerant is typically used in the medium temperature stage of
the cascade system. The challenges for CO2 compressors compared to
HFC compressors lie in the high pressure levels, the higher mass
flow for a given displacement, and designing for proper
lubrication. In terms of mechanical strength, ZO scroll compressors
benefit from many years of experience with R-410A air-conditioning
compressors, which operate at similar pressure levels as CO2
compressors.
CO2 FOR LOW TEMPERATURE APPLICATIONS
SUB-CRITICAL DX SYSTEM
Figure 1 at the end of this bulletin shows a cascade system
diagram with HFC refrigerant for the high side and sub-critical CO2
for the low stage refrigerant. Nomenclature
The model designation contains the following technical
information about the compressor:
ZO D 34 K 3 E - TFD - 269 Z = Compressor family: Scroll O =
Refrigerant: R744, subcritical operation D= Digital Model; Blank=
Standard Model 34K = Nominal Capacity (kBTU/hr) 3 = Model variation
E = Oil type: POE oil TFD = Electrical Description:
T= Three Phases F= Internal Inherent Motor Protection 5,7,D,E=
Nominal Voltage Range
269 = Bill of material Please refer to Online Product
Information at Emerson.com/OPI for details. Refer to Table 1 for a
detailed list of ZO Family Models.
Approved Oils & Refrigerants
Recommended quality for carbon dioxide purity grade is 4.0 [(≥
99.99 %) H2O≤10ppm, O2≤10ppm, N2≤50ppm] or higher. Emkarate RL 68
HB is approved for new and service applications. Oil recharge
values can be taken from Copeland Scroll™ compressors brochures or
Copeland® brand Products Selection Software.
The compressor superheat at suction should be controlled such
that it is always above 36°F (20K) to avoid oil dilution in the
compressor but low return gas temperature enough to keep the
compressor discharge temperature below 250°F (121.1°C), especially
at high compressor ratios (high condensing and low evaporating
temperatures).
Note: A separate heat-exchanger may be required
to maintain the recommended superheat.
Refer to Table 2 for reference. Mounting Parts
Specially designed rubber grommets are available for
mounting (Kit 527-0157-00). These grommets are
formulated from a high durometer material specifically
designed for refrigeration applications. The high
durometer limits the compressors motion thereby
minimizing potential problems of excessive tubing
stress. Sufficient isolation is provided to prevent
CAUTION
http://www.emerson.com/OPIhttp://www.emerson.com/opi
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vibration from being transmitted to the mounting
structure. The use of standard soft grommets is not
recommended.
Refer Figure 2 for details.
Safety Relief Valves
In a closed system filled with CO2 the pressure can rise
above 725 psig (50 Bar) under some ambient
conditions. The system must be equipped with safety
relief valves to ensure that the compressor’s low side
and high side pressures are not exceeded (see below).
If the unit is shut down for service or other reasons, the
pressure will rise due to ambient heat. To prevent the
loss of charge at shut down through the relief valves, it
is recommended to provide additional cooling to keep
the pressure below the maximum standstill pressure of
the suction side. This can be achieved using a small
auxiliary condensing unit connected to an
uninterruptable power supply, that removes heat from
the R744 liquid receiver. The auxiliary condensing unit
will not be sufficient to maintain the low-stage system
below the Maximum Allowable Operation Pressure if
there is a load from the evaporators.
Refer to ANSI/ASHRAE Standard 15-2016, Section 9.7.5 and
ANSI/ASHRAE 15 appendix C-2016,. ZO Maximum Operating pressures
Suction side 500 psig (34.5 Bar)
Discharge side 625 psig (43.1 Bar)
The requirements for Copeland Scroll compressors with CO2 per
Underwriters Laboratory (UL) state that a system with a CO2
compressor must be installed with an approved suction pressure
relief valve. ASME high-pressure relief valves are the only valves
currently approved for use with the Copeland Scroll CO2 models. The
installation of the above valve must meet the following
criteria:
1. There must be an open flow path from the compressor suction
sump to the relief valve. This is accomplished by connecting the
relief valve to the correct port on the suction Rotalock valve.
This port is open to the compressor sump no matter what position
the valve stem is located. The relief valve itself can be remotely
located as long as the path from compressor suction sump and the
valve is always open.
2. This flow path cannot be shut off in any way by a valve.
Figure 4 represents the correct (a) and incorrect (b) way to
apply the pressure relief valve. Failure to apply the high-pressure
relief valve correctly will void any UL approval of the system. The
high-pressure relief valve should be located such that the path
between the valve and the low side of the compressor is always open
and cannot be shut off in any way by a valve. Note that the valve
opens only once and must be replaced if it opens. A 500 psig (34.5
Bar) high-pressure relief valve kit is shipped with the compressor.
Contact Application Engineering for alternative pressure relief
valves. ZO compressors have Rotalock valve fittings. Rotalock
shut-off valves are available for the suction as well as discharge
side. Using either straight or angled adaptors provides a way to
convert a Rotalock into a brazing connection.
Tightening Torques
Torque Lbs
Rotalock 1"-1 UNF 60-70 ft.lb.
Rotalock 1"1/4-12 UNF 75-85 ft.lb
High-Pressure Safety Controls
A CO2 approved ASME safety pressure relief valve(s)
with a setting of 500 psig (34.5 Bar) is required to be
pre-installed for standstill conditions.
All sections that can be isolated in the system must have relief
valves pre-installed by the system manufacturer with a 500 psig
(34.5 Bar) setting. These high-pressure cut-outs should have a
manual reset feature. Additional Requirements:
Low Pressure Cut-Out on Suction Side: 80 psig (5.5 bar)
High Pressure Cut-Out on Discharge Side: 625 psig (43.1 Bar)
Discharge Temperature Protection
External discharge line thermostat 998-7022-02
Active Oil Management
An OMC CO2 electronic oil level management system should be used
that is suitable for both high and low
CAUTION
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pressure oil management systems. The differential pressure
required for sufficient oil flow from the oil reservoir to the
compressor crankcase depends upon the system. However, 20 psig (1.4
Bar) can be used as a minimum pressure differential value. Refer to
Figure 3 and Table 4 For more details about OMB-CO2 Oil Management
Devices scan the QR codes below or follow the links available.
- Emerson OMC Video
- Emerson OMC Specification Sheet
https://climate.emerson.com/documents/omc-specification-sheet-en-us-3584550.pdf
- OMB/C Instructions
https://climate.emerson.com/documents/omb-c--pa-00388-en-4858298.pdf
- OMB Adapter Instruction Sheet
https://climate.emerson.com/documents/omb-adapter-instructions-en-4924792.pdf
Accumulators
Irrespective of system charge, oil dilution may occur if large
amounts of liquid refrigerant repeatedly flood back to the
compressor during normal running cycles, defrost, and varying
loads. If adequate Compressor Superheat cannot consistently be
maintained at minimum of 36°F (20K) an accumulator may be required,
as well as the addition of liquid to suction heat exchanger or
other means as assuring 36°F (20K) Superheat. Screens
The use of screens finer than 30 x 30 mesh (0.6 mm openings)
anywhere in the system should be avoided with these compressors.
Field experience has shown that finer mesh screens used to protect
expansion valves, capillary tubes, or accumulators can become
temporarily or permanently plugged with normal system debris and
block the flow of either oil or refrigerant to the compressor. Such
blockage can result in compressor failure. Mufflers
External mufflers, normally applied to piston compressors in the
past, may not be required for Copeland Scroll compressors.
Individual system tests should be performed to verify acceptability
of sound performance. If adequate attenuation is not achieved, use
a muffler with a larger cross-sectional area to inlet area ratio. A
ratio of 20:1 to 30:1 is recommended. A hollow shell muffler will
work quite well. Locate the muffler 6-18 inches from the compressor
for the most effective operation. The farther the muffler is placed
from the compressor within these ranges, the more effective. Choose
a muffler with a length of 2-6 inches.
https://climate.emerson.com/documents/omc-specification-sheet-en-us-3584550.pdfhttps://climate.emerson.com/documents/omc-specification-sheet-en-us-3584550.pdfhttps://climate.emerson.com/documents/omb-c--pa-00388-en-4858298.pdfhttps://climate.emerson.com/documents/omb-c--pa-00388-en-4858298.pdfhttps://climate.emerson.com/documents/omb-adapter-instructions-en-4924792.pdfhttps://climate.emerson.com/documents/omb-adapter-instructions-en-4924792.pdf
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Electrical Connection
The compressor terminal box has a wiring diagram on
the inside of its cover. Before connecting the
compressor, ensure the supply voltage, the phases and
the frequency match the nameplate data. Refer to
Figure 5 for details.
The terminal box is IP21 for all models from ZO21K* to ZO104K*.
The ZO Scroll compressors have three-phase induction motors
connected in star. Copeland Scroll compressors, like several other
types of compressors, will only compress in one rotational
direction. 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. Verification 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 specific system or installation, connecting properly phased power
leads to the identified compressor electrical (Fusite™) terminals
will maintain the proper rotational direction (see Figure 7). All
three phase scrolls will continue to run in reverse until the
internal overload protector opens or the phasing is corrected.
Crankcase Heaters
A crankase heater is always required. The crankcase heater ust
be turned on a minimum of 12 hours prior to starting the compressor
and must remain energized during the compressor off cycle. See
Table 3 for reference.
Motor Protection
For the ZO range of compressors, conventional inherent internal
line break motor protection is provided. Operating Envelope
Figure 6 at the end of this bulletin shows the CO2 cascade
operating envelope in relation to R-410A and R-404A. Charging
Procedure
Do not operate compressor without enough system charge to
maintain at least 87 psig (6 Bar) suction pressure.
Do not operate with a restricted suction.
Do not operate with the low-pressure cut-out bridged.
Vapor initial charge should be 145 PSIG (10 Bar). Do not allow a
pressure under 87 psig (6 Bar), otherwise it might cause CO2
solidification and blocked valves or pipes and consequently, the
scrolls may overheat and cause early drive bearing damage. Do not
use the compressor to test the opening set point of the
high-pressure cut-out. Bearings are susceptible to damage before
they have had several hours of normal running in. Ensure charging
equipment is approved for at least 1300 psig (89.6 Bar). The system
should be charged through the liquid-receiver shut-off valve or
through a valve in the liquid line. The use of a filter drier in
the charging line is highly recommended. Because there may be
several valves in the system it is recommended to charge on both
the high and low sides simultaneously to ensure a positive
refrigerant pressure is present in the compressor before it runs.
The majority of the charge should be placed in the high side of the
system to prevent bearing washout during first-time start. Deep
Vacuum Operation
Copeland Scroll compressors 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. Low suction pressures will
result in
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overheating of the scrolls and permanent damage to the
compressor drive bearing. ZO scrolls incorporate internal low
vacuum protection, the floating seal unloads when the pressure
ratio exceeds approximately 10:1.
Shell Temperature
The top shell and discharge line can briefly but repeatedly
reach temperatures above 350°F (176.7 °C) if the compressor cycles
on its internal protection devices. This only happens under rare
circumstances and can be caused by the failure of system components
such as the condenser or evaporator fan or loss of charge and
depends upon the type of expansion control. Care must be taken to
ensure that wiring or other materials that could be damaged by
these temperatures do not come in contact with the shell. Pump Down
Cycle and Parallel Rack Application
A pump down cycle for control of refrigerant migration may be
used in conjunction with a crankcase heater when the compressor is
located so that cold air blowing over the compressor makes the
crankcase heater ineffective. If a pump down cycle is used on a
parallel rack system, a separate external check valve must be
added. The scroll discharge check valve is designed to stop
extended reverse rotation and prevent high-pressure gas from
leaking rapidly into the low side after shut off. The check valve
will in some cases leak more than reciprocating compressor
discharge reeds, normally used with pump down, causing the scroll
compressor to recycle more frequently. Repeated short-cycling of
this nature can result in a low oil situation and consequent damage
to the compressor. The low-pressure control differential has to be
reviewed since a relatively large volume of gas will re-expand from
the high side of the compressor into the low side on shutdown. Low
Pressure Safety Control
Never set the low-pressure control to shut off outside of the
operating envelope. To prevent the compressor from running into
problems during such faults as loss of charge or partial blockage,
the control should not be set lower than -60°F (-51.1°C) equivalent
suction pressure (80 PSIG, 5.51 bar) below the lowest design
operating point.
Minimum Run Time
Emerson recommends a maximum of 10 starts per hour. There is no
minimum off time because scroll compressors start unloaded, even if
the system has
unbalanced pressures. The most critical consideration is the
minimum run time required to return oil to the compressor after
start-up. To establish the minimum run time, obtain a sample
compressor equipped with a sight tube (available from Emerson
Climate Technologies) and install it in a system with the longest
connecting lines that are approved for the system. The minimum on
time becomes the time required for oil lost during compressor
start-up to return to the compressor sump and restore a minimal oil
level that will ensure oil pick-up through the crankshaft. Cycling
the compressor for a shorter period than this, for instance to
maintain very tight temperature control, will result in progressive
loss of oil and damage to the compressor.
ASSEMBLY LINE PROCEDURES
Installing the Compressor
Copeland Scroll compressors leave the factory dehydrated and
with a positive dry air charge. Plugs should not be removed from
the compressor until the compressor has had sufficient time to warm
up if stored outside and is ready for assembly in the unit. The
suggested warm up time is one hour per 4°F (2K) difference between
outdoor and indoor temperature. It is suggested that the larger
suction plug be removed first to relieve the internal pressure.
Removing the smaller discharge plug could result in a spray of oil
out of this fitting since some oil accumulates in the head of the
compressor after Emerson’s run test. The inside of both fittings
should be wiped with a lint free cloth to remove residual oil prior
to brazing. A compressor containing POE oil should never be left
open longer than 5 minutes. Assembly Line Brazing Procedure
Following are the proper procedures for brazing the suction and
discharge lines to a scroll compressor. It is important to flow
nitrogen through the system while brazing all joints during the
system assembly process. Nitrogen displaces the air and prevents
the formation of copper oxides in the system. If allowed to form,
the copper oxide flakes can later be swept through the system and
block screens such as those protecting capillary tubes, thermal
expansion valves, and accumulator oil return holes. Any blockage of
oil or refrigerant may damage the compressor resulting in failure.
New Installations
• The copper-coated steel suction tube on scroll compressors can
be brazed in approximately the same manner as any copper tube.
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• Recommended brazing materials: Any SIL-FOS® material is
recommended, preferably with a minimum of 5% silver. However, 0%
silver is acceptable.
• Be sure suction tube fitting I.D. and suction tube O.D. are
clean prior to assembly. If oil film is present wipe with denatured
alcohol, Dichloro-Trifluoroethane or other suitable solvent.
• Using a double-tipped torch apply heat in Area 1. As tube
approaches brazing temperature, move torch flame to Area 2.
Scroll Suction Tube Brazing
• Heat Area 2 until braze temperature is attained, moving torch
up and down and rotating around tube as necessary to heat tube
evenly. Add braze material to the joint while moving torch around
joint to flow braze material around circumference.
• After braze material flows around joint, move torch to heat
Area 3. This will draw the braze material down into the joint. The
time spent heating Area 3 should be minimal.
• As with any brazed joint, overheating may be detrimental to
the final result.
‘Hipot’ (AC High Potential) Testing
Copeland Scroll compressors are configured with the motor down
and the pumping components at the top of the shell. As a result,
the motor can be immersed in refrigerant to a greater extent than
hermetic reciprocating compressors when liquid refrigerant is
present in the shell. In this respect, the scroll is more like
semi-hermetic compressors that have horizontal motors partially
submerged in oil and refrigerant. When Copeland Scroll compressors
are hipot tested with liquid refrigerant in the shell, they can
show higher levels of leakage current than compressors with the
motor on top. This phenomenon can occur with any compressor when
the motor is immersed in refrigerant. The level of current leakage
does not present any safety issue. To lower the current leakage
reading, the system
should be operated for a brief period of time to redistribute
the refrigerant to a more normal configuration and the system hipot
tested again. See AE4-1294 for megaohm testing recommendations.
Under no circumstances should the hipot test be performed while the
compressor is under a vacuum.
MAINTENANCE AND REPAIR
Service Procedures
Copeland Scroll Compressor Functional Check: A functional
compressor test during which the suction service valve is closed to
check how low the compressor will pull the suction pressure is not
a good indication of how well a compressor is performing. Such a
test will damage a scroll compressor in a few seconds. The
following diagnostic procedure should be used to evaluate whether a
Copeland Scroll compressor is functioning properly:
1. Proper voltage to the unit should be verified.
2. Determine if the internal motor overload has opened or if an
internal motor short or ground fault has developed. If the internal
overload has opened, the compressor must be allowed to cool
sufficiently to allow it to reset.
3. Check that the compressor is correctly wired.
4. Proper indoor and outdoor blower/fan operation should be
verified.
5. With service gauges connected to suction and discharge
pressure fittings, turn on the compressor. If suction pressure
falls below normal levels the system is either low on charge or
there is a flow blockage in the system.
6. Three phase compressors – If suction pressure does not drop
and discharge pressure does not rise to normal levels, reverse any
two of the compressor power leads and reapply power to make sure
the compressor was not wired to run in reverse. If pressures still
do no move to normal values, either the reversing valve (if so
equipped) or the compressor is faulty. Reconnect the compressor
leads as originally configured and use normal diagnostic procedures
to check operation of the reversing valve.
7. To test if the compressor is pumping properly, the compressor
current draw must be compared to published compressor performance
curves using the operating pressures and voltage of the
https://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1294.pdf
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system. If the measured average current deviates more than
+/-20% from published values, a faulty compressor may be indicated.
A current imbalance exceeding 20% of the average on the three
phases of a three-phase compressor should be investigated further.
A more comprehensive trouble-shooting sequence for compressors and
systems can be found in Section H of the Emerson Climate
Technologies Electrical Handbook, Form No. 6400.
8. Before replacing or returning a compressor, be certain that
the compressor is actually defective. As a minimum, recheck
compressors returned from the field in the shop or depot by testing
for a grounded, open or shorted winding and the ability to start.
The orange tag in the service compressor box should be filled out
and attached to the failed compressor to be returned. The
information on this tag is captured in our warranty data base.
Compressor Replacement After a Motor Burn
In the case of a motor burn, the majority of contaminated oil
will be removed with the compressor. The rest of the oil is cleaned
with the use of suction and liquid line filter driers. A 100%
activated alumina suction filter drier is recommended but must be
removed after 72 hours. See AE24-1105 for clean up procedures and
AE11-1297 for liquid line filter-drier recommendations. It is
highly recommended that the suction accumulator be replaced if the
system contains one. This is because the accumulator oil return
orifice or screen may be plugged with debris or may become plugged
shortly after a compressor failure. This will result in starvation
of oil to the replacement compressor and a second failure. The
system contactor should be inspected for pitted/burnt
contacts and replaced if necessary. It is highly recommended
that the run capacitor be replaced when a single phase compressor
is replaced. General Guidelines and More Information
For general Copeland Scroll compressor and CO2 refrigerant
please log in to Online Product Information at Emerson.com/OPI,
refer to the Application Engineering bulletins listed below, or
contact your Application Engineer.
AE4-1294 Megaohms Values of Copeland® Compressors
AE24-1105 Principles of Cleaning Refrigeration Systems
AE11-1297 Liquid Line Filter-Driers
AE4-1396 Application Guidelines for Copeland™ Semi-Hermetic
Compressors for Transcritical CO2 Applications
Commercial CO2 Refrigeration Systems Guide
https://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1105.pdfhttps://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1297.pdfhttp://www.emerson.com/OPIhttps://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1294.pdfhttps://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1105.pdfhttps://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1297.pdfhttps://opi.emersonclimate.com/CPID/GRAPHICS/Types/AEB/ae1396.pdfhttp://www.emersonclimate.com/Documents/FlowControls/pdf/2015CO2-07-R2-Commerical-CO2-Handbook-%28Sept2015%29.pdf
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Table 2 Qualified Refrigerants and Oils
Qualified Refrigerants CO₂ (R-744)
Copeland™ Standard Oil Emkarate RL 68 HB
Servicing Oil Emkarate RL 68 HB
Note: Refer to form 93-11 for the latest approved
refrigerants and lubricants for Copeland products.
Table 3 Crankcase Number Kits
Model OEM Part # Description Aftermarket #
ZO21K5E
018-0094-00 240V, 40W 918-0052-00
018-0094-01 120V, 40W 918-0052-01
018-0094-03 480V, 40W, 21.25" Lead Length 918-0052-03
018-0094-04 575V, 40W, 21.25" Lead Length 918-0052-04
ZO34K3E ZOD34K3E ZO45K3E ZO58K3E
ZOD58K3E ZO88KCE
ZO104KCE ZOD104KCE
018-0095-00 240V, 70W, 21" Lead Length 518-0024-06
018-0095-01 480V, 70W, 21" Lead Length 518-0024-07
018-0095-02 575V, 70W, 21" Lead Length 518-0024-08
018-0095-03 240V, 70W, 32" Lead Length 995-0018-00
018-0095-04 240V, 70W, 48” Lead Length 918-0043-00
018-0095-05 480V, 70W, 48” Lead Length 918-0043-01
018-0095-06 575V, 70W, 48" Lead Length 918-0043-02
018-0095-07 120V, 70W, 48" Lead Length 918-0043-07
018-0095-08 400V, 70W, 48" Lead Length -
018-0095-09 277V, 70W, 21" Lead Length -
Table 1 ZO Family Models
Model Nominal
Horse-power Displacement
CFH Capacity BTU/hr
EER Weight lb(kg)
Motors
TF5 200/230-3Ø-60Hz 200/220-3Ø-50Hz
TF7 380-3Ø-60Hz
TFD 460-3Ø-60Hz
480/420-3Ø-50Hz
TFE 575-3Ø-60Hz
ZO21K5E 1.3 112 20,800 15 49 (22) X X X
ZO34K3E 2 172 32,000 15 60 (27) X X X X
ZOD34K3E 2 172 32,000 15 60 (27) X X X X
ZO45K3E 2.5 228 42,700 17 62 (28) X X X
ZO58K3E 3.5 291 55,000 17 65 (29) X X X X
ZOD58K3E 3.5 291 55,000 17 65 (29) X X X X
ZO88KCE 5 431 85,300 16 88 (40) X X X X
ZO104KCE 6 498 95,500 16 90 (41) X X X X
ZOD104KCE 6 498 95,500 16 90 (41) X X X X
Capacity with R-744 at -31°F (-35°C) evap, 14°F (-10°C) cascade
cond, 5°F (-15°C) RG, 14°F (-10°C) liquid
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Table 4 OMC CO2 Specifications
SPECIFICATIONS OMC CO2
Maximum Working Pressure (MWP) 1885 PSIG (130 Bar)
Solenoid min/max OPD 1/1450 psig
Supply Voltage 120 V or 220-240V, 50/60 Hz
Solenoid Coil EMF
Current Consumption 0.15 Amp (120V), 0.07 Amp (220-240V)
Time Delay for Low Level Signal 10 seconds
Time Delay After Setpoint Recovery 5 seconds
Alarm Delay Time (Including Alarm Contact)
120 seconds
Alar Switch SPDT
Alarm Contact Rating 10A @ 120VAC 50/60Hz, 5A @ 250VAC 50/60 Hz,
3A@ 30 VDC
Refrigerant Temperature -40° to 180°F (-40°C to 82.2°C)
Maximum
Ambient Temperature - Storage -40° to 120°F (-40°C to 48.9°C)
Maximum
Ambient Temperature - Intermittent Duty
-40° to 120°F (-40°C to 48.9°C) Maximum
Oil Supply Fitting 1/4" Male SAE (Brass)
Figure 1 CO2 Low Temp. Subcritical DX System
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Figure 2 Specially designed rubber rommets Kit # 527-0157-00
Figure 3 Oil Management Control OMC-CO2
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Figure 4 Suction Side Pressure Relief Valve Requirements
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Figure 5 Three Phase Power Circuit
Figure 6 - ZO Compressor Operating Envelope
Figure 7 Compressor Electrical Connection
The contents of this publication are presented for informational
purposes only and are not to be construed as warranties or
guarantees, express or implied,
regarding the products or services described herein or their use
or applicability. Emerson Climate Technologies, Inc. and/or its
affiliates (collectively
"Emerson"), as applicable, reserve the right to modify the
design or specifications of such products at any time without
notice. Emerson does not assume
responsibility for the selection, use or maintenance of any
product. Responsibility for proper selection, use and maintenance
of any Emerson product
remains solely with the purchaser or end user.