Emerson Copeland ZH04KCU Instruction Manual

Copeland™Scroll Compressors
for R290 Applications
ZH04KCU to ZH13KCU
Application Guidelines

AGL_HP_ST_ZHKCU_EN_Rev01
About these guidelines ...............................................................................................1
1Safety instructions...........................................................................................1
1.1 Icon explanation............................................................................................................... 1
1.2 Safety statements ............................................................................................................ 2
1.3 General instructions......................................................................................................... 2
2Product description .........................................................................................3
2.1 Compressor range ........................................................................................................... 3
2.2 Nomenclature................................................................................................................... 3
2.3 BOM variations ................................................................................................................ 3
2.4 Application range ............................................................................................................. 4
2.4.1 Qualified refrigerant and oil.................................................................................. 4
2.4.2 Application limits................................................................................................... 4
2.4.3 PED category and maximum allowable pressure PS .......................................... 4
2.5 Dimensions ...................................................................................................................... 5
3Installation........................................................................................................6
3.1 Compressor handling....................................................................................................... 6
3.1.1 Transport and storage.......................................................................................... 6
3.1.2 Positioning and securing...................................................................................... 6
3.1.3 Installation location............................................................................................... 6
3.2 Mounting parts ................................................................................................................. 7
3.3 Brazing procedure............................................................................................................ 7
3.3.1 General brazing procedure................................................................................... 7
3.3.2 Brazing procedure for ZH*KCU compressors in parallel applications ................. 8
3.4 Pressure safety controls .................................................................................................. 8
3.4.1 High-pressure protection...................................................................................... 8
3.4.2 Low-pressure protection....................................................................................... 9
3.5 System protection for operation below atmospheric pressure......................................... 9
3.6 Crankcase heater........................................................................................................... 10
3.7 Discharge gas temperature protection........................................................................... 11
3.7.1 Excessive discharge gas temperatures ............................................................. 11
3.7.2 Discharge line thermostat................................................................................... 12
3.8 Internal pressure relief valve.......................................................................................... 13
3.9 Discharge check valve................................................................................................... 13
3.10 Filter screens ................................................................................................................. 13
3.11 Mufflers .......................................................................................................................... 13
3.12 Sound shell .................................................................................................................... 13
3.13 Insulation material.......................................................................................................... 13
3.14 Reversing valves............................................................................................................ 14
3.15 Sound and vibration....................................................................................................... 14
3.16 Compressor oil return, oil balancing, refrigerant floodback and oil dilution tests .......... 15

AGL_HP_ST_ZHKCU_EN_Rev01
3.17 Suction line accumulators.............................................................................................. 16
4Electrical connection.....................................................................................17
4.1 General recommendations............................................................................................. 17
4.2 Electrical installation ...................................................................................................... 17
4.3 Terminal box .................................................................................................................. 19
4.3.1 Terminal box –IP54........................................................................................... 20
4.3.2 Terminal box –IP65........................................................................................... 20
4.4 Motor insulation.............................................................................................................. 21
4.5 Motor protection............................................................................................................. 21
4.6 High-potential testing ..................................................................................................... 22
5Starting up & operation..................................................................................23
5.1 Strength-pressure test ................................................................................................... 23
5.1.1 Compressor strength-pressure test.................................................................... 23
5.1.2 System strength-pressure test ........................................................................... 23
5.2 Compressor tightness test ............................................................................................. 24
5.3 System evacuation......................................................................................................... 24
5.4 Preliminary checks –Pre-starting.................................................................................. 24
5.5 Charging procedure ....................................................................................................... 25
5.6 Run-in time..................................................................................................................... 25
5.7 Initial start-up ................................................................................................................. 25
5.8 Rotation direction........................................................................................................... 25
5.9 Starting sound................................................................................................................ 26
5.10 Deep vacuum operation................................................................................................. 26
5.11 Shell temperature........................................................................................................... 26
5.12 Pumpdown cycle............................................................................................................ 26
5.13 Minimum run time .......................................................................................................... 27
5.14 Shut-off sound................................................................................................................ 27
5.15 Supply frequency and voltage ....................................................................................... 27
5.16 Oil level .......................................................................................................................... 27
6Maintenance & repair.....................................................................................29
6.1 Qualification of workers.................................................................................................. 29
6.2 Preparation and work procedure ................................................................................... 30
6.3 Disassembling system components .............................................................................. 30
6.4 Replacing a compressor................................................................................................ 30
6.4.1 Compressor replacement................................................................................... 30
6.4.2 Start-up of a new or replacement compressor................................................... 31
6.4.3 Compressor return procedure............................................................................ 31
6.5 Exchanging the refrigerant............................................................................................. 32
6.6 Lubrication and oil removal............................................................................................ 32
6.7 Oil additives ................................................................................................................... 33

AGL_HP_ST_ZHKCU_EN_Rev01
7Troubleshooting.............................................................................................34
8Dismantling & disposal..................................................................................37
9References......................................................................................................37
Appendix 1: Tightening torques...............................................................................38
DISCLAIMER ..............................................................................................................38

AGL_HP_ST_ZHKCU_EN_Rev01 1
About these guidelines
The purpose of these guidelines is to provide guidance in the application of Copeland™scroll
compressors in users’ systems. They are intended to answer the questions raised while designing,
assembling and operating a system with these products.
Besides the support they provide, the instructions listed herein are also critical for the proper and
safe functioning of the compressors. The performance and reliability of the product may be impacted
if the product is not used according to these guidelines or is misused.
These application guidelines cover stationary applications only. For mobile applications, please
contact the Application Engineering department at Emerson as other considerations may apply.
1 Safety instructions
Copeland scroll compressors are manufactured according to the latest relevant European, UK and
US safety standards. Particular emphasis has been placed on the user’s safety.
ZH*KCU compressors are intended for installation in systems in accordance with the following
directives and regulations:
Machinery Directive MD 2006/42/EC
Supply of Machinery (Safety) Regulation 2016
Pressure Equipment Directive PED 2014/68/EU
Pressure Equipment (Safety) Regulation 2008
Low Voltage Directive LVD 2014/35/EU
Electrical Equipment (Safety) Regulation 2016
They may be put to service only if they have been installed in systems according to instructions and
conform to the corresponding provisions of legislation.
In order to keep the system compliant with the ATEX Directive 99/92/EC, all accessories to be fitted
on the compressor, eg, oil level regulator, crankcase heater, discharge line thermostat, shall comply
with the ATEX Directive 2014/34/EU Zone 2. If one of these accessories does not comply, the
complete system will lose its compliance with the ATEX Directive 99/92/EC and therefore can be
operated only in a non-flammable environment.
NOTE: Only dedicated compressors are allowed to be used with flammable refrigerants.
Emerson marks all compressors that are qualified for flammable refrigerants with a sticker
indicating the usage of such refrigerants. Systems using flammable refrigerants must be
executed correctly while observing safety rules, as specified in corresponding safety
standards such as, but not limited to EN 378. They must comply with any and all applicable
legislation and regulations. Ensuring compliance remains the user’s responsibility.
The Material Safety Datasheet (MSDS) of the refrigerant shall be considered –please check the
document provided by the gas supplier.
These instructions shall be retained throughout the lifetime of the compressor.
You are strongly advised to follow these safety instructions.
1.1 Icon explanation
WARNING
This icon indicates instructions to avoid
personal injury and material damage.
Fire hazard
This icon indicates a risk of flammable
atmosphere.
High voltage
This icon indicates operations with a
danger of electric shock.
CAUTION
This icon indicates instructions to avoid
property damage and possible personal
injury.
Danger of burning or frostbite
This icon indicates operations with a
danger of burning or frostbite.
IMPORTANT
This icon indicates instructions to avoid
malfunction of the compressor.
Explosion hazard
This icon indicates operations with a
danger of explosion.
NOTE
This word indicates a recommendation for
easier operation.
Danger of explosive atmosphere
This icon indicates a risk of explosive
atmosphere.

2 AGL_HP_ST_ZHKCU_EN_Rev01
1.2 Safety statements
▪Refrigerant compressors must be employed only for their intended use. The system has
to be labelled according to the applicable standards and legislation.
▪Only qualified and authorized RACHP (refrigeration, air conditioning and heat pump)
personnel are permitted to install, commission and maintain this equipment. Only
competent personnel (as specified in EN 13313) qualified for flammable refrigerant
handling are permitted to commission, initiate and maintain the compressor/refrigeration
systems; non-trained personnel, including the user, are not allowed to do so and must call
on an expert.
▪The maximum refrigerant charge is specified in standards such as, but not limited to
EN 378, EN 60335-2-40 and EN 60335-2-89. The system designer shall implement all safety
measures defined by the applicable standards and the maximum refrigerant charge shall
not be exceeded.
▪When planning and building systems with flammable refrigerants, a risk assessment and
corresponding precautions for risk mitigation must be taken by the system designer.
Special attention must be paid to flammability when dealing with A3 refrigerants.
▪If a flammable or explosive atmosphere is detected, immediately take all necessary
precautions to mitigate the risk as determined in the risk assessment.
▪Electrical connections must be made by qualified electrical personnel.
▪All valid standards for connecting electrical and refrigeration equipment must be
observed.
▪The national legislation and regulations regarding personnel protection must be observed.
Use personal safety equipment. Safety goggles, gloves, protective
clothing, safety boots and hard hats should be worn where necessary.
1.3 General instructions
WARNING
Pressurized system! Serious personal injuries and/or system
breakdown! Accidental system start before complete set-up must be avoided.
Never leave the system unattended without locking it out electrically when it is
under vacuum and has no refrigerant charge, when it has a holding charge of
nitrogen, or when the compressor service valves are closed.
WARNING
System breakdown! Personal injuries! Only approved refrigerants and
refrigeration oils must be used.
WARNING
High shell temperature! Burning! Do not touch the compressor until it has
cooled down. Ensure that other materials in the area of the compressor do not
come into contact with it. Lock and mark accessible sections.
CAUTION
Overheating! Bearing damage! Do not operate compressor without
refrigerant charge or without it being connected to the system.
CAUTION
Contact with refrigerant oil! Material damage! Polyolester (POE) lubricants
must be handled carefully and the proper protective equipment (gloves, eye
protection, etc.) must be used at all times. POE must not come into contact
with any surface or material that it might damage, including, without limitation,
some polymers, eg, PVC/CPVC and polycarbonate.
IMPORTANT
Transit damage! Compressor malfunction! Use original packaging. Avoid
collisions and tilting.

AGL_HP_ST_ZHKCU_EN_Rev01 3
2 Product description
2.1 Compressor range
These application guidelines cover Copeland scroll compressor models ZH*KCU for heat pump
applications.
Compressor
Heating
capacity (kW)
Motor
ZH04KCU
4.41
PFZN/TFDN
ZH06KCU
6.02
PFZN/TFDN
ZH08KCU
7.53
PFZN/TFDN
ZH09KCU
8.76
PFZN/TFDN
ZH11KCU
10.85
PFZN/TFDN
ZH13KCU
12.70
TFDN
Evaporating temperature: -7 °C; condensing temperature: 50 °C; suction gas superheat: 10K; liquid sub-cooling:
4 K; frequency: 50 Hz
Table 1: ZH*KCU model overview for high-temperature applications
2.2 Nomenclature
The model designation contains the following technical information about the compressors:
Figure 1: Nomenclature
2.3 BOM variations
The BOM (bill of material) number at the end of the compressor designation indicates the different
compressor layouts and details. ZH*KCU compressor models are available in the following BOM
versions:
BOM
Suction & discharge
connections
T-Box
Mounting parts
Features
534
Brazing stub tubes
IP54
For single compressor use
Single compressor
434
Without
Tandem-ready
524
IP65
For single compressor use
Single compressor
424
Without
Tandem-ready
Table 2: BOM designation
Please refer to the Emerson price list for more details.
Compressors with BOM 524 and BOM 424 contain an IP65 terminal box, which complies with the
ATEX Directive 94/9/EC part II 3G. The compressor label conforms to the ATEX Directive
2014/34/EU specifications and to the harmonized standard series EN 60079.

4 AGL_HP_ST_ZHKCU_EN_Rev01
The ATEX marking for applications in gas explosive atmosphere Zone 2 locations is as follows:
▪ATEX Directive 94/9/EC part: II 3G
▪Standard part (EN 60079-0, EN 60079-15): Ex nA IIA T2
The Declaration of Conformity is available from the manufacturer upon request.
2.4 Application range
2.4.1 Qualified refrigerant and oil
Compressors
ZH04KCU to ZH13KCU
Qualified and approved
refrigerant
R290
Qualified oil (factory charged)
POE Hatcol 4467 (Ident Number 8410785)
Servicing oil
POE Hatcol 4467 (Ident Number 8410785)
Table 3: Qualified refrigerant and oil
Oil recharge values can be taken from the compressor nameplate or from Copeland Select software
available at www.climate.emerson.com/en-gb/tools-resources.
2.4.2 Application limits
CAUTION
Inadequate lubrication! Compressor breakdown! The superheat at the
compressor suction inlet must always be sufficient to ensure that no refrigerant
droplets enter the compressor. For a typical evaporator-expansion valve
configuration a minimum stable superheat of at least 10 K is required.
For application envelopes and technical data, please refer to Copeland Select software available at
www.climate.emerson.com/en-gb.
2.4.3 PED category and maximum allowable pressure PS
The nameplate of the compressor contains information about the maximum allowable pressure PS,
the minimum and maximum allowed temperature TS, the internal free volume and the fluid groups
of the refrigerants qualified for the compressor model range. Values are given for the two existing
pressure ranges on low- and high-pressure sides.
The PED category is assigned according to the Pressure Equipment Directive PED 2014/68/EU.
Requirements apply to the relevant pressure levels in the compressor when the product of "pressure
relative to the environment" by "related internal free volume" (P x V) exceeds given limits. When
calculating the PED category, the high- and low-pressure sides have to be calculated separately.
The highest of the calculation results is considered.
Compressor
PS
Low-pressure
side
PS
High-
pressure side
TS max.
Low-pressure
side
Internal free
volume
LP side (litres)
Internal free
volume
HP side (litres)
ZH04KCU
17 bar(g)
28 bar(g)
50 °C
4.1
0.5
ZH06KCU
17 bar(g)
28 bar(g)
50 °C
4.2
0.5
ZH08KCU
17 bar(g)
28 bar(g)
50 °C
4.3
0.5
ZH09KCU
17 bar(g)
28 bar(g)
50 °C
6.4
0.6
ZH11KCU
17 bar(g)
28 bar(g)
50 °C
6.4
0.6
ZH13KCU
17 bar(g)
28 bar(g)
50 °C
6.4
0.6
Table 4: Maximum allowable pressures, temperatures and internal free volumes
Additionally, a distinction must be made between refrigerants of fluid group 1 (flammable) and fluid
group 2 (non-flammable). The ZH*KCU compressors covered in these guidelines are released for
use with R290 which belongs to fluid group 1.
Compressor range
Refrigerant
Fluid group
PED category
ZH04KCU to ZH16KCU
R290
1
II
Table 5: PED category based on refrigerant and fluid group

AGL_HP_ST_ZHKCU_EN_Rev01 5
2.5 Dimensions
Figure 2: Dimensions - BOM versions 424 & 524 Figure 3: Dimensions - BOM versions 434 & 534
Model
BOM
A
B
C
D
E
F
G
H
J
K
L
o
ZH04KCU
534/434
364.4
338
245
168.85
69.6*
165.8
247.5
252.6
115.5
96.9
58.2
49
524/424
173.5
254.4
253
ZH06KCU
534/434
387
361
264
185.75
75.3*
165.8
247.5
252.6
115.5
96.9
58.2
49
524/424
193.4
254.4
253
ZH08KCU
534/434
400.8
375
277
198.43
75.3*
165.8
247.5
252.6
115.5
96.9
58.2
49
524/424
206.1
254.4
253
ZH09KCU
ZH11KCU
ZH13KCU
534/434
437.8
410
297
225.2
79.6*
185.5
260.6
255
124.7
103
62.1
44
524/424
442
223
265.6
254.4
Table 6: Compressor dimensions
NOTE: The connection in blue colour (see dimension E) is an additional brazing connection
for paralleling models (BOM versions 434 and 424).

6 AGL_HP_ST_ZHKCU_EN_Rev01
3 Installation
WARNING
High pressure! Injury to skin and eyes possible! Be careful when opening
connections on a pressurized item.
3.1 Compressor handling
3.1.1 Transport and storage
WARNING
Risk of collapse! Personal injuries! Move compressors only with
appropriate handling equipment according to weight. Keep in the upright
position. Respect stacking loads according to Figure 4. Check the tilting
stability and if needed take action to ensure the stability of the stacked loads.
Keep the packaging dry at all times.
Respect the maximum number of identical packages which may be stacked on one
another, where "n" is the limiting number:
▪Transport: n = 1
▪Storage: n = 2
Figure 4: Maximum stacking loads for transport and storage
The compressor tilt angle should not exceed 30° during transport and handling. This will prevent oil
from exiting through the suction stub. A tilt angle of maximum 45° is allowed for a very short time.
Tilting the compressor more than 45° might affect its lubrication at start-up.
NOTE: The compressor is pre-charged with dry air to avoid any moisture contamination.
3.1.2 Positioning and securing
IMPORTANT
Handling damage! Compressor malfunction! Only use the lifting eyes
whenever the compressor requires positioning. Using discharge or suction
connections for lifting may cause damage or leaks.
The compressor should be kept vertical during handling.
The discharge connection plug should be removed first before pulling the suction connection plug to
allow the dry air pressure inside the compressor to escape. Pulling the plugs in this sequence
prevents oil mist from coating the suction tube making brazing difficult. The copper-coated steel
suction tube should be cleaned before brazing.
The plugs must be removed as late as possible before brazing so that the air humidity does not affect
the oil characteristics.
For ZH*KCU compressors, as oil might spill out of the suction connection located low on the shell,
the suction connection plug must be left in place until the compressor is set into the unit.
No object, eg, a swaging tool should be inserted deeper than 51 mm into the suction tube as it might
damage the suction screen and motor.
3.1.3 Installation location
These compressors shall be installed in Zone 2 locations, as defined by the ATEX directive, or in
non-hazardous atmospheres.
Ensure the compressors are installed on a solid level base. For single compressor applications, the
compressor tilt angle during operation should not exceed 15° to allow adequate lubrication. For
multiple-compressor parallel configurations, the compressors must be positioned completely
vertically on a totally horizontal surface or rail.

AGL_HP_ST_ZHKCU_EN_Rev01 7
3.2 Mounting parts
The compressors are designed to be mounted on vibration absorber grommets. The grommets
dampen the start-up surge of the compressor and minimise sound and vibration transmission to the
compressor base during operation. The metal sleeve inside is a guide designed to hold the grommet
in place. It is not designed as a load-bearing member, and application of excessive torque to the
bolts can crush the sleeve. Its inner diameter is approximately 8.5 mm to fit, eg, an M8 screw. The
mounting torque should be 13 ± 1 Nm. It is critically important that the grommet is not compressed.
If the compressors are mounted in tandem or used in parallel, then the hard mountings (bolt M9
5/16") are recommended. The mounting torque should be 27 ± 1 Nm.
See Copeland spare parts & accessories catalogue for reference.
Mounting parts ZH*KCU –Soft mountings
Figure 5: Mounting parts
3.3 Brazing procedure
WARNING
Air/flammable refrigerant mixture! Creation of a potentially flammable
atmosphere! Fire hazard! Remove all refrigerant before opening the system.
When working on a refrigerant-filled system, make sure to follow the safety
and working instructions given in Chapter 6 "Maintenance & repair".
WARNING
High temperature! Burning! Proceed with caution when brazing system
components. Do not touch the compressor until it has cooled down. Ensure
that other materials in the area of the compressor do not come into contact
with it.
CAUTION
Blockage! Compressor breakdown! Maintain a flow of oxygen-free nitrogen
through the system at very low-pressure during brazing. Nitrogen displaces
the air and prevents the formation of copper oxides in the system. If allowed
to form, the copper oxide material can later be swept through the system and
block screens such as those protecting capillary tubes, thermal expansion
valves, and accumulator oil return orifices.
Contamination or moisture! Bearing failure! Do not remove the connection
plugs until the compressor is set into the unit. This minimises any entry of
contaminants and moisture.
3.3.1 General brazing procedure
Copeland scroll compressors have copper-plated steel
suction and discharge stub tubes. These stub tubes are far
more robust and less prone to leaks than copper tubes. Due
to the different thermal properties of steel and copper,
brazing must be carried out in an appropriate manner.
Refer to Figure 6 and procedure below for the brazing of the
stub tube connections of a scroll compressor.
▪For systems with flammable A3 refrigerant, it is mandatory to flush oxygen-free nitrogen through
the piping during the brazing process.
▪The copper-coated steel tubes on scroll compressors can be brazed in approximately the same
manner as any copper tube.
▪Recommended brazing materials: any Silfos material is recommended, preferably with a
minimum of 5 % silver. However, 0 % silver is acceptable.
Figure 6: Brazing areas

8 AGL_HP_ST_ZHKCU_EN_Rev01
▪Be sure tube fitting inner diameter and tube outer diameter are clean prior to assembly.
▪Using a double-tipped torch, apply heat in area 1.
▪As the tube approaches brazing temperature, move the torch flame to area 2.
▪Heat area 2 until braze temperature is attained, moving the torch up and down and rotating around
the tube as necessary to heat the tube evenly. Add braze material to the joint while moving the
torch around the joint to flow braze material around the circumference.
▪After the braze material flows around the joint, move the 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.
NOTE: Since the discharge stub contains a check valve, care must be taken not to overheat
it to prevent brazing material from flowing into it.
3.3.2 Brazing procedure for ZH*KCU compressors in parallel applications
WARNING
Air/flammable refrigerant mixture! Creation of a potentially flammable
atmosphere! Fire hazard! Remove all refrigerant before opening the system.
When working on a refrigerant-filled system, make sure to follow the safety and
working instructions given in Chapter 6 "Maintenance & repair".
Only compressor models officially approved by Emerson in the qualified configuration may be used
for parallel applications. For ZH*KCU compressors in parallel applications with passive oil
management, additional precautions shall be taken before brazing the oil and gas equalization ports.
The sequence shall be as follows:
First, install the compressors on the base frame and tilt the assembly so that oil will not be lost when
opening the cap. The gas and oil equalization line assembly should be ready for brazing at this point.
For new compressors, release the protective gas charge: the rubber plug from the discharge port of
the compressor has to be removed first, then the rubber plug from the oil port.
Most probably the oil port will be coated with some oil. It is mandatory to clean out the oil before
brazing. If the inner surface is contaminated with oil the brazing material will not adhere to the surface
and the joint will fail, generating leakage. The oil should be carefully wiped out with industrial
absorption paper. Industrial solvents on a clean cloth can be used too but only with great care. Note
that emery cloth will not remove the oil.
It is possible that the oil cannot be completely cleaned out. In this case additional measures should
be taken. For instance, if a connection is coated with flux then the residual oil will be removed when
brazing thanks to the applied heat.
If an active oil level control is to be used, eg, OM* TraxOil from Alco Controls, please refer to the
product documentation when brazing the connection adaptor.
3.4 Pressure safety controls
Pressure protection devices to be used in ATEX Zone 2 locations must comply with the ATEX
Directive requirements. Non ATEX-certified pressure protection devices shall NOT be used in ATEX
Zone 2 locations.
ATEX-approved pressure protection devices are available from Alco Controls. Please refer to the
dedicated "Product Guide for R290".
3.4.1 High-pressure protection
Applicable regulations and standards, for example EN 378-2, shall be followed to apply appropriate
control and ensure that the pressure never exceeds the maximum limit.
High-pressure protection is required to stop the compressor operating outside the allowable pressure
limits. The high-pressure control must be installed correctly, which means that no service valve is
allowed between the compressor and the pressure protection.
The high-pressure cut-out setting shall be determined according to the applicable standard, the type
of system, the refrigerant and the maximum allowable pressure PS.

AGL_HP_ST_ZHKCU_EN_Rev01 9
3.4.2 Low-pressure protection
CAUTION
Operation outside the application envelope! Compressor breakdown! A
low-pressure protection shall be fitted in the suction line to stop the
compressor when it operates outside the envelope limits. Do not bridge or by-
pass the low-pressure limiter.
Applicable regulations and standards shall be followed to apply appropriate control and ensure that
the pressure is always above the required minimum limit.
Low-pressure protection is required to stop the compressor operating outside the allowable envelope
limits. The low-pressure control must be installed correctly into the suction line, which means that no
service valve is allowed between the compressor and the pressure protection.
The minimum cut-out setting shall be determined according to the refrigerant and the allowed
operation envelope –see Select software at www.climate.emerson.com/en-gb/tools-resources.
3.5 System protection for operation below atmospheric pressure
WARNING
Operation below atmospheric pressure! Fire hazard! During operation
below atmospheric pressure, a flammable mixture can form inside the system.
Ensure system tightness to prevent any ingress of air.
ZH*KCU compressors in R290 applications may be operated below atmospheric pressure only when
installed in hermetically-sealed systems. For non-hermetic systems, the pressure must always be
above atmospheric pressure. The operating pressure must be limited as defined by the operation
envelope –refer to the technical documentation.
When systems with ZH*KCU compressors operate below atmospheric pressure, special
requirements for safety and tightness apply and the following precautions must be observed:
▪Check all the critical points on the system and piping connections; tightness has to be ensured
also at very low pressure.
▪Minimum absolute working pressure: 0.5 bar.
▪The installation of mechanical high-pressure and low-pressure cut-outs is mandatory. For
systems provided with a service shut-off valve on the discharge side of the compressor, only a
mechanical pressure cut-out shall be used. Electronic pressure limiters, which could cause
delayed sensor response, are not allowed.
▪The high- and low-pressure cut-outs must be installed correctly on the discharge and suction
lines, which means that no service valve is allowed between the compressor and the pressure
protection (refer to EN 378 or ISO 5149).
▪A discharge temperature control is mandatory to stop the compressor when the maximum
discharge temperature is exceeded –see section 3.7 "Discharge gas temperature
protection".
▪Additional warning notices shall be affixed to any system equipped with shut-off valves. The
warnings must contain instructions to open the shut-off valves completely after each repair or
maintenance work. The compressors may only be energized when the safety measures (high-
and low-pressure cut-outs and discharge temperature cut-out) have been checked and verified
to be operational.
NOTE: All of the above points must be fulfilled. If only one of them is not complied with, the
compressors shall not be operated below atmospheric pressure.

10 AGL_HP_ST_ZHKCU_EN_Rev01
3.6 Crankcase heater
WARNING
Ignition source in a potentially flammable atmosphere! Fire hazard! The
crankcase heater, as specified by Emerson (see spare parts catalogue), is not
an ignition source during normal operation in A3 systems but could become
one if not installed properly according to installation instructions. Ensure
correct electrical and mechanical installation.
CAUTION
Overheating and burnout! Compressor damage! Never apply power to the
crankcase heater in free air, before the crankcase heater is installed on the
compressor or when it is not in complete contact with the compressor shell.
IMPORTANT
Oil dilution! Bearing malfunction! Turn the crankcase heater on 12 hours
before starting the compressor.
A crankcase heater is used to prevent refrigerant from migrating into the shell during standstill
periods. The installation of a crankcase heater is required when the system charge exceeds the
charge limits indicated in Table 7. This requirement is independent from system type and
configuration.
Compressor model
Refrigerant
charge limit
(kg)
Crankcase heater
Position
Height
(mm)
ZH04KCU & ZH06KCU
1.4
5 - 12
ZH08KCU
1.5
ZH09KCU to ZH13KCU
1.6
9.5 - 41
Table 7: Refrigerant charge limits & crankcase heater position
The initial start-up in the field is a very critical period for any compressor because all load-bearing
surfaces are new and require a short break-in period to carry high loads under adverse conditions.
The crankcase heater must be turned on a minimum of 12 hours prior to starting the
compressor. This will prevent oil dilution and bearing stress on initial start-up. The crankcase
heater must remain energized during compressor off cycles.
Crankcase heaters to be used in ATEX Zone 2 locations must comply with the ATEX Directive
requirements. Non ATEX-certified crankcase heaters shall NOT be used in ATEX Zone 2 locations.
NOTE: The crankcase heater presently available from Emerson is not ATEX-certified and can
only be used in non-flammable environments. In case this crankcase heater has to be ordered
from Emerson, please refer to the Copeland spare parts & accessories catalogue available at
www.climate.emerson.com/en-gb/tools-resources to select the correct model.
Caution: Crankcase heaters must be properly grounded!
For installation, the manufacturer/installer shall follow the recommendations mentioned below.
Assembly instructions
▪Choose the appropriate model according to compressor size and required wattage.
▪Check the compressor application guidelines for crankcase heater connection and operation.
▪Position the crankcase heater between the lower cover and the lower bearing weld projection
(Fig. 7).
▪Fit the heater horizontally around the crankcase, ensuring that it is in close contact with the
compressor housing along the entire length.
▪Avoid having the heating portion of the heater in contact with any weld projection (Fig. 8 & 9).
▪Avoid having the assembly heater inclined (Fig. 10).
▪Close the lock and tighten the screw, torque: 2 - 3 Nm.
▪The excess clamp bracket may be trimmed. Sharp edges must not come into contact with wires.

AGL_HP_ST_ZHKCU_EN_Rev01 11
▪The presence of the heater shall be made evident by the posting of caution signs or markings at
appropriate locations.
Figure 7 Figure 8 Figure 9 Figure 10
Electrical connection
▪Connect the crankcase heater according to the compressor application guidelines.
▪The crankcase heater must be connected only to its rated voltage.
▪The metal braid of the heater must be connected to a suitable earthing terminal.
▪Check the resistance according to the technical data.
▪Perform an insulation test before start-up.
▪Electrical security and safety measures are to be provided on site.
3.7 Discharge gas temperature protection
CAUTION
Inadequate lubrication! Scroll set damage! All ZH*KCU compressors must
be equipped with an external discharge gas temperature protection.
A good system control shall prevent the system from operating outside the published operating
envelope and acceptable superheat range, whatever the climatic conditions and the capacity
demand. However, under some extreme operating conditions (such as loss of charge or improper
control operation), the internal discharge gas temperature reached can cause compressor damage.
In order to guarantee positive compressor protection, discharge gas temperature protection is
required for any application with Copeland compressors.
The maximum discharge gas temperature is 135 °C for models ZH04KCU to ZH08KCU and 130 °C
for models ZH09KCU to ZH13KCU.
Discharge gas temperature protection is the "fall-back" for failure of the system control. It is essential
that proper control of both the evaporating and condensing pressures and the superheat is
maintained and has the ability to cope with all likely conditions and high loads. Reliance on protectors
will cause inadequate system performance and short cycling.
NOTE: The maximum discharge gas temperatures indicated in this chapter are valid for safe
operation within the approved application envelope. The discharge line thermostat has the
function of a compressor protection device; it is not designed to control the operating
envelope. For compressor envelope control, an additional control device or regulation must
be used.
3.7.1 Excessive discharge gas temperatures
A few of the possible consequences of excessive discharge gas temperatures are listed below:
▪Since the oil circulates in the system with the refrigerant, it is subjected to high discharge gas
temperatures. If the discharge gas temperature becomes too high, the so-called "cooking" effect
will occur (heating of oil under exclusion of air). Carbon deposits can form at points of high
temperature, for example on the valves, oil channels, oil filters, etc. The oil lubricity will be reduced
and a progressive wear process will occur which will prematurely damage the compressor.
▪The stability of the refrigerant can also be affected, particularly if traces of contaminant are
present.
The problems described above frequently occur simultaneously, particularly since the chemical
reaction speed approximately doubles with every 10 °C temperature rise. This directly leads to
chemical reactions of the oil with the refrigerant and the compounds extracted from sealants and
insulation material. As a consequence, contaminants of various types, among them acids, will form
inside the system.

12 AGL_HP_ST_ZHKCU_EN_Rev01
3.7.2 Discharge line thermostat
ZH*KCU compressors have no internal discharge gas temperature protection. Therefore, an external
discharge line thermostat must be installed.
Emerson can supply an ATEX discharge line thermostat which can be used with A3 refrigerants. It
can also be used in an ATEX zone 2 or non-ATEX environment. This thermostat is marked with a
special ATEX label –see Figure 11.
Figure 11: ATEX discharge line thermostat and ATEX label
Technical data of the discharge line thermostat
Compressor range
ZH*KCU
Voltage
120-240 V AC
Maximum amperage
5 A / 240 V
Operating temperatures
Open
134 °C (± 4 K)
Close
106 °C (± 8 K)
Wire insulation maximum temperature
150 °C
Clips for tube
Ø 12.7 mm (1/2")
Table 8: Discharge line thermostat –Technical data
To be ATEX-compliant, the cable ends of the thermostat must be connected with suitable cable
glands and electrical enclosure to achieve a minimum protection degree of IP54 according to
IEC 60079-15, clause 6.3. When connecting the cable ends, a creepage distance of minimum 4 mm
and a clearance distance of 2.5 mm between the conductive parts at different potentials must be
maintained. Maximal voltage and amps values for the thermostat and a protection against electrical
shock must be respected during the installation.
Additionally, the ATEX compliance requires a protection of the thermostat body against mechanical
damage, according to IEC 60079-0, clause 26.4.2, table 13. There is no need for an additional
housing around the thermostat body. Protection against mechanical damage to the thermostat can
be achieved with an overall cover or box placed around the compressor or refrigerant system.
To ensure proper functioning and to avoid false readings, the discharge line thermostat must be
installed and insulated according to the procedure and recommendations hereunder.
Assembly of the discharge line thermostat
▪Install the discharge line thermostat on the
discharge tube 120 mm from top cap.
▪Snap the retainer clip over the tube and onto
the thermostat.
▪The thermostat should be placed on the
discharge tube so that its body is in upward
position on a horizontal tube installation.
▪Ensure that the thermostat is not tilted.
▪The wire must not be in contact with the top
cap of the compressor or the discharge tube.
Care should be taken to route wires so that
they do not come into contact with sharp
objects.

AGL_HP_ST_ZHKCU_EN_Rev01 13
▪To avoid any impact on tripping temperature
by the ambient, the discharge line thermostat
must be insulated.
▪Wrap thermal insulation around the pipe left
and right of the thermostat and secure it with
plastic straps.
▪Wrap a second layer of insulation around the
first one and around the thermostat and
secure it with plastic straps.
3.8 Internal pressure relief valve
There is an internal pressure relief valve on ZH*KCU compressors. It opens at a differential pressure
of 28 bar ± 3 bar between high- and low-pressure sides. A high-pressure protection must be provided
by the system manufacturer/installer for each system and according to EN 378-2.
The IPR valve is a safety device, not an HP switch. It is not designed for repeated operation and
there is no guarantee that it will reset correctly if it does have repeated operation
3.9 Discharge check valve
ZH*KCU compressors contain an internal check valve on the discharge connection. The discharge
check valve prevents the high-pressure discharge gas from flowing rapidly back through the
compressor after shutdown.
NOTE: This check valve cannot be used with recycling pumpdown because it is not entirely
leak-proof.
3.10 Filter screens
CAUTION
Screen blocking! Compressor breakdown! Use filter screens with at least
0.6 mm openings.
The use of filter 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 thermal 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.
3.11 Mufflers
Gas flow through scroll compressors is continuous with relatively low pulsation. External mufflers
may not be required on Copeland scroll compressors. Due to system variability, individual tests
should be conducted by the system manufacturer to verify acceptable levels of sound and vibration.
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 at minimum 15 to maximum 45 cm 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 10 to 15 cm.
3.12 Sound shell
At this time, no sound shell attenuation for ZH*KCU compressors is available from Emerson. If a
sound shell is needed, particular attention shall be paid to its non-electrostatic properties –see
EN 60079-0, clause 7.4.
3.13 Insulation material
Insulation material is commonly used in a system to insulate the suction line, suction accumulator,
expansion valve bulb or discharge line thermostat. When choosing the insulation material for R290

14 AGL_HP_ST_ZHKCU_EN_Rev01
applications, particular attention shall be paid to its non-electrostatic properties, as it could be a
potential ignition source.
3.14 Reversing valves
Since Copeland scroll compressors have a very high volumetric efficiency, their displacements are
lower than those of comparable capacity reciprocating compressors. As a result, Emerson
recommends that the capacity rating on reversing valves be no more than 1.5 to 2 times the nominal
capacity of the compressor in order to ensure proper operation of the reversing valve under all
operating conditions.
Caution: Reversing valve sizing must be within the guidelines of the valve manufacturer. The
pressure drop required to ensure valve shifting must be measured throughout the operating range of
the unit and compared to the valve manufacturer's data. Low ambient heating conditions with low
flow rates and low pressure drop across the valve can result in a valve not shifting. This can lead to
a condition where the compressor appears not to be pumping, ie, balanced pressures. It can also
cause elevated compressor sound levels.
During a defrost cycle, when the reversing valve abruptly changes the refrigerant flow direction, the
suction and discharge pressures will go outside of the normal operating envelope. The sound that
the compressor makes during this transition period is normal, and the duration of the sound will
depend on the coil volume, outdoor ambient, and system charge level. The preferred method of
mitigating defrost sound is to shut down the compressor for 20 to 30 seconds when the reversing
valve changes position going into and coming out of the defrost cycle. This technique allows the
system pressures to reach equilibrium without the compressor running. The additional start-stop
cycles do not exceed the compressor design limits, but suction and discharge tubing design and
contactor life should be evaluated.
The reversing valve solenoid should be wired so that the valve does not reverse when the system is
shut off by the operating thermostat in the heating or cooling mode. If the valve is allowed to reverse
at system shut-off, suction and discharge pressures are reversed to the compressor. This results in
pressures equalizing through the compressor which can cause the compressor to slowly rotate
backwards until the pressures equalize. This condition does not affect compressor durability but can
cause unexpected sound after the compressor is turned off.
3.15 Sound and vibration
WARNING
Vibrations! Creation of a flammable atmosphere! Carefully check the
system for vibrations.
Vibrations during compressor operation can cause cracks which could lead to refrigerant leakage.
This situation must be avoided by the system manufacturer/installer. To this end, the pipework must
be carefully designed when connecting a scroll compressor to a system.
A scroll compressor makes both a rocking and twisting motion
and enough flexibility must be provided in the pipework to
allow starting, stopping and steady state running of the
compressor without transmitting excessive stress into any
line attached to the unit. In a split system, the most important
goal is to ensure minimal vibration in all directions to avoid
transmitting vibrations to the structure to which the lines are
fastened.
Under some conditions, the Copeland scroll has a normal
starting rotational motion that can transmit a transient noise
along the lines. This may be particularly pronounced in
compressors using a three-phase motor due to their
inherently higher starting torque. This phenomenon, like the
one described previously, can easily be avoided by using
standard line isolation techniques.
The sound level of a system is the result of design, quality and application. Scroll compressors sound
power levels generally increase with the compressor model capacity and the condition pressure ratio.
Figure 12: Example of suction tube design

AGL_HP_ST_ZHKCU_EN_Rev01 15
3.16 Compressor oil return, oil balancing, refrigerant floodback and oil dilution tests
CAUTION
Inadequate lubrication! Bearing and moving parts destruction! Ensure
adequate oil return from the system into the compressor at any time. No liquid
refrigerant return to the compressor. Liquid refrigerant dilutes the oil, could
wash the oil off the bearings and moving parts and could lead to overheating
and compressor failure.
The system piping must be carefully designed to ensure sufficient refrigerant gas velocity, so that oil
returns to the compressor at all times and conditions. Individual piping diameter calculation depends
on the refrigerant properties, pressure level, mass flow, and density.
Once a new system design is set and assembled, a functional test is required. The functional test
includes a qualification for the general system oil return, a refrigerant floodback test and an oil dilution
test. Systems with multiple compressors (two, three, or more) require additional oil balancing
qualification between the parallel compressors.
A sample compressor equipped with an external oil sight tube can be ordered from Emerson for lab
testing.
Records of the evaporating temperature and the bottom shell temperature shall be taken with a high
sampling rate during the entire oil return or oil balance testing and under all tested conditions. The
liquid level in the sight tube has to be observed and recorded too. Testing conditions shall include
defrost and varying loads. If the system is reversible, the tests should be conducted in both operation
modes.
System engineers should review the system design and operation to identify the critical conditions
and to check oil return, oil balancing, liquid floodback and oil dilution. For discussion of individual test
results and system behaviour, eg, with regard to oil dilution, please contact the Application
Engineering department. Typically, the following situations should be considered:
▪In single compressor systems: to check oil return, testing conditions shall be at minimum mass
flow and minimum density of suction gas in continuous and frequent start/stop cycling.
▪In multiple compressor systems: to check oil return and oil balancing in the tandem or trio,
testing conditions shall be at the corner points of the system application envelope in continuous
and frequent start/stop cycling.
▪In all systems: to test liquid floodback and oil dilution, all possible transient operation conditions
in the system should be checked, eg, compressor frequent start/stop, compressor start after long
off time with migration, defrost, switching between the operation modes in reversible systems,
load changes, fans or pumps cycling at low load and more. To evaluate the risk of liquid floodback
and oil dilution, please refer to the chart in Figure 13.
Figure 13: Oil dilution chart (tb = bottom shell temperature; te = evaporating temperature) and oil temperature
The bottom shell temperature together with the evaporating temperature gives an indication whether
liquid refrigerant is returning or diluted in the compressor oil sump. The compressor sump
temperature must remain in the (green) safe area, as shown in the chart in Figure 13. In case of