Emerson AE4-1395 Specifications

Application
Engineering
Application
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August 2012
3 to 15 Ton Copeland Scroll Digital™ Compressors for Air Conditioning
TABLE OF CONTENTS
Section
Page
Section
Safety
Safety Instructions.................................................. 2
Safety Icon Explanation......................................... 2
Instructions Pertaining to Risk of
Electrical Shock, Fire, or Injury to Persons............ 3
Safety Statements.................................................. 3
Digital Compressor Retrofit Applications
Reasons to Retrofit.................................................. 7
Retrofit Applications To Avoid................................... 8
Performance Modeling............................................. 8
System Modifications............................................... 8
Compressor Selection & Change-Out.................... 8
Refrigerant Flow Control........................................ 9
Evaporator Air Flow................................................ 9
Condenser Air Flow................................................ 9
Modulation Control................................................. 9
Introduction
Nomenclature ........................................................ 4
Digital Compressor Operation ............................... 4
How It Works ........................................................ 4
Assembly Line Procedures
3 To 7.5 Ton Modulation Valve Brazing Procedure....9
Pressure Testing.......................................................9
Application Considerations
Operating Envelope............................................... 4
Solenoid Valve and Coil......................................... 5
Pressure Fluctuations............................................ 5
Piping..................................................................... 5
Start Up and Shut Down........................................ 5
Compressor Cycling............................................... 5
Sound Characteristics............................................ 5
Internal Pressure Relief (IPR) Valve....................... 5
High Pressure Control............................................ 5
Low Pressure Control............................................. 5
Scroll Temperature Protection................................ 6
Crankcase Heaters................................................ 6
Oil Type and Oil Removal ...................................... 6
Power Factor.......................................................... 6
Tandem Applications.............................................. 6
Modulation Control................................................. 7
Service Procedures
Modulation Troubleshooting....................................10
3 to 7.5 Ton Modulation Valve Replacement
Procedure................................................................10
8 To 15 Ton Modulation Valve Replacement
Procedure................................................................10
Scroll Compressor Functional Check...................... 11
Figures & Tables
Digital Cycle Example.............................................12
3 to 7.5 Ton Digital Scroll Cross Sectional View......12
8 to 15 Ton Digital Scroll Cross Sectional View.......13
3-7.5 Ton Operating Envelope.................................14
8-15 Ton Operating Envelope..................................14
Compressor Capacity Graph...................................15
Discharge Thermistors............................................15
3 to 7.5 Ton Modulation Valve Piping......................16
3 To 7.5 Ton Tandem...............................................16
Modulation Troubleshooting....................................17
Copeland Scroll Digital Family Features.................18
Refrigerant Charge Limits.......................................18
Torque Values..........................................................18
Compressor Accessories........................................19
Application Tests
Oil Level Verification............................................... 7 Excessive Liquid Floodback Tests.......................... 7
Operating Envelope Tests...................................... 7
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Safety Instructions
Safety Instructions
™ compressors are manufactured according to the latest U.S. and European Safety
Copeland Scroll™
compressors are manufactured according to the latest U.S. and European Safety Standards.
Standards.
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Safety Icon Explanation
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result
in death or serious injury.
WARNING
WARNING indicates a hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION
CAUTION, used with the safety alert symbol, indicates a hazardous
situation which, if not avoided, could result in minor or moderate injury.
NOTICE
CAUTION
© 2012 Emerson Climate Technologies, Inc.
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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.
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Instructions Pertaining to Risk of Electrical Shock, Fire, or Injury to Persons
WARNING
ELECTRICAL SHOCK HAZARD
• Failure to follow these warnings could result in serious personal injury.
• 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.
•
WARNING
PRESSURIZED SYSTEM HAZARD
• Failure to follow these warnings could result in serious personal injury.
• 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.
WARNING
BURN HAZARD
• Failure to follow these warnings could result in serious personal injury or
property damage.
• 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.
CAUTION
COMPRESSOR HANDLING
• Failure to follow these warnings could result in personal injury or
property damage.
• Use the appropriate lifting devices to move compressors.
• Personal safety equipment must be used.
Safety Statements
• Refrigerant compressors must be employed only for their intended use.
•
install, commission and maintain this equipment.
•
• All valid standards and codes for installing, servicing, and maintaining electrical and
refrigeration equipment must be observed.
© 2012 Emerson Climate Technologies, Inc.
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Introduction
The 3 to 15 ton Copeland Scroll Digital compressors
described in this bulletin include the follow compressor
model numbers:
R-22 & R-407C
ZPD34 to ZPD54K5
ZRD36 to ZRD81KC
ZPD61 to ZPD91KC
ZRD94 to ZRD125KC
ZPD103 to ZPD182KC
ZPD and ZRD digital scroll compressors are variable
capacity compressors that can modulate down to 10%
of full load. Digital scrolls are suitable for a variety of
applications where a variable capacity compressor is
useful, such as VAV applications, dedicated outside
air units, units that typically used hot gas bypass for
capacity control, and applications that require accurate
control of temperature and humidity. Other applications
include multiple compressor systems where modulation
is required over the entire operating range of the system
and in applications where compressor starting and
stopping is unacceptable. Typical digital scroll model
numbers are ZRD94KCE-TF5 and ZPD182KCE-TWD.
This bulletin describes the operating and application
differences with respect to the equivalent fixed
capacity Copeland Scroll™ compressors. The following
Application Engineering bulletins should be consulted
for non-modulating scroll application guidelines:
AE4-1331
AE4-1365
AE4-1303
AE4-1312
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AE4-1395
An example for the 15 second controller cycle: In any
15 second cycle, if the loaded time is 10 seconds and
the unloaded time is 5 seconds, the average capacity
is 66% or if the loaded time is 5 seconds and the
unloaded time is 10 seconds the capacity during that
15 second period is 33%. See Figure 1 for a graphical
representation of the digital cycle, and Figure 6 for
a graph showing solenoid on-time vs. compressor
capacity.
How it Works
The digital scroll compressor unloads by taking
advantage of the Copeland Scroll compressor's
axial compliance. All Copeland Scroll compressors
are designed so that the compression elements can
separate axially a few thousands of an inch. The 3
through 7.5 ton compressors described in this bulletin
use a lift piston mechanism to separate the scrolls during
the unloaded state. When the solenoid is energized the
volume on top of the piston is vented to the low side
allowing the piston and fixed scroll assembly to move
axial away from the orbiting scroll. When the solenoid is
de-energized the piston is forced down and the scrolls
are loaded axially.
1.5 to 5 Ton R-410A
5 to 7.5 Ton R-410A
8 to 15 Ton R-22, R-407C & R-410A
1.5 to 7 Ton R-22 & R-407C
Nomenclature
The model number of the Copeland Scroll Digital
compressors includes the approximate nominal
60 Hz capacity at the AHRI high temperature full
load air conditioning rating point. An example is the
ZPD120KCE-TFD, which has approximately 120,000
Btu/hr cooling capacity at the air conditioning rating
point when operated on 60 Hz. Note that the same
compressor will have approximately 5/6 of this capacity
or 100,000 Btu/hr when operated on 50 Hz power.
Please refer to the Online Product Information at
www.EmersonClimate.com for more information on
performance at part load.
The 8 ton and larger digital scroll compressors employ
a solenoid valve that is mounted on the side of the
compressor that vents the intermediate cavity to the
low side of the compressor during the unloaded state.
During the loaded state the solenoid valve is deenergized and the intermediate cavity is pressurized
to load the floating seal and scrolls axially.
Please refer to Figures 2 and 3 for cross sectional
pictures of the two digital modulation mechanisms.
Digital Compressor Operation
APPLICATION CONSIDERATIONS
The digital scroll is capable of seamlessly modulating
its capacity from 10% to 100%. A normally closed
(de-energized) solenoid valve is a key component for
achieving modulation. When the solenoid valve is in its
normally closed position, the compressor operates at
© 2012 Emerson Climate Technologies, Inc.
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full capacity, or loaded state. When the solenoid valve
is energized, the two scroll elements move apart axially,
or into the unloaded state. During the unloaded state,
the compressor motor continues running, but since
the scrolls are separated, there is no compression.
During the loaded state, the compressor delivers 100%
capacity and during the unloaded state, the compressor
delivers 0% capacity. A cycle consists of one loaded
state and one unloaded state. By varying the time of
the loaded state and the unloaded state, an average
capacity is obtained. The lowest achievable capacity is
10% which equates to 1.5 seconds of pumping during
one 15 second cycle.
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R-410A
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Operating Envelope
The operating envelope of the digital scroll compressors
for all loading conditions is shown in Figures 4 and 5.
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Compressor operation during the loaded state should
always be inside of the envelope. The envelopes
represent allowable operation of the compressor with
20F° suction superheat at rated voltage. If the specified
modulation ranges are exceeded, overheating of the
compressor and tripping of the overload can occur
because of inadequate motor cooling.
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Compressor Cycling
Because of the digital scroll's seamless capacity
modulation from 10% to 100%, capacity short cycling
should not be a problem for single compressors.
However, if the digital compressor is in tandem with a
non modulated scroll, short cycling of the non modulated
compressor may be a problem if the system control is
not designed and set correctly. The Emerson digital
controllers have a built in two minute anti-short cycle
timer to prevent short cycling.
Solenoid Valve and Coil
The external solenoid valve and coil specified by
Emerson must be used since this is a critical component
for the proper functioning of this compressor. The
solenoid valve and coil are designed for approximately
32 million cycles. Do not attempt to substitute
replacement coils or valves; use only the replacement
parts specified in Table 4. Refer to the Service
Procedures section for information on changing the
modulation valves.
Sound Characteristics
The sound spectrum of the loaded state and the
unloaded state are different. Special consideration
should be given to the transition sound between the
loaded and unloaded states. If the transition sound
is unacceptable, a heavy sound blanket should
be applied to the compressor. Fabricating Services
(www.fabsrv.com) is a one source for scroll compressor
sound blankets.
Pressure Fluctuations
During scroll modulation the suction and the discharge
pressure will fluctuate. This fluctuation should be
observed during unit testing. The installation and setting
of pressure controls should take this into account.
During the unloaded state, the discharge pressure will
decrease and the suction pressure will increase. This
normal pressure fluctuation has had no observable
effect on the reliability of system components, however,
component manufacturers should be consulted to
ensure the proper application of their products.
The Emerson controllers unload the compressor a
fraction of a second before shut down allowing the scroll
set to unload, ensuring a relatively quiet shutdown.
Internal Pressure Relief (IPR) Valve
WARNING
A high pressure control must be used in all
ZRD94-125KC and ZPD103-182KC applications
because these compressors do not have internal
pressure relief (IPR) valves.
Piping
Unlike a variable speed compressor whose mass flow
and gas velocity changes with its speed, the digital
scroll’s pumping capacity is equal to its 100% capacity
while it is pumping. For this reason the gas velocity
remains high even during periods when the capacity
demand is low. Because the mass flow and gas velocity
remain high, piping may be designed as if it were
designed for a non capacity controlled compressor. For
vertical piping a trap every 20 feet should be sufficient
to ensure proper oil return. This recommendation is
based upon a minimum 1500 fpm velocity or higher.
When the digital scroll compressor is part of a tandem,
a double riser should be considered to assure that the
velocity remains above 1500 fpm when only the digital
scroll is running.
High Pressure Control
As mentioned above, not all digital scrolls have IPR
valves, therefore high pressure controls are required
in some applications. The recommended maximum cut
out setting is 425 psig (30 bar) for R-407C & R-22 and
650 psig (45 bar) for R-410A. The high pressure control
should have a manual reset feature for the highest
level of system protection. This pressure control must
act independently of the digital compressor controller.
Low Pressure Control
Air-conditioning units can be protected against high
discharge temperatures through a low pressure control in
the suction line. Testing has shown that a cut out setting
of not lower than 55 psig (3.8 bar) for R-410A and 25
psig (1.7 bar) for R-407C & R-22 will adequately protect
the compressor against overheating from loss of charge,
blower failure in a TXV system, etc. A higher level of
protection is achieved if the low pressure control is set to
cut out at 95 psig (6.7 bar) for R-410A and 55 psig (3.8
Start Up and Shut Down
To improve the starting characteristics of the digital
scroll compressor, the the Emerson controllers delay
loading the compressor for 0.1 seconds. Likewise, to
eliminate the reverse rotation sound at shut down the
compressor is unloaded 0.5 seconds before shut down.
© 2012 Emerson Climate Technologies, Inc.
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bar) for R-407C & R-22 to prevent evaporator coil icing.
The cut in setting can be as high as 180 psig (12.5 bar)
for R-410A and 105 psig (7.2 bar) for R-407C & R-22 to
prevent rapid recycling in case of refrigerant loss.
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RL32-3MAF) should be used. Copeland Ultra 22 CC,
Hatcol EAL 22CC, and Mobil EAL Arctic 22 CC are
acceptable alternatives.
If additional oil is needed in the field for mineral oil
applications, Sonneborn Suniso 3GS or Chevron
Texaco Capella WF32 should be used.
For heat pumps, a cut out setting no lower than 20 psig
(1.4 bar) is recommended for R-410A and 10 psig (0.7
bar) for R-407C & R-22.
CAUTION
Scroll Temperature Protection
POE must be handled carefully and the proper
protective equipment (gloves, eye protection, etc.)
must be used when handling POE lubricant. POE
must not come into contact with any surface or
material that might be harmed by POE, including
without limitation, certain polymers (e.g. PVC/CPVC
and polycarbonate).
Most digital scrolls do not have internal discharge
gas temperature protection. In order for the Emerson
controllers to operate properly an NTC sensor must be
attached to the compressor discharge line as close as
possible to the compressor discharge fitting. For best
response the sensor should be insulated. See Table 1
of AE8-1328 for thermistor temperature vs. resistance
values. Refer to Table 4 for part numbers of discharge
line thermistors. Figure 7 illustrates the two different
types of discharge thermistors.
Power Factor
During the loaded state the digital scroll compressor
operates at full capacity and the power factor is the
same as a standard scroll. However, when the scrolls are
unloaded, the power factor is much lower. If power factor
is an important consideration, the correcting capacitors
should be calculated using the full capacity data to avoid
problems associated with over correction. See AE9-1249
for more information on power factor correction.
The ZRD61 through ZRD81KC compressors have a
discharge thermistor that is inside of a well in the top
cap of the compressor. If this thermistor ever needs to
be replaced, it should be replaced with either 985-019900 or 085-0204-00 as listed in Table 4.
Crankcase Heaters
Tandem Applications
A crankcase heater is required if the system charge
exceeds the system charge limits listed in Table 2.
For more information regarding regarding heater part
numbers and installation location please refer to the
equivalent non-digital scroll Application Engineering
bulletin listed on Page 4.
Tandem compressors follow the same application
guidelines as single compressors outlined in this bulletin.
The refrigerant charge limit for tandem compressors is
shown in Table 2. A tandem circuit with a charge over
this limit must have crankcase heaters applied to both
compressors.
Oil Type and Oil Removal
Tandem compressor assemblies are available for
purchase from Emerson. In lieu of purchasing the
assembled tandem, the OEM has the option to
purchase the tandem-ready compressors to assemble
the compressors into a tandem configuration in their
manufacturing plant. Drawings of the tandem manifolds
are available by contacting your application engineer.
Figure 9 illustrates a typical tandem compressor
assembly using 3 through 7.5 ton scroll compressors.
Note that only one compressor in the tandem assembly
is a digital scroll compressor. Customers that choose
to design and build their own manifolds for tandem
and trio compressor assemblies are ultimately
responsible for the reliability of those manifold sets.
Mineral oil is used in the ZRD*KC compressors for
R-22 applications. Polyolester (POE) oil is used in
the ZRD*KCE and ZPD*KCE compressors for R-22
& R-407C and R-410A applications respectively. See
the compressor nameplate for the original oil charge. A
complete recharge should be approximately four fluid
ounces (118 ml) less than the nameplate.
It is an approved practice to use ZRD*KCE compressors
with POE to replace ZRD*KC compressors with mineral
oil in R-22 service applications. R-22 has been approved
for use with both mineral and POE and some mixing of
these oil in the system is acceptable.
If additional oil is needed in the field for POE
applications, Copeland™ Ultra 32-3MAF, Lubrizol
Emkarate RL32-3MAF, Parker Emkarate RL32-3MAF/
Virginia LE32-3MAF, or Nu Calgon 4314-66 (Emkarate
© 2012 Emerson Climate Technologies, Inc.
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For more information on tandems, please refer to the
non-modulating compressor Application Engineering
bulletins listed on Page 4.
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Modulation Control
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If the system contains more than 20 pounds (9 kg) of
refrigerant, it is our recommendation to add one fluid
ounce of additional oil for every 5 pounds (15 ml/kg)
of refrigerant over this amount. This is a starting point
and oil should be added as determined through system
testing or as required by the end use application in the
field.
Two different controls are available from Emerson to
provide digital scroll modulation control, the Copeland
Scroll™ Digital Compressor Controller and the Emerson
Commercial Comfort Controller.
The Copeland Scroll™ Digital Compressor Controller is
an open loop controller that provides control, protection,
and diagnostics for the digital scroll and is suited for
OEM applications. The system controller supplied by the
OEM calculates the required compressor capacity and
communicates that capacity to the digital scroll controller
via a 1-5 VDC analog signal. For more information on
the Copeland Scroll Digital Compressor Controller please
refer to AE8-1328.
The compressor oil level should be checked with
the compressor "off" to avoid the sump turbulence
when the compressor is running. Manifolded
compressors should have their oil levels checked
after 20 to 30 seconds of off time, to allow oil
balancing between the manifolded compressors.
Excessive Liquid Flood Back Tests
The Emerson Commercial Comfort Controller is a closed
loop controller that provides modulation control based
on space temperature and is suited for both OEM and
retrofit applications. This controller is typically located in
the conditioned space and controls the modulation cycle
of the compressor without the need for an additional
system controller. For more information on the Emerson
Commercial Comfort Controller, please refer to AE8-1393.
It is expected that the design will not flood during
operation at all of the varying loaded and modulation
conditions. This places demanding requirements
on the flow control device to control refrigerant flow
and superheat all the way down to 10% of full load.
Throughout the operating range of the unit, the
suction superheat must remain positive. If the
flow control device is unable to maintain superheat,
an electronic expansion valve, accumulator, or other
means must be taken to maintain at least 20°F of
compressor sump superheat.
NOTICE
For OEMs that choose their own controls
package, the controls must include the protection
features incorporated into the Copeland Scroll™
Digital Compressor Controller. Please consult
with Application Engineering for a list of these
requirements.
Operating Envelope Test
The operating envelopes and recommended modulation
ranges are shown in Figures 4 and 5. System testing must
be performed if operation outside of these recommended
ranges is desired. System testing should consist of unit/
system operation at abnormal operating conditions to
verify that suction superheat and compressor discharge
temperatures stay in a range that is healthy for the
compressor and tripping of the compressor overload is
avoided. Please consult with application engineering for
recommended tests and analysis of test data.
APPLICATION TESTS
Oil Level Verification
If the system configuration is more complex than a
single circuit packaged system with one compressor,
evaporator, and condenser, an oil return test is highly
recommended during system development testing. For
this test a sample compressor with a sight-tube should
be used to observe the oil level over the entire operating
range of the system at the expected compressor
modulation rates, to ensure an adequate oil level in
the compressor at all times. The oil level should not
go below the weld points of the lower bearing bracket
for the 3 through 7.5 ton compressors. For the 8 ton
and larger digital scrolls the minimum oil level is 1.5"
(40 mm) below the center of the standard oil sightglass on the compressor. If the oil level falls below the
prescribed level for more than a few minutes either more
oil is required in the system or an oil recovery cycle is
needed. For more information on what an oil recovery
cycle is, please consult with Application Engineering.
© 2012 Emerson Climate Technologies, Inc.
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DIGITAL COMPRESSOR RETROFIT APPLICATIONS
Reasons To Retrofit
There are a number of reasons why retrofitting a nonmodulating system to one that modulates will benefit
the building owner and its occupants. Some of these
reasons include:
1. Reduced indoor temperature and humidity swings
2. Reduced power consumption and operating costs
3. Reduced cyclic losses
4. Qualification for special utility rebates
Applications that have excess cooling capacity and are
single zone, constant or variable air-flow are certainly
in the scope of retrofit opportunities. Units that employ
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hot-gas-bypass for capacity control are also ideal units
for a digital scroll retrofit.
have specific instructions developed that offer
step by step guidance.
Retrofit Applications To Avoid
Before beginning the retrofit, the system should be
operable and system operating conditions should be
logged for future reference. The compressor suction
& discharge pressures, suction superheat, subcooling,
volts, amps, evaporator air flow and leaving temperature,
and system charge should all be measured and recorded
prior to any system modifications.
NOTICE
Always check with the original equipment
manufacturer, before modifying the equipment,
to understand their warranty policies regarding
equipment modifications.
The success of the retrofit will depend on the amount
of planning and evaluation done before the retrofit.
Applications such as clean rooms for manufacturing
sensitive components, laboratories, hospital operating
and recovery rooms, and equipment rooms that require
constant cooling are all applications that would benefit
from a modulating digital scroll. Many of these are
critical cooling applications and require equipment that
is designed specifically for these applications. Don’t
attempt to retrofit a non-modulating HVAC unit, in a
critical application, to one with a digital scroll in an attempt
to make the unit perform well beyond its intended use.
Compressor Selection & Change-Out
The replacement digital scroll compressor should be
compared to the non-modulating compressor in at least
these three areas:
1. Performance – the full load capacity of the digital
scroll should be approximately equal to the capacity
of the compressor being replaced. In some cases
in might make sense to “right size” the compressor
capacity for the load if the compressor is grossly
oversized.
2. Electrical – the digital scroll compressor RLA and
LRA should be compared to the compressor being
replaced. Contactor, wire, breaker/fuse, and run
capacitor sizes should be evaluated.
Applications that have complex refrigeration circuits
(modulating reheat, heat recovery for water heating,
etc.) should not be considered for a digital scroll retrofit.
3. Mechanical – in most cases the compressor
mounting will be identical for the non-modulating
and the digital scroll. There could be minor
difference in the suction and discharge tubing
locations, as well as the height of the compressor.
Performance Modeling
NOTICE
Emerson Climate Technologies, Inc. is not
responsible or liable for incorrect energy use
predictions.
The following steps should be followed to remove the
non-modulating compressor from the system.
Successful digital scroll retrofit projects, and resultant
energy savings, have been documented by several
industry energy groups. Predicting the energy usage
and calculating a return on investment before the
project is undertaken is not trivial and is best done by
experienced companies that use advanced software
programs to predict energy use. Before large retrofit
projects are considered, as much front-end analysis
as possible should be done to better predict how much
energy might be saved. Tabular performance data and
the ten coefficients for the AHRI polynomial equation for
performance at 50% and 100% load are available for
modeling purposes in the Online Product Information
(OPI) section at www.EmersonClimate.com.
1. Using an EPA approved refrigerant recovery
machine, recover the system refrigerant charge
from the low and high sides of the system.
2. Disconnect and lockout the power supply.
Confirm that all voltage sources have been
disconnected by using a voltmeter. Disconnect the
conduits and wiring to the compressor and move
them out of the way as much as possible.
3. By using manifold gauges, verify that the system
refrigerant charge is completely recovered from
the system. Suction and discharge pressures must
be 0 psig.
4. Using a tubing cutter, cut the suction and discharge
lines close to the compressor.
System Modifications
NOTICE
5. Remove the compressor mounting bolts.
6. Plug the compressor suction and discharge
connections to prevent the spillage of oil from the
compressor when removing it from the system.
Always check with the OEM of the equipment
being considered for the digital scroll retrofit,
before the retrofit is undertaken. The OEM may
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7. Using the appropriate lifting devices, carefully
remove the compressor from the system.
remove latent heat. In desert and arid climates, because
of low or no latent loads, air flow is less critical.
The following steps should be followed to install the digital
compressor into the system.
The controls required for variable air flow are not provided
by Emerson so the contractor may need to consult with
controls experts in this field.
1. Before removing the rubber plugs, install the
compressor in the unit on the mounting grommets
using the appropriate lifting devices.
Condenser Air Flow
Modulating the condenser air flow is not critical to the
success of the application. For the highest level of energy
savings, condenser air flow will be reduced based on the
compressor modulation rate, condensing temperature,
ambient temperature, etc.
2. Install the compressor mounting bolts.
3. Connect the suction and discharge lines using
standard brazing practices.
4. If the compressor has an external modulation valve
and tubing (3 to 7.5 ton only) refer to Figure 8 for the
correct valve orientation and position. Wrap a wet
rag around the valve and complete the assembly
by brazing the valve and tubing into place.
Modulation Control
The preferred modulation control for retrofit applications
is the Commercial Comfort Controller. This controller is a
closed loop controller that is installed in the conditioned
space. The controller measures the space temperature
and through an algorithm in the controller, controls the
modulation of the digital scroll. The controller can be
positioned up to 300 feet from the compressor/unit, is
configurable for roof top unit or heat pump, and is wired
like a commercial room thermostat. For more information
on the Commercial Comfort Controller please refer to
AE8-1393.
ASSEMBLY LINE PROCEDURES
5. Check for leaks using nitrogen with a properly sized
regulating and relief valve.
6. Connect conduits and wiring to the compressor.
Inspect and/or replace the contactor. If the
compressor is 1-phase, install the correct run
capacitor.
NOTICE
The above procedures for changing the
compressor are not comprehensive and additional
steps/procedures may be necessary.
3 To 7.5 Ton Modulation Valve Brazing Procedure
The external modulation valve is purchased and shipped
separately from the 3 to 7.5 ton digital scroll. Therefore,
assembly is required in the OEM manufacturing plant.
Figure 8 illustrates the correct position and orientation
of the modulation valve. Please note the direction of the
arrow on the valve, it must point to suction.
Refrigerant Flow Control
In the system with a digital compressor, the refrigerant
flow control valve is required to control flow across a wide
range of flow rates and varying pressure differentials.
Most balanced port thermostatic expansion valves can
control flow down to about 40% of their rated capacity.
Excessive hunting and loss of superheat control can
result when asking a thermostatic expansion valve to
operate outside of its design range. For this reason,
the expansion device needs to be evaluated to ensure
reliable operation over the expected operating range.
Limiting the minimum compressor modulation rate to
a value that the expansion valve can tolerate should
be considered. Electronic expansion valves should be
considered if modulation over the entire range of the
compressor’s modulation range is anticipated.
When brazing the modulation valve into the system,
the valve must be wrapped with a wet rag to help keep
the valve cool. The torch flame must be directed away
from the valve and the brazing operation should be
done quickly so the valve isn't overheated. The brazing
operation should be performed with a nitrogen purge to
prevent the build-up of copper oxide. The solenoid coil
should be installed after the brazing operation, so the
leads are kept away from the brazing operation and the
wet rag is able to fully contact the valve body.
Pressure Testing
Evaporator Air Flow
For the highest level of energy savings, comfort, and
efficiency the variable capacity system should be capable
of varying the air flow. Variable frequency drives and
tapped blowers are two means of reducing air flow. Reducing air flow in humid or maritime climates is
important to maintain coil temperatures low enough to
© 2012 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
The pressure used on the OEM assembly line to meet
the UL burst pressure requirement cannot be higher
than 400 psig (27.6 bar) for R-407C & R-22 and 475
psig (32.8 bar) for R-410A. Higher pressure may result
in permanent deformation of the compressor shell and
possibly cause misalignment or bottom cover distortion.
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systems, carefully braze the new valve into the
system, directing the torch flame away from the
valve body.
Modulation Troubleshooting
The modulation valve and solenoid coil are engineered
for specific use with the digital scroll. Don’t attempt to
substitute replacement solenoid coils that are not of
the correct part number. The 3 to 7.5 ton modulation
valves must be installed in the correct orientation and
with the arrow on the valve pointing to suction. Installing
a modulation valve in a horizontal position, or with the
suction and discharge connections reversed, can result
in sporadic operation of the modulation valve. See
Figure 8 for an illustration of the correct valve location
and orientation.
10. Check for leaks using nitrogen with a properly sized
regulating and relief valve.
11. Install the solenoid coil and torque the retaining
screw to 25 in-lbs.
12. Evacuate the compressor/system and put the
system back into operation.
8 To 15 Ton Modulation Valve Replacement
Procedure
The 8 through 15 ton digital scroll compressors have
a modulation valve that is replaceable in the event the
valve stops functioning. The modulation valve threads
into a receptacle that is inside the small terminal box on
the compressor. To replace the modulation valve, follow
these recommended steps:
Figure 10 is a troubleshooting flow chart to help with
simple modulation problems. For more information on
troubleshooting the Copeland™ Digital Compressor
Controller please refer to AE8-1328. For more
information on troubleshooting the Emerson Commercial
Comfort Controller please refer to AE8-1393.
1. Disconnect and lockout the power to the unit.
3 to 7.5 Ton Modulation Valve Replacement
Procedure
2. Recover the refrigerant charge from the compressor/
system.
The 3 through 7.5 ton digital scroll compressors employ
a modulation valve that is mounted external to the
compressor in the modulation tubing. To replace the
modulation valve, follow these recommended steps:
3. Remove the cover from the small terminal box and
remove the screw holding the coil to the valve using
a Phillips screwdriver or appropriate size nut driver.
4. Remove the coil from the valve and clean the area
around the valve body to prevent debris and dirt
from entering the system when changing the valve.
1. Disconnect and lockout the power to the unit.
2. Recover the refrigerant charge from the compressor/
system.
5. Using manifold gauges, double check to make
sure the refrigerant charge is completely
recovered from the compressor before
proceeding.
3. Remove the screw holding the coil to the valve
using a Phillips screwdriver or appropriate size nut
driver.
6. Using a 7/8” deep well socket and ratchet, turn the
valve counterclockwise to remove the valve.
4. Remove the coil from the valve.
5. Using manifold gauges, double check to make
sure the refrigerant charge is completely
recovered from the compressor before
proceeding.
7. Visually inspect the valve receptacle on the
compressor for damage or debris. Ensure that the
black o-ring and white Teflon gasket are removed
with the valve and do not remain on the valve
receptacle.
6. Using tubing cutters, cut the modulation tubing
close to the valve body leaving the valve tubing
stubs in the suction “T” connection and the swaged
tubing from the compressor top cap.
8. The replacement valve should have a new,
black o-ring and white, Teflon gasket as shown:
7. Carefully unbraze and remove the tubing stubs from
the suction “T” and top cap tubing swage. Carefully
unbrazing and removing these stubs will allow the
tubing/suction “T” fitting to be reused.
8. After these fittings have cooled, clean the fittings
and prepare to braze the new valve in place. Wrap
a wet rag around the valve body to keep from
overheating the valve.
9. Using standard brazing practices for refrigeration
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9. Use care when handling the replacement
valve – don’t drop the valve or impact the
solenoid stem. If the valve is dropped or
damaged, discard it and obtain a new valve
for replacement.
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5. If suction pressure does not drop and discharge
pressure does not rise to normal levels, reverse
any two of the compressor power leads (this
procedure is for 3-phase compressors only) and
reapply power to make sure compressor was not
wired to run in reverse direction. If pressures still
do not 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.
10. Lightly oil the gaskets with refrigeration oil and
hand tighten the new modulation valve into the
valve receptacle on the compressor.
11. Using a 7/8” deep well socket and a torque wrench,
torque the modulation valve to 230 in-lbs.
12. Check for leaks using nitrogen with a properly
sized regulating and relief valve.
The solenoid coil should only be energized
when it is installed on the solenoid valve.
Energizing the coil when it is not installed on
the valve will result in a failed coil.
13. Install the solenoid coil and torque the retaining
screw to 25 in-lbs.
14. Install the terminal box cover, evacuate the
compressor/system, and put the system back into
operation.
Note: It is also possible that the unloader valve is
not closed. With the compressor off, cycle power
to the unloader solenoid and listen for clicking. If
no sound is heard the valve is very likely stuck.
NOTICE
6. 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 system. If the measured average current
deviates more than ±15% from published values,
a faulty compressor may be indicated. A current
imbalance exceeding 15% of the average on the
three phases should be investigated further. A
more comprehensive trouble-shooting sequence
for compressors and systems can be found in
Section H of the Emerson Electrical Handbook,
Form No. 6400.
The above procedures for changing the
modulation valve are comprehensive. Depending
on the equipment being serviced, additional steps
may be required. Refer to OEM instructions for
more information.
Copeland Scroll Compressor Functional Check
A functional compressor test with the suction service
valve closed to check how low the compressor will pull
suction pressure is not a good indication of how well a
compressor is performing. Such a test may damage a
scroll compressor. The following diagnostic procedure
should be used to evaluate whether a Copeland Scroll
compressor is working properly.
7. Before replacing or returning a compressor: Be
certain that the compressor is actually inoperable.
As a minimum, recheck a compressor returned
from the field in the shop or depot for Hipot,
winding resistance, and ability to start before
returning. More than one-third of compressors
returned to Emerson for warranty analysis
are determined to have nothing found wrong.
They were misdiagnosed in the field as being
inoperable. Replacing working compressors
unnecessarily costs everyone.
1. Proper voltage to the unit should be verified.
2. The normal checks of motor winding continuity
and short to ground should be made to determine
if the inherent overload motor protector has
opened or if an internal motor short or ground fault
has developed. If the protector has opened, the
compressor must be allowed to cool sufficiently to
allow it to reset.
3. Proper indoor and outdoor blower/fan operation
should be verified.
4. Remove power from the unloader solenoid to
load the compressor 100% . 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.
© 2012 Emerson Climate Technologies, Inc.
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80% Loaded
PUMPING
PUMPING
7.5 s
7.5 s
12s
NOT PUMPING
3s
NOT PUMPING
15 seconds
One Cycle of 15 seconds
Figure 1
Digital Cycle Example
Figure 2
3 to 7.5 Ton Digital Scroll Cross Sectional View
Note: Modulation tubing is show for reference only.
Refer to Figure 8 for the correct modulation tubing configuration.
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90 Frame Digital Scroll
Floating Seal Cavity
Seal Cavity Vent
Removable External
Solenoid and Coil
Figure 3
8 to 15 Ton Digital Scroll Cross Sectional View
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R-22, R-407C, R-410A Operating Envelope
160
AE4-1395
ZPD34-54K5
ZPD61-91KC
ZRD36-81KC
150
Condensing Temperature (°F)
140
130
Recommended
Capacity
Range
10 -100%
120
Recommended
Capacity
Range
50 -100%
110
100
Recommended
Capacity
Range
75 -100%
90
80
70
-20
-10
0
10
20
30
Evaporating Temperature (°F)
40
50
60
Figure 4
R-22, R-407C, R-410A Operating Envelope
160
ZPD103-182KC
ZRD94-125KC
150
140
Condensing Temperature (°F)
130
120
Recommended
Capacity
Range
10 -100%
110
100
Recommended
Capacity
Range
50 -100%
90
Recommended
Capacity
Range
75 -100%
80
70
60
50
40
-20
-10
0
10
20
30
Evaporating Temperature (°F)
Figure 5
© 2012 Emerson Climate Technologies, Inc.
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50
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15 Second Operating Cycle
Compressor Capacity (Percent of Full Load)
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
0
1
2
3
4
5
6
7
8
9
Solenoid On-Time (Seconds)
Figure 6
Compressor Capacity Graph
*.ppt 3/23/2010 3:14 PM 1
Figure 7
Discharge Thermistors
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Arrow on valve
Must point to suction
Figure 8
3 to 7.5 Ton Modulation Valve Piping
Solenoid Valve
Discharge Manifold
Assembly
Suction Gas
Equalization
Manifold
Oil Equalization
Line
Suction
Manifold
Assembly
Figure 9
3 To 7.5 Ton Tandem
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Start
Is the compressor
running?
No
Yes
Yes
Allow time to cool
WARNING!
Disconnect and lockout
the power before
proceeding
Put the system back into
operation and retest
Remove one wire from
the modulation coil
No
Perform troubleshooting
to determine why the
compressor isn’t
running
Observe the compressor
suction & discharge
pressures
Are pressures
changing with the
modulation
cycle?
Is the compressor
overheated?
Yes
Operation
is normal
Measure the resistance
of the coil
No
Measure the voltage at
the modulation coil
terminals
Coil has continuity
and isn’t grounded?
No
Replace modulation
coil
Yes
Is voltage present,
coinciding with the
modulation cycle?
No
Replace modulation
valve, follow valve
replacement
instructions
Troubleshoot the
modulation control
Yes
Figure 10
Modulation Troubleshooting
© 2012 Emerson Climate Technologies, Inc.
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Put the system back into
operation and retest
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Table 1
Copeland Scroll Digital Family Features
Model
Digital
Modulation
Valve
Discharge Gas Temperature
Protection
Discharge
Check
Valve
Internal
Pressure
Relief (IPR)
Valve
No
Yes
Yes
No
Modulation
Control
ZPD34-54K5
ZRD36-48KC
ZPD61-91KC
Required
Accessory
ZRD61-81KC
External Sensor Required
Internal Top Cap Thermistor
ZPD103-182KC
Installed On
Compressor
ZRD94-125KC
External Sensor Required
Table 2
Refrigerant Charge Limits
Charge Limit
Model
Pounds
kg
ZPD34-54K5
8
3.6
ZPD61-91KC
10
4.8
ZPD103-137KC
16
7.2
ZPD154-182KC
18
8.2
ZPDT12-18MC
12
5.4
ZPDU13MC
12
5.4
ZPDT21-27MC
24
10.9
ZPDT31-36MC
27
12.2
ZRD36-48KC
8
3.6
ZRD61-81KC
10
4.8
ZRD94-125KC
16
7.2
ZRDU11-13MC
12
5.4
ZRDT12-16MC
12
5.4
ZRDT25MC
27
12.2
Table 3
Torque Values
Torque
Part
Modulation Valve
(ZPD103-182KC & ZRD94-125KC)
Solenoid Coil Screw
© 2012 Emerson Climate Technologies, Inc.
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Inch-Pounds
18.8-19.5
225-235
1.9-2.3
22.5-27.5
15 Second
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Table 4 – Compressor Accessories
Part
Category
Modulation
Part Description
Part Number
Models
Copeland Scroll Digital
Compressor Controller
943-0024-01
All
For OEM applications
Emerson Commercial Comfort
Controller
943-0175-00
All
For retrofit applications
Modulation Valve & 24V Coil
998-0061-19
24V Coil Only
023-0060-18
110V Coil Only
TBD
220V Coil Only
TBD
Modulation Valve, 24V Coil,
Tubing Kit
998-0090-02
Modulation Valve & Tubing Kit
998-0090-01
Modulation Valve
910-0109-00
24V Coil
998-0060-03
120V Coil
998-0060-04
200/220V Coil
998-0060-05
ZPD34-54K5
ZPD61-91KC
ZRD34-81KC
Notes
Tubing kit is for 7/8"
compressor suction; all coils
have 1/4" spade electrical
terminals
ZPD103-182KC All coils have 1/4" spade
ZRD94-125KC electrical terminals
Mounting
Crankcase
Heaters
Oil
Refer to the application engineering bulletins for the equivalent non-digital compressor model for
parts in these categories. Or, refer to the "service parts" section at www.EmersonClimate.com
Electrical
Tandems
985-0199-00
Diagnostics
Discharge Line Thermistor
& Protection
Retrofit Kits
985-0200-00
ZPD34-54K5
ZPD61-83KC
ZRD36-72KC
Fits 1/2" discharge tube
ZPD103-182KC
Fits 7/8" discharge tube
ZRD94-125KC
085-0204-00
ZPD91KC
ZRD81KC
Requires clamp 032-0689-00,
fits any size tube
Commercial Comfort
Controller, Modulation Valve,
24V Coil, & Tubing Kit
980-7000-00
ZPD34-54K5
ZPD61-91KC
ZRD36-48KC
ZRD61-81KC
Thermistor 085-0204-00 and
clamp 032-0689-00 must
be used with ZRD81KC and
ZPD91KC applications
Commercial Comfort
Controller, Discharge
Thermistor, & 24V Coil
980-7000-01
ZPD103-182KC
ZRD94-125KC
The contents of this publication are presented for informational purposes only and they 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. reserves the right to modify the designs or specifications of such products at any time without
notice. Emerson Climate Technologies, Inc. does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of
any Emerson Climate Technologies, Inc. product remains solely with the purchaser and end-user.
© 2012 Emerson Climate Technologies, Inc.
Printed in the U.S.A.
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