Copeland YAD K1 Series User manual

© 2023 Copeland LP
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IMPORTANT SAFETY INFORMATION.................2
Responsibilities,Qualifications and Training..................2
Terminal Venting and Other Pressurized System
Hazards.............................................................................3
Flammable Refrigerant Hazards......................................3
Electrical Hazards.............................................................3
Hot Surface and Fire Hazards..........................................3
Lifting Hazards..................................................................3
POE Oil Hazards................................................................3
Precautions.......................................................................3
Signal Word Definitions...................................................4
INTRODUCTION................................................5
Nomenclature...................................................................5
Digital Compressor Operation.........................................5
How itWorks....................................................................5
APPLICATION CONSIDERATIONS .....................5
Operating Envelope.........................................................5
Scroll Temperature Protection........................................6
Shell Temperature............................................................6
Pressure Fluctuations.......................................................6
Long Pipe Lengths / High Refrigerant Charge ................6
Suction and Discharge Fittings........................................7
System Tubing Stress.......................................................7
Solenoid Valve and Coil....................................................7
Accumulators....................................................................7
Off-Cycle Migration Control............................................7
Crankcase Heaters............................................................7
Pump Out Cycle................................................................7
Reversing Valves...............................................................7
Start Up and ShutDown..................................................8
Discharge Check Valve.....................................................8
Compressor Cycling..........................................................8
Sound Characteristics.......................................................9
High Pressure Control......................................................9
Low Pressure Control.......................................................9
Contaminant Control.......................................................9
Oil Type.............................................................................9
Power Factor..................................................................10
Manifolded Compressor Replacement.........................10
Modulation Control........................................................10
APPLICATION TESTS...................................... 10
Performance Modeling..................................................11
Refrigerant Flow Control...............................................11
ASSEMBLY LINE PROCEDURES ..................... 11
Assembly Line Brazing Procedure.................................11
Unbrazing System Components....................................11
Removing Compressors.................................................12
Pressure Testing.............................................................12
Assembly Line System Charging Procedure .................12
'Hipot' (AC High Potential) Motor Testing....................12
Final Run Test.................................................................12
SERVICE PROCEDURES.................................12
Field Replacement..........................................................12
Removing Oil...................................................................13
Electrical..........................................................................13
Compressor Replacement After a Motor Burn............13
Manifolded Compressor Replacement.........................13
Start-Up of a Newor Replacement Compressor..........13
Modulation Troubleshooting........................................13
Refrigerant Retrofits......................................................14
Modulation Valve ReplacementProcedure .................14
Modulation Valve ReplacementProcedure .................14
Copeland Scroll Compressor Functional Check............15
Figures & Tables.............................................16
Figure 1 - Scroll Tube Fitting Brazing............................16
Figure 2 –Digital Modulation Cycle..............................17
Figure 3 –Compressor Capacity Graph........................17
Figure 4: Digital Scroll Cross Section: YAD32-115 &
YPD76-129......................................................................18
Figure 5: Digital Scroll Cross Section: YAD130-174 &
YPD145-192....................................................................18
Figure 6: Operating Envelope: YAD32-50.....................19
Figure 7: Operating Envelope: YAD57-86.....................19
Figure 8: Operating Envelope: YAD98-115...................20
Figure 9: Operating Envelope: YAD130-174.................20
Figure 10: Operating Envelope: YPD76.........................21
Figure 11: Operating Envelope: YPD110-145...............21
Figure 12: Operating Envelope: YPD163-192...............22
Figure 13: Crankcase Heater Location: YAD32-50 .......22
Figure 14: Crankcase Heater Location: YAD57-115 &
YPD76-129......................................................................22
Figure 15: Crankcase Heater Location: YAD130 &
YPD145............................................................................23
Figure 16:CrankcaseHeater Location: YAD147-174 &
YPD163-192....................................................................23
Figure 17: Oil Dilution Chart..........................................24
Figure 18: Tandem Piping Example: YAD32-115 &
YPD76-129......................................................................24
Figure 19: Modulation Troubleshooting.......................25
Figure 20: Digital Nomenclature...................................25
Table 1: Torque Values..................................................26
Table 2: Compressor Features.......................................27
Table 3: Refrigerant Charge Limits................................27
TABLE OF CONTENTS
3-15 Ton YAD*K1 and YPD*K1 Copeland™Scroll Compressors
AE4-1491
October 2023

© 2023 Copeland LP
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AE4-1491
IMPORTANT SAFETY INFORMATION
Those involved in the design, manufacture, and installation of a system, system purchasers, and service personnel may
need to be aware of hazards and precautionsdiscussedin this sectionand throughoutthis document.OEMsintegrating
the compressor into a systemshould ensure that their own employees follow thisbulletin and provide anynecessary safety
information to those involved in manufacturing, installing, purchasing, and servicing the system.
Responsibilities, Qualifications and Training
•OEMs are responsible for system design, selection of appropriate components,integration of this componentinto the
system,and testing the system.OEMs must ensure that staff involved in these activities are competent and qualified.
•OEMs are also responsible for ensuring that all product, service, and cautionary labels remain visible orare appropriately
added in a conspicuouslocation on the systemto ensure they are clear to any personnel involved in the installation,
commissioning, troubleshooting or maintenance of this equipment.
•Only qualified and authorized HVAC or refrigeration personnel are permitted to install, commission, troubleshoot and
maintain this equipment. Electrical connections must be made by qualified electrical personnel.
•Observe all applicable standards and codes for installing, servicing, and maintaining electrical and refrigeration
equipment.
Terminal Venting and Other Pressurized System Hazards
If a compressor’s electrical terminal pin loses its seal,pressurized oil, refrigerant, and debris mayspray
out. This is called “terminal venting”.
The ejected debris,oil, and refrigerantcan injure people or damage property. The oil and refrigerantspray
can be ignited by electrical arcing at the terminal or any nearby ignition source, producing flames that may project a
significant distance from the compressor. The distance depends on the pressure and the amount of refrigerant and oil
mixture in the system. The flames can cause serious or fatal burns and ignite nearby materials.
Each compressor hasa terminal cover ormolded plug thatcovers electrical connections. The cover orplug helpsto protect
against electricshock and the risks of terminal venting. If terminal venting occurs, the cover or plug helps contain the spray
of refrigerant and oil and reduces the risk ofignition. If ignition occurs, the plug or cover helpscontain the flames. However,
neither the terminal cover nor the molded plug can completely eliminate the risk of venting, ignition, or electric shock.
See https://www.copeland.com/en-us/training-support/safety-resource-center/terminal-venting for more details about
terminal venting.
Additionally, a compressor’s refrigerant lines keep refrigerant and oil under pressure. When removing or recharging
refrigerant from this component during service, this can pose a pressurized fluid hazard

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Flammable Refrigerant Hazards
If flammable refrigerant is released froma system, an explosive concentration can be presentin theair near the
system.If there is an ignition source nearby,a release of flammable refrigerantcan result in a fire or explosion.
While systems using flammable refrigerant are designed to mitigate the risk of ignition if the refrigerant is
released, fire and explosion can still occur.
See https://www.copeland.com/en-us/training-support/safety-resource-center/flammable-refrigerantsfor more information
on flammable refrigerant safety.
Electrical Hazards
Until a system is de-energized, and capacitors have been discharged, the systempresents a risk of electric
shock.
Hot Surface and Fire Hazards
Whilethesystemis energized,and forsometimeafterit is deenergized,thecompressormaybehot. Touching
the compressor before it has cooled can result in severe burns. When brazing systemcomponents during
service, the flames can cause severe burns and ignite nearby combustible materials.
Lifting Hazards
Certain systemcomponents may be very heavy. Improperly lifting systemcomponents or the compressor
can result in serious personal injury. Use proper lifting techniques when moving.
POE Oil Hazards
This equipment containspolyolester (POE) oils. Certain polymers (e.g., PVC/CPVC and polycarbonate) can be harmed if
they come into contact with POE oils. If POE oil contacts bare skin, it may cause an allergic skin reaction.
Precautions
•Always wear personal protective equipment (gloves, eye protection, etc.).
•Keep a fire extinguisher at the jobsite at all times.
•Keep clear of the compressor when power is applied.
-IMMEDIATELY GET AWAY if you hear unusual sounds in the compressor. They can indicate that terminal pin
ejection may be imminent. This may sound like electricalarcing (sizzling, sputtering or popping). However, terminal
venting may still occur even if you do not hear any unusual sounds.
•Never reset a breaker or replace a blown fuse without performing appropriate electrical testing.
-A tripped breaker or blown fuse mayindicatean electrical fault in the compressor. Energizing a compressor with an
electrical fault can cause terminal venting. Perform checks to rule out an electrical fault.
•Disconnect power and use lock-out/tag-out procedures before servicing.
-Before removing the terminal cover or molded plug, check that ALL electrical power is disconnected fromthe unit.
Make sure that all power legs are open. (Note: The system may have more than one power supply.)

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-Discharge capacitors for a minimum of two minutes
-Alwaysusecontrolofhazardousenergy(lock-out/tag-out)procedurestoensurethatpowerisnotreconnectedwhile
the unit is being serviced.
•Allow time for the compressor to cool before servicing.
-Ensure that materials and wiring do not touch high temperature areas of the compressor.
•Keep all non-essential personnel away from the compressor during service.
•Remove refrigerant from both the high and low sideof the compressor. Use a recovery machineand cylinder designed
for flammable refrigerants. Do not use standard recovery machines because they contain sources of ignition such as
switches,high and low pressure controls,and relays.Only vent the refrigerant into the atmosphere if the system is in a
well-ventilated area.
•Never us a torch to remove the compressor. Only tubing cutters should be used.
•Use an appropriate lifting device to install or remove the compressor.
•Neverinstall a system and leave it unattended when it hasno charge,a holding charge,or with the service valves closed
without electrically locking out the system.
•Always wear appropriate safety glasses and gloves when brazing or unbrazing system components.
•Charge the system with only approved refrigerants and refrigeration oils.
•Keep POE oilsaway from certain polymers (e.g., PVC/CPVC and polycarbonate) and any other surface or material that
might be harmed by POE oils. Proper protective equipment (gloves, eye protection,etc.)must be used when handling
POE lubricant. Handle POE oil with care. Refer to the Safety Data Sheet (SDS) for further details.
•Before energizing the system:
1. Securely fasten the protective terminal cover or molded plug to the compressor, and
2. Check that the compressor is properly grounded per the applicable system and compressor requirements.
Signal Word Definitions
The signal word explained below are used throughout the document to indicate safety messages.
DANGERindicatesahazardous situation which, if not avoided, will result in death or
serious injury.
WARNING indicates a hazardous situation which,if not avoided, could result in death or
serious injury.
CAUTION, used with the safety alert symbol, indicates a hazardous situation which, if not
avoided, could result in minor or moderate injury.
DANGER
WARNING
CAUTION

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INTRODUCTION
The 3-to-15-ton YAD (R454B) & YPD (R32) Copeland
Scroll Digital™are variable capacity compressors that
can mechanically modulate.Digital scrolls are suitable
for a variety of applications where a variable capacity
compressor is needed. This bulletin describes the
operating and application differences with respect to the
equivalent fixed capacity Copeland Scroll™
compressors.Forcompressoraccessoriesand service
parts, please refer to Copeland Mobile.
Reference the AE4-1430 CompressorMultiples bulletin
for multiple compressor applications. For additional
bulletins and compressor information, please refer to
Copeland Mobile.
Nomenclature
The model number of the Copeland Scroll Digital
compressors includesthe approximate nominal 60 Hz
capacity at the AHRI high temperature full load air
conditioning rating point. An example is the
YAD174K1E-TFD, which has approximately 174,000
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.
Pleasereferto Figure20forabreakdownofCopeland
Digital Nomenclature.
Digital Compressor Operation
The digitalscrollis capableofseamlesslymodulatingits
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
full capacity, or loaded state.When the solenoid valve
is energized, the two scroll elements move apartaxially,
or into the unloaded state.During the unloadedstate,
the compressor motor continues running, butsince 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 ofthe
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.
Anexampleforthe15secondcontrollercycle:Inany15
second cycle, if the loaded time is 10 secondsand the
unloaded time is 5 seconds, the average capacity is
66%orif theloadedtimeis5secondsand theunloaded
time is 10 secondsthe capacity during that 15 second
period is 33%. See Figure 2 for a graphical
representation of the digital cycle, and Figure 3 for a
graph showing solenoid on-time vs. compressor
capacity.
It’s important to test at minimum modulation rates to
verify proper motor cooling and oil return. The
compressorcanoperate at10% modulation, but testing
is needed to determinehowlong this is acceptable in
the system. Operating conditions, superheat levelsand
system designs will affect the acceptable minimum
modulation rate in the system. It’s common to set the
minimum modulation rate at a higher percentage to
verify proper motor cooling and oil return.
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
YAD32-115 and YPD76-129 compressors described in
this bulletin use a liftpiston mechanismto 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.
The YAD130-174 and YPD145-192 compressors
employ a solenoid valve that is mounted on the side of
the compressor thatvents the intermediatecavity to the
low side of the compressor during the unloaded state.
During the loaded state the solenoid valve is de-
energized, and the intermediate cavity is pressurized to
load the floating seal and scrolls axially.
Please refer to Figures 4 and 5for cross sectional
pictures of the two digital modulation mechanisms.
APPLICATION CONSIDERATIONS
Operating Envelope
Figures 6 through 12 illustrate the operating
envelopesforthe YA & YP digital scroll compressors.
The operating envelopes represent operating
conditionswith 20°F (11K) superheat in the return gas
unless otherwise shown. The steady-state operating
condition of the compressor must remain inside the

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prescribed operating envelope.Excursions outside of
the envelope should be brief and infrequent.
The discharge temperature should be monitored to
prevent the compressor from overheating. The
compressor must not operate above maximum
dischargelinetemperature.Thesystemcanpotentially
decrease the discharge linetemperature byincreasing
the modulation rate, reducing the superheat,
decreasing the condensing temperature and/or
increasing theevaporatingtemperature.Theoperating
conditions, modulation rate, amount of time at a low
modulation rate and ambient temperature will impact
the discharge line temperature. Low modulation rates
for periods of time may result in insufficient motor
cooling. Testing is required to determine the
acceptableminimummodulation rate to ensure proper
discharge line temperatures, motor cooling and oil
return.
Scroll Temperature Protection
A discharge line thermistor should be used with the
compressors fordischarge temperature protection. The
discharge line thermistor should be installed within 6”
(15cm) of the compressor and well insulated. The
maximum discharge line temperature should be no
greater than 275֯F (144֯C) within the operating envelope
unless otherwise noted in the operating envelope. For
enhanced protection, a lower discharge line
temperature limit may be used.
For the Copeland Digital Controller to operate properly
an NTC sensor must be attached to the compressor
discharge within 6” (15cm) of the compressor
discharge fitting. For best response the sensor should
be insulated. See Table 7 of AE8-1328 forthermistor
temperature vs.resistance values.Refer to Copeland
Mobile for part numbers of discharge line thermistors.
Shell Temperature
Compressor top cap temperatures can be very hot.
Care must be taken to ensure that wiring or other
materials which could be damaged by these
temperatures do not come into contact with these
potentially hot areas.
Compressors requiring certificationto the Pressure
Equipment Directive (PED): The nameplate will be
marked with a TS min which is defined as the minimum
allowable temperature. The nameplate will also be
marked with a TS max which is defined asthe maximum
allowable temperature(max designtemperature,highest
temp that can occur during operation or standstillof the
refrigeration systemor during test under test conditions,
specified bythemanufacturer). Please refer to Copeland
Mobile for more details.
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 no
observableeffectonthereliabilityofthecompressoror
system components. System component
manufacturers should be consulted to ensure the
proper application of their products.
Long Pipe Lengths / High Refrigerant Charge
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 digitalscrollcompressor
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.
Some systems may contain higher than normal
refrigerant charges. Systems with large reheat coils,
low ambient condenser flooding, or systems with
multiple heat exchangers are among some system
configurations that may require additional lubricant.
If the compressors have a sight glass for oil level
viewing, the oil level should always be checked during
OEM assembly, field commissioning, and field
servicing. An estimation of the amount of additional
lubricant to add to the compressor(s) when the circuit
charge exceeds20 pounds of refrigerant is as follows:
Single compressor application: 0.5 fluid ounce ofoil per
pound of refrigerant.
Formultiplecompressorapplications,referto AE4-1430
for additional oil estimate for tandems and trios.
WARNING

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The oil level must be carefully monitored during system
development, and corrective action should be taken if
the compressor oil level falls below the minimum oil
level. The compressor oil levelshould be checked with
the compressor "off"to avoid the sump turbulence when
the compressor is running.
Some of these compressors are available to the OEM
with a production sight-glass that can be used to
determine the oil level in the compressor in theend-use
application. Some of these compressors are also
available to the OEM with an oil Schrader fitting on the
side of the compressorto add additional oil if needed
because of long lengths of piping or high refrigerant
charge. No attempt should be made to increase the oil
level in the sight-glass above the 3/4full level.A high oil
level is not sustainable in the compressor and the extra
oil will be pumped out into the system causing a
reduction in systemefficiency and a higher-than-normal
oil circulation rate.
Suction and Discharge Fittings
The compressors have copper plated steel suction and
discharge or threaded rotalockfittings. See Figure 1 for
assemblylineand field brazing recommendationsand
Table 1 for rotalock torque requirements.
System Tubing Stress
System tubing should be designed to keep tubing
stresses under the endurance limit of the coppertubing
type used (i.e., Type K,L, etc.). Start, stop and running
(resonance) cases should be evaluated to ensure long
term reliability.
Solenoid Valve and Coil
The external solenoid valve and coil specified by
Copeland 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
replacementpartsspecifiedinCopelandMobile. Refer
to the Service Procedures section for information on
changing the modulation valves.
Accumulators
The use of accumulators is very dependent on the
application.The Copeland scroll compressor’s inherent
ability to handle liquid refrigerant during occasional
operating flood back situations make the use of an
accumulator unnecessary in most applications. The
OEM is responsible for determining if an accumulator is
needed and the selection of the accumulator.
Consideration for additional oil needed for the
accumulator should be taken.
Off-Cycle Migration Control
Excessive migration of refrigerant to the compressor
during the off-cycle can result in oil pump-outon start
up, excessive starting noise and vibration, bearing
erosion, and broken scrolls if the hydraulic slugging
pressure is high enough. For these reasons, off-cycle
refrigerant migrationmustbe minimized. The following
three sections summarize off-cycle migration
techniques.
Crankcase Heaters
A crankcaseheaterisrequired when the system charge
exceeds the valueslisted in Table 3. This requirement
is independent of system type and configuration. The
initial start-up in the field is a very criticalperiod 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 hoursprior to starting the
compressor. This will help prevent oil dilution and
bearing stress on initial startup.
To properly install the crankcase heater, the heater
should be installed in the location illustrated in Figures
13-16. Tighten the clamp screw carefully, ensuring that
the heater is uniformly tensioned along its entire length
and that the circumference of the heater element is in
complete contact with the compressor shell. It's
important that the clamp screw is torqued to the range
shown in Table 1 to ensure adequate contact and to
prevent heaterburnout. Neverapplypowerto theheater
in free air or before the heater is installed on the
compressor to prevent overheating and burnout.
Crankcase heaters must be properly grounded to
reduce the potential of a fire or shock hazard.
Pump Out Cycle
A pump out cycle has been successfully used by some
manufacturers of large rooftop units. After an extended
off period, a typical pump out cycle will energize the
compressor for up to one second followed by anoff time
of 5 to 20 seconds. This cycle is usually repeated a
second time,the third time the compressor stayson for
the cooling cycle. If pump out cycle is employed, a
crankcase heater must be used if the circuit charge
amount exceeds the values listed in Table 3.
Reversing Valves
Since Copeland scroll compressors have very high
WARNING

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volumetricefficiency,theirdisplacementsarelowerthan
those of comparable capacity reciprocating
compressors.
Reversing valve sizing must be within the guidelines of
the valve manufacturer. Required pressure drop 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 resultin a valve not shifting. This can resultin
a condition where the compressor appears to be not
pumping (i.e.,balancedpressures). It canalso result in
elevated compressor sound levels.
During a defrost cycle, when the reversing valve
abruptly changes the refrigerant flow direction, the
suction and discharge pressureswill go outside of the
normal operating envelope. The sound that the
compressor makes during this transition period is
normal,and thedurationofthesoundwilldependonthe
coil volume, outdoor ambient temperature,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 should be evaluated.
The reversing valvesolenoidshouldbewired sothatthe
valve does not reverse when the system is shut off by
the operating thermostat in the heating orcooling mode.
If the valve is allowed to reverse at system shutoff,
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 durabilitybut can cause unexpected sound
after the compressor is turned off.
Start Up and Shut Down
To improve the starting characteristics of the digital
scroll compressor, the Copeland 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 shutting
down.
Since Copeland scroll compressors are also excellent
gas expanders, they may run backwards for a brief
period after shutdown as the internal pressures
equalize.
Discharge Check Valve
The YAD32-115 and YPD76-129 compressors include
a lowmass, disktypecheck valveinthedischargefitting
of the compressor. The YAD130-174 and YPD145-192
compressors include a spring assist, disk-type check
valve in the discharge fitting of the compressor. The
check valve prevents the high pressure gas in the
condenser from rapidly flowing back through the
compressoraftershutdown. Thecheckvalveisnotleak-
proof. Performance of the check valves for recycling
pump down applications hasn't been evaluated at all
pressure differentials. Low pressure differentials may
result in unacceptable leak-back rates.
Compressor Cycling
There is no set answer to how often scroll compressors
can be started and stopped in an hour, since it is highly
dependent on system configuration. There is no
minimumofftimebecauseCopelandscrollcompressors
start unloaded, even if the system has unbalanced
pressures. The most critical consideration is the
minimum run time required to return oil to the
compressor after startup.
To establish the minimum run time, obtain a sample
compressor equipped with a sight tube (available from
Copeland) and install it in a system with the longest
connecting lines and highest internal volume that the
system mayhave. The minimum on time becomesthe
time required for oil lost during compressor startup to
return to the compressor sump and restore a minimaloil
level that will assure oil pick up through the crankshaft.
The minimum oil level required in the YAD32-50
compressors is 1.6" (40 mm) below the center of the
compressor sight-glass. The minimum oillevel required
in the YAD57-86 and YPD76 compressors is 1.4" (35
mm) below the center of the compressor sight-glass.
YAD98-115 and YPD110-129 compressors is 2.4" (60
mm) below the center of the compressor sight-glass.
The minimum oil level required in the YAD130-174 and
YPD145-192 compressors is 1.5” (40 mm) below the
center of the compressor sight-glass. The oil level
should be checked with the compressor "off" to avoid
the sump turbulence whenthe compressoris running.
Cycling thecompressorforashorterperiodthanthis, for
instance to maintainvery tight temperature control, will
result in progressive loss of oil and damage to the
compressor.
Because of the digital scroll's seamless capacity
modulation from 10%to 100%, capacity short cycling is

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lesscommonforsinglecompressors. Modulatingbelow
10% is not recommended due to possible motor
overheat and inadequate oil return. However, if the
digital compressor is in tandem with a non-modulated
scroll, short cycling of the non-modulated compressor
may be an issue if the systemcontrolis not designed
and set correctly. The digital controllers have a built in
two-minute anti-short cycle timer to prevent short
cycling.
Sound Characteristics
The sound spectrum of the loaded state and the
unloaded state are different. Special consideration
should be givento the transition soundbetweenthe
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 one source for scroll compressor
sound blankets.
The transition sound between the loaded and unloaded
states has no observable effect on compressor
components or reliability.
The Copeland controllers unload the compressor a
fraction of a second before shutting down allowing the
scroll set to unload, ensuring a relatively quiet
shutdown.
Internal Pressure Relief (IPR) Valve
High Pressure Control
A high-pressure control must be used in all
YAD130-174 and YPD145-192 applications
because these compressors do not have internal
pressure relief (IPR) valves.
The YAD130-174and YPD145-192compressors donot
have internal pressure relief valves. The system
designer should determine the required high pressure
value cutout for the desired systemand application. The
high pressure control should have a manual reset
feature for the highest level of system protection.
If any type of discharge line shut-off valve is used, the
high pressure control must be installed between the
compressor discharge fitting and the valve.
Compressors with rotalock discharge fittings have a
connectionon the rotalock fitting for the high pressure
cut-out switch connection. Refer to Table 2 for
compressor features.
Low Pressure Control
A low pressure control is highly recommended for loss
of charge protection and other systemfault conditions
that may result in very low evaporating temperatures.
Loss of system charge will result in overheating and
recycling of the motor overload protector. Prolonged
operation in thismanner could result in oilpump outand
eventual bearing failure. The low pressure cut-out
setting will depend on the application typeand minimum
expected evaporating temperature. The low pressure
cut-out should be selected based on the specific
applicationand expectedoperatingconditions. Acutout
setting no lower than 20 psig (1.4 bar) is recommended.
Contaminant Control
Manufacturing processes have been designed to
minimizetheintroductionofsolidorliquidcontaminants.
Dehydration and purge processes ensure minimal
moisture levels in the compressor, and continuous
auditing of lubricant moisture levels ensures that
moisture isn’t inadvertently introduced into the
compressor. However, due to the manufacturing
processes, Copeland scroll compressors will contain a
miniscule amount ofsolid and liquid contaminants when
they leave the factory.
During unit assemblyand field servicing, compressors
shouldn't be left open to the atmosphere forlonger than
five minutes. It is generally accepted that system
moisture levels should be maintained below 50 ppm. A
filter-drier is required on all POE lubricant systems to
prevent solid particulate contamination, oil dielectric
strength degradation,ice formation, oil hydrolysis, and
metal corrosion. It is the system designer’s responsibility
to makesure that the filter-drier is adequately sized to
accommodate the contaminants from system
manufacturing processes which leave solid or liquid
contaminants in theevaporator coil, condenser coil,and
interconnecting tubing plus any contaminants
introduced during the field installation process.
Molecular sieve and activated alumina are two filter-
drier materials designed to remove moisture and
mitigate acid formation. A 100% molecular sieve filter
can be used for maximum moisture capacity. A more
conservative mix, such as 75% molecular sieve and
25% activated alumina, should be used for service
applications.
Oil Type
Polyol ester oil (POE) is used in YA*K1, YA*K2 and
YP*K1 compressors. Please refer to Copeland
publication 93-11 available at Copeland Mobile for
specific POE oil grade in centistokes for each
refrigerant.
WARNING

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AE4-1491
See the compressor nameplate for the original oil
charge. A complete recharge should be approximately
four to six fluid ounces (118-177ml) less than the
nameplate value. Please refer to Copeland Mobile for
model specific oil charge and recharge values. If
additional oil is needed in the field, there are multiple
POE brands available at your local distributor and
wholesalers.
POE maycause an allergic skin reaction and 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 contactwith any surface or material that
might be harmed by POE, including without
limitation, certain polymers (e.g. PVC/ CPVC and
polycarbonate).RefertotheSafetyDataSheet(SDS)
for the specific oil available from Copeland Mobile.
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
to avoid problems associated with over correction. See
AE9-1249 for more information on power factor
correction.
Manifolded Compressor Replacement
Use care and the appropriate material handling
equipment when lifting and moving compressors.
Personal protective equipment must be used.
A crankcase into a tandem configuration in their
manufacturing plant. Drawingsofthe tandemmanifolds
are available by contacting your application engineer.
Figure 18 illustrates a typical tandem compressor
assembly using YAD32-115 and YPD76-129 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.
For more information, reference the AE4-1430
Compressor Multiples bulletin for multiple compressor
applications.
Modulation Control
Two different controls are available from Copeland to
provide digital scroll modulation control, the Copeland
Scroll Digital CompressorController, and the Copeland
Commercial Comfort Controller.
The Copeland ScrollDigitalCompressorControlleris an
open loop controller that provides control, protection,
and diagnostics for the digital scroll and is suited for
OEMapplications.Thesystemcontrollersuppliedbythe
OEM calculates the required compressorcapacity 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.
ForOEMs that choose theirowncontrolspackage, the
controls must include the protection features
incorporated into the Copeland Scroll Digital
Compressor Controller. Please consultwith Application
Engineering for a list of these requirements.
APPLICATION TESTS
The system designer is responsible for testing the
system to ensure it operates as designed. These tests
should be performed during system development and
are dependent on the system type and amount of
refrigerant charge. These application tests are to help
identify errors in system design that may produce
conditions that could lead to compressor failure.
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 should be observed and recorded also. Testing
conditionsshallinclude defrost and varying loads. If the
system is reversible, the tests should be conducted in
both operation modes.
System engineers should review the systemdesign and
operation to identify the criticalconditions and to check
oil return, oil balancingand liquid floodback.Typically,
the following situations should be considered:
▪In single compressor systems: to check oil return,
testing conditions shall be at minimum mass flow
condition, minimum modulation rate and minimum
density of suction gasin continuous and frequent start-
stop-cycling.
▪In multiple compressor systems: to check oil return
and oilbalancinginthetandemortrio,testingconditions
shall be at the corner pointsof thesystemapplication
WARNING

© 2023 Copeland LP
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AE4-1491
envelope in continuous and frequent start-stop-cycling.
▪In all systems: to test liquid floodback, all possible
transient operation conditions in the system should be
checked, 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, please
refer to the oil dilution chart inFigure 17.The oildilution
chart should be used if operating below9֯F superheat.
Liquid levelandsuperheatatcompressorsuctionshould
be checked.
Application Engineering is available to recommend
additional tests and to evaluate test results.
Performance Modeling
Copeland Climate Technologies, Inc. is not
responsible or liable for incorrect energy use
predictions.
Successful digital scroll retrofit projects, and resultant
energy savings, have been documented by several
industry energy groups. Predicting the energy usage
and calculatingareturnoninvestmentbeforetheproject
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. Tabularperformance data and
the ten coefficients forthe AHRI polynomial equation for
performance at 50% and 100% load are available for
modeling purposes at Copeland Mobile.
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. Expansion valves have varying turndown
limitations based on their rated capacity. Excessive
hunting and loss of superheat control can result when
asking an 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.
Proper testing is required to verify the expansionvalve
is properly controlling the superheat at various
modulation rates throughout the envelope.
ASSEMBLY LINE PROCEDURES
Assembly Line Brazing Procedure
The external modulation valve is purchased and
shipped separately fromthe YAD32-115 and YPD76-
129 compressors. The YAD130-174 and YPD145-192
compressors don’t require an external modulation
valve. Therefore, assembly is required in the OEM
manufacturing plant. Figure 5 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.
When brazing the modulation valveinto 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
donequicklysothevalveisn'toverheated.Thebrazing
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
theleads arekept away fromthebrazing operationand
the wet rag is able to fully contact the valve body.
Figure 1 discussesthe properprocedures for brazing
the suction and discharge lines to a scroll compressor.
It is importantto flownitrogen through the system while
brazing all joints during the system assemblyprocess.
Nitrogen displaces the air and prevents the formation of
copper oxides in the system. If allowed to form, the
copper oxide flakes can later be swept through the
system and block screens such as those protecting
capillary tubes, thermal expansion valves, and
accumulator oil return holes. The blockage - whether it
is of oil or refrigerant - is capable of doing damage
resulting in compressor failure.
Unbrazing System Components
Beforeattemptingtobraze, itisimportanttorecover
all refrigerant from both the high andlow side of the
system.
If the refrigerant charge is removed from a scroll-
equipped unit by evacuating the high side only, it is
possible for the scrolls to seal, preventing pressure
equalization through the compressor. This may leave
the low side shell and suction line tubing pressurized.
WARNING

© 2023 Copeland LP
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AE4-1491
Removing Compressors
Before attempting to cut copper tubing, it is
important to recover all refrigerant from both the
high and low side of the system.
Instructionsshould be provided in appropriate product
literature and assembly (line repair) areas. If a
compressor removal is required,the compressor should
be cut out of system rather than unbrazed.
Pressure Testing
Never pressurize the compressor to more than 475
psig (33 bar) for leak checking purposes. Never
pressurize the compressor froma nitrogen cylinder
or other pressure source without an appropriately
sized pressure regulating and relief valve.
The pressure used on the line to meet the U.L. burst
pressure requirementmust not be higher than 475 psig
(33 bar). Higher pressure may result in permanent
deformation of the compressor shell and possible
misalignment, bottom cover distortion and/or shell
rupture.
Assembly Line System Charging Procedure
Systems should be charged with liquid on the high side
to the extent possible. Most of the charge should be
pumped in the high side of the systemto prevent low
voltage starting difficulties,hipot motortest failures, and
bearing washout during the first-time start on the
assemblyline. If additional charge is needed,it should
be added as liquid to the low side of the systemwith the
compressor operating. Pre-charging on the high side
and adding liquid on the low side of the systemare both
meant to protect the compressor from operating with
abnormally low suction pressuresduring charging. Do
not operate the compressor without enough system
charge to maintain at least 55 psig (3.8 bar) suction
pressure. Do not operate the compressor with the low
pressure cut-out disabled. Do no operate with a
restricted suction or liquid line.
Depending on the discharge pressure, allowing
pressure to drop below 55 psig (3.8 bar) for more than
a fewsecondsmayoverheatthescrollsand causeearly
drive bearing damage.
Do not use the compressor to test the opening set
point of a high pressure cutout.
Bearings are susceptible to damage before they have
had several hours ofnormal running forproperbreak in.
'Hipot' (AC High Potential) Motor Testing
Use caution with high voltage and never hipot test
when compressor is in a vacuum.
Copeland scroll compressors are configured with the
motor down and the pumping components at the top of
the shell. As a result, the motor can be immersed in
refrigerant to a greater extent than hermetic
reciprocating compressors when liquid refrigerant is
presentintheshell.Inthisrespect,thescrollismorelike
semi-hermetic compressorsthat have horizontal motors
partially submerged in oil and refrigerant. When
Copeland scroll compressorsare hipot tested with liquid
refrigerant in the shell, they can show higher levels of
leakagecurrentthancompressorswiththemotorontop.
This phenomenon can occur with any compressor when
themotorisimmersedinrefrigerant.Thelevelofcurrent
leakage doesnot presentany safetyissue. To lower the
current leakage reading, the system should be operated
for a brief periodto redistribute the refrigerant to a more
normal configuration and the system hipot tested again.
See AE4-1294 for megohm testing recommendations.
Under no circumstances should the hipot test be
performed while the compressor is under a vacuum.
U.L. sets the requirement fordielectricstrength testing
and they shouldbeconsultedfortheappropriatevoltage
and leakage values.
Final Run Test
Customers that use a nitrogen final run test must be
careful to notoverheatthe compressor.Nitrogen is not
a good medium for removing heatfrom the compressor,
and the scroll tips can be easily damaged with high
compression ratios and/or long test times. Copeland
scroll compressorsare designed for use with refrigerant
and testing withnitrogen mayresult in a situation where
the compressor doesnotdevelop a pressure differential
(no pump condition). When testing with nitrogen, the
compressor must be allowed to cool for several minutes
between tests.
SERVICE PROCEDURES
Field Replacement
WARNING
CAUTION
CAUTION

© 2023 Copeland LP
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AE4-1491
Use care and the appropriate material handling
equipment when lifting and moving compressors.
Personal protective equipment must be used.
Removing Oil
If the oil level is higher than the oil Schraderfitting on
the sump of the compressor oil can be drained fromthis
fitting until theoil level reaches thelevel of the Schrader
fitting.To remove oil fromthe compressorwhen the oil
level is below the oil Schrader fitting one of two different
procedures can be used. The first procedure is to
remove the compressor fromthe systemand drain the
oil from the compressor suction connection. This
method ensures complete removal of the oil from the
compressor. The second procedure is to remove the
compressor sight-glass and insert a hose into the sump
of the compressor and drawthe oil outwith a hand-held
pump.
Electrical
When replacing a compressor, especially one that has
been in the field forseveral years, it is always a good
idea to replace the contactor.
Note: See the locked rotor on the nameplate of the new
compressor and make sure the contactor exceeds this
locked rotor rating.
Compressor Replacement After a Motor Burn
In the case of amotorburn, most of thecontaminated
oil will be removed with the compressor. The rest of the
oil is cleaned with the use of suction and liquid line filter
driers. A 100% activated alumina suction filter drier is
recommendedbutmustberemovedafter72hours.See
AE24-1105 for clean up procedures and AE11-1297 for
liquid line filter-drier recommendations.
It is highly recommended that the suction accumulator
be replaced if the system contains one.
This is because the accumulator oil return orifice or
screen may be plugged with debris or may become
plugged shortly after a compressor failure. This will
result in starvation of oil to the replacementcompressor
and a second failure.
Manifolded Compressor Replacement
Use care and the appropriate material handling
equipment when lifting and moving compressors.
Personal protective equipment must be used.
Should a compressor fail in a manifolded set, onlythe
failed compressor should be replaced and not both
compressors. The oil from the failed compressor will
stay mostly in the failed compressor. Anycontaminated
oil that doesenter the tandem circuit will be cleaned by
the liquid line filter drier, and when used, the suction line
filter drier.
The suction and discharge manifolds can be reused if
the failed compressor is carefully removed, and the
manifoldsarecut insuchawaythatacouplingand short
piece of copper can reconnect the new compressor.
Reference the AE4-1430 Compressor Multiples
Bulletin for more information on installing a new oil
equalization line.
Start-Up of a New or Replacement Compressor
It is good service practice,when charging a system with
a scroll compressor, to charge liquid refrigerant into the
high side only. It is not good practice to dump liquid
refrigerant froma refrigerant cylinder into the crankcase
of a stationary compressor. If additional charge is
required, charge liquid into the low side of the system
with the compressor operating.
Follow the unit manufacturer’s guidelines for
properly evacuatingand charging of the system. Do
not start the compressor while the system is in a
vacuum. Internal arcing may occur when any type
of compressor is started in a vacuum which may
result in terminal venting.
Do not operatethecompressorwithoutenoughsystem
charge to maintain at least 55 psig (3.8 bar) suction
pressure. Do not operate with a restricted suction or
liquid line.Do not operatewiththelowpressurecut-out
disabled. Allowing suction pressure to drop below 55
psig (3.8 bar) for more than a few seconds may
overheat the scrolls and cause early drive bearing
damage. Never install a system in the field and leave it
unattended with no charge, a holding charge, or with
the service valves closed without securely locking out
the system. This will prevent unauthorized personnel
from accidentally ruining the compressor by operating
with no refrigerant flow.
Modulation Troubleshooting
The modulation valve and solenoid coil are engineered
for specificuse with the digital scroll. Don’t attempt to
substitutereplacement solenoidcoilsthat are notof the
correct part number. The YAD32-115and YPD76-129
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
CAUTION

© 2023 Copeland LP
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AE4-1491
reversed, can result in sporadic operation of the
modulation valve.See Figure 4 for an illustration of the
correct valve location and orientation.
Figure 19 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.
Refrigerant Retrofits
Only use approved refrigerants, lubricants, and
parts in accordance with the system and
compressor specifications. Recover all the
refrigerant from the system includingthe high and
low side. Use a tubing cutter to remove the
compressor.
These compressors are UL recognizedanduse
with any other refrigerant than originally
intended for use will void the compressor UL
recognition. For a list of Copeland approved
refrigerants please refer to Form 93-11,
Refrigerants and Lubricants ApprovedforUse
in Copeland Compressors.
Modulation Valve Replacement Procedure
The YAD32-115and YPD76-129compressors
employ a modulation valve that is mounted
external to the compressorin the modulation
tubing. To replace themodulation valve, follow
these recommended steps:
1. Disconnect and lockout the power to the unit.
2. Recover the refrigerant charge from the
compressor/ system.
3. 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.
5. Using manifold gauges, double check to
make sure the refrigerant charge is
completely recovered from the compressor
before proceeding.
6. Using tubing cutters, cut the modulation tubing
close to the valve body leaving the valve tubing
stubs inthesuction'T' connectionand theswaged
tubing from the compressor top cap.
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 thetubing/suction 'T' fitting to be reused.
8. After these fittings have cooled,clean the fittings,
and prepareto brazethenewvalveinplace.Wrap
a wet rag around the valve body to keep from
overheating the valve.
9. Using standard brazing practicesfor refrigeration
systems, carefully braze the new valve into the
system, directing the torch flame away from the
valve body.
10. Check for leaks using nitrogen with a properly
sized regulating and relief valve.
11. Install the solenoid coil and torquethe retaining
screw to 25 in-lbs.
12. Evacuate the compressor/system and put the
system back into operation.
Modulation Valve Replacement Procedure
The YAD130-174and YPD145-192compressorshave
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:
1. Disconnect and lockout the power to the unit.
2. Recover the refrigerant charge from the
compressor/ system.
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 valvebody to prevent debris and
dirt fromentering the systemwhen changing the
valve.
5. Using manifold gauges, double check to
make sure the refrigerant charge is
completely recovered from the compressor
before proceeding.
6. Using a 7/8” deep well socket and ratchet, turn
the valve counterclockwise to remove the valve.
7. Visually inspect the valve receptacle on the
compressor for damage or debris. Ensure that
the black o-ring and white PTFE gasket are
removed with the valve and do notremain on the
valve receptacle.

© 2023 Copeland LP
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AE4-1491
8. The replacement valve should have a
new, black o-ring and white, PTFE
gasket as shown:
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.
10. Lightly oil the gaskets with refrigeration
oil and hand tighten the newmodulation
valve into the valve receptacle on the
compressor. 11. Using a 7/8” deep well
socketand a torque wrench, torque the
modulation valve to 310-332 in-lbs.
12. Checkforleaksusingnitrogenwithaproperly
sized regulating and relief valve.
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 putthesystemback
into operation.
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 lowthe compressor will pull
suction pressure is nota 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.
1. Proper voltage to the unit should be verified.
2. The normal checks of motor winding continuity
and short to ground should bemade to determine
if the inherent overload motor protector has
opened or if an internal motorshort 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/fanoperation
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 systemis
either low on charge or there is a flowblockage in
the system.
5. If suction pressure doesnot 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 pressuresstill
do notmove to normal values, either the reversing
valve (if so equipped) or the compressor is faulty.
Reconnect the compressor leads as originally
configured and use normaldiagnostic procedures
to check operation of the reversing valve.
The solenoid coil should only be energized
when it is installed on the solenoid valve.
Energizing the coil when it is not installedon
the valve will result in a failed coil.
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.
6. To test if thecompressoris 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 currentdeviates
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.
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 Copeland 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.

© 2023 Copeland LP
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AE4-1491
Figures & Tables
Figure 1 - Scroll Tube Fitting Brazing
New Installations
•The copper-coated steel tube fitting on scroll compressors can be brazed in
approximately the same manner as any copper tube.
•Recommended brazing materials:Any silfosmaterial is recommended, preferably
with a minimum of 5% silver. However, 0% silver is acceptable.
•Be sure suction tube fitting I.D.and suction tube O.D. are clean prior to assembly. If
oil film is present wipe with denatured alcohol, Dichloro-Trifluoroethane or other
suitable solvent.
•Using a double-tipped torch apply heat in Area 1. As tube approaches brazing
temperature, move torch flame to Area 2.
•Heat Area 2 until braze temperature is attained, moving torch up and down and
rotating around tube as necessary to heat tube evenly. Add braze material to the
joint while moving torch around joint to flow braze material around circumference.
•After braze materialflows around joint, move torch to heat Area 3. This will draw the
braze material down into the joint. The time spent heating Area 3 should beminimal.
•As with any brazed joint, overheating may be detrimental to the result.
Field Service
Remove refrigerant charge fromboth the low and high side of the compressor
before cutting the suction and discharge lines to remove the compressor. Verify
the charge has been completely removed with manifold gauges.
•To disconnect: Reclaimrefrigerant fromboth the high and low side of the system.
Cuttubing nearcompressor.Thecompressorshouldbedisconnectedusingatubing
cutter.
•To reconnect:
✓Recommended brazing materials: Silfoswith minimum 5% silver or silverbraze
material with flux.
✓Insert tubing stubsinto fitting and connect to the system with tubing connectors.
✓Follow New Installation brazing instructions above.

© 2023 Copeland LP
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AE4-1491
Figure 2 –Digital Modulation Cycle
Figure 3 –Compressor Capacity Graph
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
CompressorCapacity (Percent ofFull Load)
Solenoid On-Time (Seconds)
15 Second Operating Cycle

© 2023 Copeland LP
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AE4-1491
Figure 4: Digital Scroll Cross Section: YAD32-115 & YPD76-129
Figure 5: Digital Scroll Cross Section: YAD130-174 & YPD145-192

© 2023 Copeland LP
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AE4-1491
Figure 6: Operating Envelope: YAD32-50
Figure 7: Operating Envelope: YAD57-86

© 2023 Copeland LP
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AE4-1491
Figure 8: Operating Envelope: YAD98-115
Figure 9: Operating Envelope: YAD130-174