Copeland Screw Compressors

Semi-Hermetic Compact
Operating Instructions
SCH2 & SCA2
High Temperature Compressors
35-240 Horsepower

©2002 Copeland Corporation

1. Introduction

This series of semi-hermetic compact screw

compressors is designed for high and medium
temperature applications such as air conditioning
and commercial, industrial applications including
chillers, etc. These compressor models are of a
semi-hermetic design complete with an integral oil
separator. A typical installation may include one (1)
or two (2) in parallel, compact screw compressors
for an individual cooling circuit. Varying motor
voltages for both 50 and 60 Hz are available as well Figure 1
as numerous accessories. Mounting Pad Installation

Safety Notes The installation of the anti-vibration mounting pads

is shown in Figure 1. The bolts should only be
• All work on compressors, air conditioning and tightened so that deformation of the upper rubber
refrigeration systems should be carried out by disc is just visible.
qualified and authorized personnel only.
3.2 Piping Considerations
• Compressors are shipped with a holding charge
that is approximately 7.0 to 14.0 psi above Pipe Connections
atmospheric pressure.
The pipe connections are designed for tubing having
• During normal operation of the compressor nominal “SI” or “Imperial” dimensions. Solder con-
surface temperatures in excess of 212°F and nections have stepped inside diameters, the size of
below 32°F can be obtained, adequate the tubing determines how far it can be
personnel protection measures need to be inserted into the fitting. If desired, the unused
taken. (larger diameter) sections of the fitting can be
trimmed off.

2. Lubricant Types Pipe Runs

Refrigerant
Application
Oil type Use only tubing and components that are delivered
Range with an airtight seal which are clean and dry inside,
HFC H/M Solest 170 free from oxidation, slag and phosphate coatings.
The recommendations in the application manual No.
R22 H/M CP4214-320 4-1322 must be observed. Pipelines should be run
so that they cannot be flooded with oil or liquid
H – High Temperature, Air conditioning refrigerant during shut down periods. Connecting
M – Medium Temperature, Chiller applications piping for the optional refrigerant injection in to the
ECO port must initially include a vertical riser (mini-
3. Installing Equipment mum 6 inches) from the injection port on the com-
pressor to avoid oil migration and damage of com-
3.1 Mounting ponents through hydraulic peaks. See Figure 2 and
recommendations in the application manual. It is
The compressor must be installed horizontally. recommended, with larger volume systems, that
The use of anti-vibration mounting pads is recom- generously sized connections (evacuation points)
mended to reduce the transmission of noise with shut-off valves be installed in the suction and
and vibrations. The anti-vibration mounting pads are discharge lines, as well as sections that are isolated
included but packed separately from the compres- by a check valve.
sor. With direct mounting on water-cooled condens-
ers the use of anti-vibration mounting is essential in
order to prevent possible stress fracturing of the
heat exchanger tubes.

©2002 Copeland Corporation

 Caution
Min 6 – 8” rise
The compressor is shipped with a holding
charge, the suction and discharge service
valves should remain
closed until you evacuate the system.

Start Unloading/Capacity Control

Figure 2 Control is accomplished electrically via the sole-
Direct Refrigerant Injection Connection noid valves located on the side of the compressor.

Suction gas CR1

CR2

CR3

CR4
Oil pressure
Eco
Discharge gas

Figure 3
Oil (Hydraulic Scheme

Control Sequence – Infinite Capacity Control

Control Sequence – 4-Step Capacity Control
Minimum Capacity Í

CR 1 2 3 4
Start/Stop CR 1 2 3 4
Cap ⇑ Start/Stop
Cap ⇓ Cap 25% I
Cap ⇔ Cap 50% I
Cap. 100% Cap 75% I
Cap. Min.Í Cap. 100% I
Control Sequence – Infinite Capacity Control Solenoid Coil De-Energized
Minimum Capacity 50%
Solenoid Coil Energized
Cap ⇑ I Solenoid Coil Pulsing (10s on / 10s off)
Cap. Min.50%

©2002 Copeland Corporation

4. Electrical Connection Electronic Overload Relay

4.1 General Recommendations A UL approved overload relay of the self-powered,

heaterless design with phase loss protection (trips
The electrical installation should be done in within 3 seconds upon loss of one phase of a
accordance to the wiring diagram shown in the three-phase motor branch circuit) is required.
terminal box and in the application manual, in accor- Recommended features include;
dance to safety standards and local codes and
regulations. • Manual reset
• Voltage and frequency data on the nameplate • “Must hold amps” adjustment dial
should be compared to the electrical supply • Rated 50/60 Hz
data, the motor may only be connected when
these agree. An electronic overload relay is not included with
• The wiring of the motor terminals should be standard delivery of the compressors.
made according to the instructions on the
terminal box cover. Crankcase Heater

Caution The installation of a crankcase heater prevents

• Screw compressors may only be operated in dilution of the oil with refrigerant (reduced lubrication
one direction of rotation otherwise substantial properties) during long off-periods. Connect accord-
mechanical damage will occur in a very short ing to the schematic wiring diagram.
period of time.
Additional insulation of the oil separator may be
• Incorrect wiring of part-winding motors results in required with low ambient temperatures and for
opposing or displaced phase fields that lead to plants with a high temperature level on the high-
locked rotor conditions and the possibility of pressure side during off periods (e.g. heat pumps).
damage to the motor.
Monitoring the oil circuit
• The terminals 3 – 5 / T1-T2 on the compressor
and motor protection device must not come into There are two basic ways to monitor the oil level,
contact with the supply or control voltage. depending on the type of refrigeration circuit in-
volved.

Safety Note For short refrigeration circuits that do not employ

refrigerant injection for additional oil cooling and
The selection of the motor contactors, cables and for small volume systems with small refrigerant
fuses should be based on the maximum running charges, indirect monitoring of the oil can be em-
current and maximum power consumption (see ployed. By this method, the standard compressor
name plate and application manual). protection device electronic module monitors the
discharge temperature and the compressor is shut
4.2 Safety Devices down by excessive discharge temperature caused
by insufficient oil.
Compressor Protection Device INT69VSY-II/SE-E1

The compressor protection device For systems with refrigerant injection for additional
is mounted in the terminal box and is factory wired. oil cooling and/or systems with greater refrigerant
charges, direct monitoring is accomplished by
The compressor protection device monitors: means of an oil level control (optional item, supplied
• Winding Temperature separately Copeland Part no. 039-0008-00).
• Discharge gas temperature
• Direction of rotation / phase sequence High and Low Pressure Controls
• Cable break in the PTC sensor circuit
These are safety switches that are necessary to
Note: Transition to the SE-E1 compressor protec- maintain the system operating pressures within
tion device starting January 2004 desirable operating limits.

©2002 Copeland Corporation

5. Commissioning 5.3 Checks Before Starting

Pre-commissioning and commissioning checks and • Visual (safety) check of compressor/system.

testing should be carried out.
• Compressor oil level
5.1 Pressure Test / Evacuation / Leak Testing
• Safety features/devices are all in position,
Pressure test the system with dry nitrogen. If the calibrated and tested.
refrigeration system is tested with dry air the com-
pressor must be isolated and not included in the • Service valves are in the correct running
test. Evacuate the entire system including the position.
compressor and sections isolated by check valves.
• Check the set point values of the timing
• The crankcase heater should be switched on relays
during evacuation.
• Oil temperature in the oil separator should be
• 1000 micron standing vacuum should be more than 27°F above the ambient temperature
attained and held. (measured near the bottom of the oil separator).

• Repeat several times if required. 5.4 Starting

Leak test the system once it is charged with Check the Direction of Rotation
refrigerant (static and dynamic tests).
Caution

Caution Screw compressors may only be operated in one

Never start the compressor under vacuum. direction of rotation otherwise substantial
mechanical damage will occur.

Although the phase field is monitored by the

5.2 Refrigerant Charging compressor protection device, the following test is
recommended:
• Switch on the crankcase heater.
• Connect a compound gauge to the suction ser-
• Following the correct codes of practice, charge vice valve, fully front seat the suction service
the system with refrigerant as a vapor, liquid valve and then open one full turn.
or blend, by whichever method is necessary
according to type of refrigerant, system • Bump start the compressor - switch on then
design and size of the system. off quickly (approximately 0.5 to 1 second).

If the direction of rotation is correct the suction

pressure will drop immediately. A rise in suction
Caution pressure or a cut-out of the rotation protection
device will indicate a wrong direction of rotation. If
Refrigerant blend charging can cause “wet” com- this happens change over two electrical phases
pression therefore controlled charging is neces- at the terminals of the common supply line
sary with a discharge temperature at least 50°F
above condensing temperature. Start
Insufficient refrigerant charge causes low suction
pressure and high superheating (Be careful to Start the compressor again and slowly open the
remain within the operating limits of the suction service valve.
compressor).

©2002 Copeland Corporation

Oil Level Check When compressor or motor damage occurs an acid
test should be made. When required, clean up
• The oil level should be seen through the sight measures must be initiated, such as the installation
glass when the compressor is operating, the of an acid retaining suction side filter, purging of the
oil level can vary slightly in the sight glass system from the highest point on the discharge side,
as the compressor loads and unloads. or an oil change.

Caution Note: The oil must be drained out of the stator

housing and the compressor It may be
The discharge gas temperature must be at least necessary to repeat these measures.
54°F above the condensing temperature.
Caution
Setting the High and Low Pressure Switches

These devices should be set in accordance with Ester oils such as Solest 170 are extremely hygro-
the application limits. They should be set based scopic careful handling is required. Moisture is
on specific system operating parameters. chemically bonded with these oils and cannot, or
only insignificantly, be removed by evacuation.
Check Operating Data Dispose of waste oil in an ecologically way (chlor-
itic oil is pollutive waste).
• Evaporation temperature
Maintenance and Repair
• Suction gas temperature
Screw compressors do not have any valves and are
• Condensing temperature
therefore relatively maintenance free. However the
following points should be regularly checked:
• Discharge gas temperature, minimum 54°F
above condensing temperature maximum
• Operating data
212°F
• Oil supply (see section 5.5)
For application limits see page 7.
• Safety devices
Setting the Condenser Pressure Control
• Integrated check valve. After shut down the
The setting must be made so that the minimum
compressor runs backward for a short time,
pressure differential (at least 70 psid) is reached
until the pressure in the oil separator and the
within 20 seconds. A rapid reduction in pressure
compressor suction equalizes. When the check
must be avoided by employing a finely calibrated
valve is dirty or faulty this period of backward
pressure control.
rotation increases and the valve must be re-
placed. Access to the check valve is accom-
Vibrations
plished by removing the discharge service valve
The entire system as well as the pipe runs (espe- in the gas outlet of the compressor.
cially the small diameter pipes) must be checked
for abnormal vibrations. If necessary, additional
supports or dampers must be installed.

Oil Change

The oil types listed in section 2 are characterized by

a high degree of stability. If the system is correctly
manufactured or if fine filters are installed on the
suction side an oil change is not normally needed.

©2002 Copeland Corporation

 Application Ranges

SCH2
SCA2

Indicates allowable operating range

with external oil cooler.
Note :Approval is on a case by
case basis only

Indicates allowable operating

range with liquid injection

©2002 Copeland Corporation

 Technical Data
SCA2 – R134a Optimized Compressors
Compressor Motor Displacement Oil Weight Inlet Outlet Capacity RLA MCC
Type H.P. CFH Charge Lbs. Connection Connection Control Voltage RLA PWS/DOL R-134a
Fl. Oz. ODS ODS Range
SCA2-350E-FWC 208-230 112 286 / 535 126
SCA2-350E-FWD 35 5,830 304 699 2 1/8” 1 5/8” 30 – 100% 460 56.1 136 / 254 62.8
SCA2-350E-TWE 575 44.9 108 / 203 50.2

©2002 Copeland Corporation

SCA2-400E-FWC 208-230 150 394 / 737 168
SCA2-400E-FWD 40 7,244 304 716 2 1/8” 1 5/8” 25 – 100% 460 75 176 / 329 84
SCA2-400E-TWE 575 60 141 / 263 67.2
SCA2-500E-FWC 208-230 206 466 / 743 231
SCA2-500E-FWD 50 8,410 507 1,043 3 1/8” 2 1/8” 35 – 100% 460 103 226 / 359 115
SCA2-500E-TWE 575 82.5 186 / 296 92.4
SCA2-600E-FWC 208-230 224 559 / 939 251
SCA2-600E-FWD 60 9,682 507 1,061 3 1/8” 2 1/8” 30 – 100% 460 112 267 / 449 125
SCA2-600E-TWE 575 89.5 212 / 357 100
SCA2-700E-FWC 208-230 240 669 / 1,021 269
SCA2-700E-FWD 70 10,989 507 1,076 3 1/8” 2 1/8” 25 – 100% 460 120 303 / 485 135
SCA2-700E-TWE 575 96.1 259 / 412 108
SCA2-800E-FWC 208-230 274 966 / 1,416 306
SCA2-800E-FWD 80 13,428 744 1,737 4 1/8” 3 1/8” 35 – 100% 460 137 433 / 632 153
SCA2-800E-TWE 575 109 346 / 505 123
SCA2-900E-FWC 208-230 289 1,053 / 1,522 324
SCA2-900E-FWD 90 15,300 744 1,753 4 1/8” 3 1/8” 30 – 100% 460 145 477 / 690 162
SCA2-900E-TWE 575 116 384 / 555 129
SCA2-11HE-FWC 208-230 331 1,250 / 1,807 371
SCA2-11HE-FWD 110 17,491 744 1,773 4 1/8” 3 1/8” 25 – 100% 460 166 563 / 814 186
SCA2-11HE-TWE 575 133 449 / 648 148
SCA2-12HE-FWC 208-230 406 1,434 / 2,072 455
SCA2-12HE-FWD 125 20,024 744 7,786 4 1/8” 3 1/8” 25 – 100% 460 203 663 / 958 227
SCA2-12HE-TWE 575 162 530 / 766 182
SCA2-14HE-FWC 208-230 438 1,612 / 2,336 438
SCA2-14HE-FWD 140 22,602 744 1,808 4 1/8” 3 1/8” 25 – 100% 460 219 716 / 1,036 246
SCA2-14HE-TWE 575 175 577 / 835 196
SCA2-16HE-EWD 460 280 786 / 1,364*
160 26,212 947 2,712 5” 4 1/8” 25 – 100%
SCA2-16HE-EWE 575 224 628 / 1,091*
SCA2-18HE-EWD 460 310 831 / 1,442*
180 29,835 947 2,734 5” 4 1/8” 25 – 100%
SCA2-18HE-EWE 575 248 664 / 1,153*
SCA2-21HE-EWD 460 370 1,068 / 1,853*
210 34,310 947 2,867 5” 4 1/8” 25 – 100%
SCA2-21HE-EWE 575 296 854 / 1,482*
SCA2-24HE-EWD 460 420 1169 / 2029*
240 38,786 947 2,911 5” 4 1/8” 25 – 100%
SCA2-24HE-EWE 575 336 935 / 1623*
* Starting Currents based on Wye-Delta (Y∆) and Direct On Line (DOL) starting
 Technical Data
SCH2 – R-22 Compressors
Compressor Motor Displacement Oil Weight Inlet Outlet Capacity LRA MCC
Type H.P. CFH Fl. Oz. Lbs. ODS Connection Control Voltage RLA PWS/DOL R-22
ODS Range
SCH2-5000-FWC 208-230 145 498 / 939 162
SCH2-5000-FWD 50 5,830 304 716 2 1/8” 1 5/8” 30 – 100% 460 72 218 / 411 81
SCH2-5000-TWE 575 58 174 / 329 65
SCH2-6000-FWC 208-230 205 616 / 1,162 230
SCH2-6000-FWD 60 7,244 304 716 2 1/8” 1 5/8” 25 – 100% 460 102 269 / 508 115
SCH2-6000-TWE 575 82 215 / 406 92
SCH2-7000-FWC 208-230 251 607 / 1,015 280
SCH2-7000-FWD 70 8,410 507 1,076 3 1/8” 2 1/8” 35 – 100% 460 120 290 / 485 134
SCH2-7000-TWE 575 96 260 / 404 107
SCH2-8000-FWC 208-230 263 732 / 1,224 293
SCH2-8000-FWD 80 9,682 507 1,085 3 1/8” 2 1/8” 30 – 100% 460 126 350 / 585 140
SCH2-8000-TWE 575 101 279 / 433 112
SCH2-9000-FWC 208-230 305 885 / 1,435 341
SCH2-9000-FWD 90 10,989 507 1,103 3 1/8” 2 1/8” 25 – 100% 460 146 423 / 686 163
SCH2-9000-TWE 575 116 358 / 546 130
SCH2-11H0-FWC 208-230 355 1,375 / 1,988 398
SCH2-11H0-FWD 110 13,428 744 1,753 4 1/8” 3 1/8” 35 – 100% 460 178 619 / 895 199
SCH2-11H0-TWE 575 142 494 / 713 159
SCH2-12H0-FWC 208-230 396 1,577 / 2,279 444
SCH2-12H0-FWD 125 15,300 744 1,766 4 1/8” 3 1/8” 30 – 100% 460 198 729 / 1,054 222
SCH2-12H0-TWE 575 159 583 / 843 178
SCH2-14H0-FWC 208-230 449 1,773 / 2,569 503
SCH2-14H0-FWD 140 17,491 744 1,788 4 1/8” 3 1/8” 25 – 100% 460 224 788 / 1,139 251
SCH2-14H0-TWE 575 179 635 / 918 201
SCH2-18H0-EWD 460 321 515 / 1,546*
180 22,802 947 2,734 4 1/8” 3 1/8” 25 – 100%
SCH2-18H0-EWE 575 256 412 / 1,236*
SCH2-21H0-EWD 460 385 584 / 1,742*
210 26,212 947 2,778 4 1/8” 3 1/8” 25 – 100%
SCH2-21H0-EWE 575 308 467 / 1,393*
SCH2-24H0-EWD 460 420 667 / 2,000*
240 29,835 947 2,800 4 1/8” 3 1/8” 25 – 100%
SCH2-24H0-EWE 575 336 534 / 1,600*
* Starting Currents based on Wye-Delta (Y∆) and Direct On Line (DOL) starting

©2002 Copeland Corporation

 Technical Data
SCH2 – R-407C & R-134a Compressors

Compressor Motor Displacement Oil Weight Inlet Outlet Capacity LRA MCC MCC

©2002 Copeland Corporation

Type H.P. CFH Fl. Oz. Lbs. ODS Connection Control Voltage RLA PWS/DOL R-407C R-134a
ODS Range
SCH2-500E-FWD 208-230 145 498 / 939 192 178
SCH2-500E-FWD 50 5,830 304 716 2 1/8” 1 5/8” 30 – 100% 460 72 218 / 411 96 89
SCH2-500E-TWE 575 58 174 / 329 77 71
SCH2-600E-FWC 208-230 205 616 / 1,162 230 210
SCH2-600E-FWD 60 7,244 304 716 2 1/8” 1 5/8” 25 – 100% 460 102 269 / 508 115 105
SCH2-600E-TWE 575 82 215 / 406 92 84
SCH2-700E-FWC 208-230 251 607 / 1,015 264 262
SCH2-700E-FWD 70 8,410 507 1,076 3 1/8” 2 1/8” 35 – 100% 460 120 290 / 485 127 125
SCH2-700E-TWE 575 96 260 / 404 102 100
SCH2-800E-FWC 208-230 263 732 / 1,224 316 314
SCH2-800E-FWD 80 9,682 507 1,085 3 1/8” 2 1/8” 30 – 100% 460 126 350 / 585 152 150
SCH2-800E-TWE 575 101 279 / 433 122 120
SCH2-900E-FWC 208-230 305 885 / 1,435 351 349
SCH2-900E-FWD 90 10,989 507 1,103 3 1/8” 2 1/8” 25 – 100% 460 146 423 / 686 169 167
SCH2-900E-TWE 575 116 358 / 546 136 134
SCH2-11HE-FWC 208-230 355 1,375 / 1,988 375 382
SCH2-11HE-FWD 110 13,428 744 1,753 4 1/8” 3 1/8” 35 – 100% 460 178 619 / 895 188 191
SCH2-11HE-TWE 575 142 494 / 713 150 153
SCH2-12HE-FWC 208-230 396 1,577 / 2,279 421 423
SCH2-12HE-FWD 125 15,300 744 1,766 4 1/8” 3 1/8” 30 – 100% 460 198 729 / 1,054 211 212
SCH2-12HE-TWE 575 159 583 / 843 169 169
SCH2-14HE-FWC 208-230 449 1,773 / 2,569 463 459
SCH2-14HE-FWD 140 17,491 744 1,788 4 1/8” 3 1/8” 25 – 100% 460 224 788 / 1,139 232 229
SCH2-14HE-TWE 575 179 635 / 918 185 184
SCH2-18H0-EWD 460 321 515 / 1,546*
180 22,802 947 2,734 4 1/8” 3 1/8” 25 – 100%
SCH2-18H0-EWE 575 256 412 / 1,236*
SCH2-21H0-EWD 460 385 584 / 1,742*
210 26,212 947 2,778 4 1/8” 3 1/8” 25 – 100%
SCH2-21H0-EWE 575 308 467 / 1,393*
SCH2-24H0-EWD 460 420 667 / 2,000*
240 29,835 947 2,800 4 1/8” 3 1/8” 25 – 100%
SCH2-24H0-EWE 575 336 534 / 1,600*
* Starting Currents based on Wye-Delta (Y∆) and Direct On Line (DOL) starting
©2002 Copeland Corporation
 Form No. 2001CC-71 R2
Revised 3/04
Emerson Cliamte Technologies and the Emerson Climate Technologies logo are
trademarks and service marks of Emerson Electric Co. Copeland is a registered
trademark and Copeland Screw is a trademark of Copeland Corporation.
©2002 Copeland Corporation Printed in the U.S.A. © 2004 Copeland Corporation.