Copeland Screw Compressors Semi-Hermetic …

1 Copeland ScrewCopeland ScrewCopeland ScrewCopeland ScrewCopeland Screw CompressorsCompressorsCompressorsCompres sorsCompressorsSemi- hermetic compact Semi-Hermetic compact Semi-Hermetic compact Semi-Hermetic compact Semi-Hermetic compact Application ManualApplication ManualApplication ManualApplication ManualApplication Manual1 General1 General1 General1 General1 General2 Design and functions2 Design and functions2 Design and functions2 Design and functions2 Design and Design Compression process Vi Capacity control and start Hydraulic Starting the compressor2. 6 Infinite capacity controlOil circulation3 Lubricants3 Lubricants3 Lubricants3 Lubricants3 Lubricants4 Integration into the refrigeration circuit4 Integration into the refrigeration circuit4 Integration into the refrigeration circuit4 Integration into the refrigeration circuit4 Integration into the refrigeration Mounting the System Guide lines for special Additional cooling by liquid Additional cooling by external oilcooler5 Economizer operation5 Economizer operation5 Economizer operation5 Economizer operation5 Economizer Operation ECO operation with subcooling ECO operation with intermediatepressure Layout and selectionrecommendations5.

2 6 Additional Control6 Electrical connections6 Electrical connections6 Electrical connections6 Electrical connections6 Electrical Motor Selection of electrical compressor protection Schematic wiring diagramsAE4-1322 April 2002 SCH2 & SCA2 SCH2 & SCA2 SCH2 & SCA2 SCH2 & SCA2 SCH2 & SCA2 High Temp Compressors35 140 HorsepowerContents 2002 Copeland CorporationIssued 4-2002 Printed in AE4-1322 2002 Copeland CorporationIssued 4-2002 Printed in new series represents the result of further develop-ment to provide a simplified and favorably priced screwcompressor for use in factory made to the Semi-Hermetic and open type, SHM/SHL and SDM/SDL compressor models for commercialand industrial installation, the compact screws aredesigned with an integral oil separator. The effortinvolved in installation is therefore comparable with thatfor Semi-Hermetic reciprocating addition to this, the electrical control and the monitor-ing of the oil circuit has been simplified.

3 The provenbasic construction and the ease of service have most modern Screw compressor technology is nowavailable in the middle capacity range for compact liquidchillers and air conditioning Design and function2. Design and function2. Design and function2. Design and function2. Design and Design featuresCopeland compact screws are of the twin rotor designwith a newly-developed profile geometry (lobe ratio 5:6).The main parts of these Compressors are the two rotors(male and female rotor), which are fitted into a closedhousing. The rotors are precisely located at both endsin rolling contact bearings (radial and axial), which, inconjunction with the generously sized oil supplychambers, provides optimum emergency to the specific design, this type of compressordoes not require any working valves.

4 To protect againstreverse running when the compressor is switched off(expansion operation) a check valve is incorporated inthe discharge chamber (this valve does not, however,replace any check valves required by the systemdesign). An internal pressure relief valve is utilized forover-pressure compressor is driven by a three-phase asynchro-nous motor, which is built into the compressor motor rotor is located on the shaft of the malescrew rotor. Cooling is achieved by cold refrigerantvapor, which mainly flows through bores in the main technical features:Balanced product rangeBalanced product rangeBalanced product rangeBalanced product rangeBalanced product range 8 basic models Tight performance graduationMinimal space requirements and convenientMinimal space requirements and convenientMinimal space requirements and convenientMinimal space requirements and convenientMinimal space requirements and convenientpiping designpiping designpiping designpiping designpiping design Shortest installed length in its performance category- shut-off valves / connections within compressordimensions Suction and discharge gas connections can berotated in 90 increments Terminal box accessible from top.

5 Wire access fromunderneathUniversal applicationsUniversal applicationsUniversal applicationsUniversal applicationsUniversal applications R134a, R407C and R22 R404A, R507A upon request With or without economizer Optimized R-134a version (SCA2)New high-efficiency profileNew high-efficiency profileNew high-efficiency profileNew high-efficiency profileNew high-efficiency profile Further developed geometry High rigidity Patented manufacturing process for highestprecision High tip speed to minimize blow-byDouble-walled, pressure-compensated rotorDouble-walled, pressure-compensated rotorDouble-walled, pressure-compensated rotorDouble-walled, pressure-compensated rotorDouble-walled, pressure-compensated rotorhousinghousinghousinghousinghousing Extremely stable, therefore no expansion even athigh pressure levels Additional sound attenuationProven, long-life bearings with pressure unloadingProven, long-life bearings with pressure unloadingProven, long-life bearings with pressure unloadingProven.

6 Long-life bearings with pressure unloadingProven, long-life bearings with pressure unloading Robust axial bearings in tandem configuration Bearing chamber pressure isolated by seal rings Pressure unloading of axial bearingsOptimized oil managementOptimized oil managementOptimized oil managementOptimized oil managementOptimized oil management Three-stage oil separator Long-life oil filter 10 mesh size Pressure relieved bearing chamber ensuring mini-mum refrigerant dilution in the oil and thus higherviscosityLarge volume motor for part winding or direct startLarge volume motor for part winding or direct startLarge volume motor for part winding or direct startLarge volume motor for part winding or direct startLarge volume motor for part winding or direct start- optional star delta design- optional star delta design- optional star

7 Delta design- optional star delta design- optional star delta design Especially high efficiencySemi- hermetic compact screwsSemi- hermetic compact screwsSemi- hermetic compact screwsSemi- hermetic compact screwsSemi- hermetic compact screwsSCH2/SCA2 seriesSCH2/SCA2 seriesSCH2/SCA2 seriesSCH2/SCA2 seriesSCH2/SCA2 series35 to 140 HP Nominal motor power35 to 140 HP Nominal motor power35 to 140 HP Nominal motor power35 to 140 HP Nominal motor power35 to 140 HP Nominal motor powerAE4-1322 2002 Copeland CorporationIssued 4-2002 Printed in Integrated PTC sensors in each winding coil Slot keys for maximum operating safety Stator is slide fit (field replaceable)Intelligent electronicsIntelligent electronicsIntelligent electronicsIntelligent electronicsIntelligent electronics Thermal motor temperature control by winding PTCs Phase sequence control for direction of rotation Manual reset lock-out Oil temperature protection by PTC sensorFlexible with additional coolingFlexible with additional coolingFlexible with additional coolingFlexible with additional coolingFlexible with additional cooling Direct liquid injection External oil cooler for extended application andhighest efficiencyDual capacity controlDual capacity controlDual capacity controlDual capacity controlDual capacity control Infinite or 4-step slide control with Vi operation modes by varying the controlsequence only - no need for compressor modification Simple control by

8 Solenoid coils Automatic start unloadingEconomizer with sliding suction positionEconomizer with sliding suction positionEconomizer with sliding suction positionEconomizer with sliding suction positionEconomizer with sliding suction position Unique for compact screws Efficient economizer operation with part load as well Highest cooling capacity and energy efficiency at fulland part load conditionsFully equippedFully equippedFully equippedFully equippedFully equipped Capacity control / start unloading Suction and Discharge shut-off valve Check valve in discharge gas outlet Oil sight glass Insertion type oil heater with sleeve Oil fill / drain service valve Suction gas filter with large surface are and fine mesh Electronic protection systemProven optional accessoriesProven optional accessoriesProven optional accessoriesProven optional accessoriesProven optional accessories Oil level switch Shut-off valve / adapter for economizer operation andliquid injection Adapter for external oil Compression process Compression process Compression process Compression process Compression process Viiiii-control-control-control-control-c ontrolWith Screw Compressors , suction, compression anddischarge occur in one flow direction.

9 With this processthe suction gas is pressed into the profile hollows by theprofile peaks. The volume is steadily reduced and it isthereby compressed. The compressed gas is thendischarged through a discharge port whose size andgeometry determine the so called internal volume ratio(Vi) . This value must have a defined relationship to themass flow and the working pressure ratio, to avoidlosses in efficiency due to over- and internal discharge ports of the SCH2/SCA2 screwcompressors are designed for a very wide view of high efficiency and operational safety a part ofthe discharge channel is integrated into the controlslide, which enables a Vi control at part load to this the internal volume ratio (Vi) virtually re-mains constant down to approximately 70% part economizer channel built into the control slide isanother outstanding feature (figure 3).

10 It enables a fullyfunctional operation of the subcooler circuit indepen-dently from the compressor s load conditions. This is adesign solution which is unique for Screw compressorsof this size. This ensures highest possible capacity andefficiency at both full and part load conditions. Fordetails regarding economizer operation see Section Capacity control and start Capacity control and start Capacity control and start Capacity control and start Capacity control and start unloadingSCH2/SCA2 models are provided as a standard with a Dual Capacity Control (slide system). This allows forinfinite infinite infinite infinite infinite or 4-step capacity control4-step capacity control4-step capacity control4-step capacity control4-step capacity control without compressormodifications. The different operating modes can beachieved by changing the control sequences of thesolenoid special geometry of the slide means that thevolume ratio Vi is adjusted to the operating conditions inpart-load operation.