Danfoss Scroll SZ185S4RC

8/20/2019 Danfoss Scroll SZ185S4RC

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Selection& Application Guidelines

Performer ®

scroll compressors

Single 20 to 110 kW50 - 60 Hz

R22, R407C, R134a, R404A/R507A


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PERFORMER® SCROLL COMPRESSION PRINCIPLE ...................................................................................................... 4

COMPRESSOR MODEL DESIGNATION ....................................................................................................................................................... 5Nomenclature ........................................................................................................................................................................................................................................................ 5Connection details ....................................................................................................................................................................................................................................... 5

TECHNICAL SPECIFICATIONS ......................................................................................................................................................................................... 650-Hz data ...................................................................................................................................................................................................................................................................... 660-Hz data ...................................................................................................................................................................................................................................................................... 7

OPERATING ENVELOPES ........................................................................................................................................................................................................... 8Application envelopes at dew temperatures ................................................................................................................................... 8Application envelopes at mean temperatures ..............................................................................................................................10

PIPING CONNECTIONS ................................................................................................................................................................................................................... 11Suction and discharge connections ...................................................................................................................................................................... 11Sight glass ....................................................................................................................................................................................................................................................................... 11Schrader .............................................................................................................................................................................................................................................................................. 11Oil drain ................................................................................................................................................................................................................................................................................ 11

ELECTRICAL CONNECTIONS AND WIRING ..................................................................................................................................... 12Motor voltage ......................................................................................................................................................................................................................................................... 12Electrical connections .......................................................................................................................................................................................................................... 12Suggested wiring diagrams logic ............................................................................................................................................................................. 14Danfoss MCI soft-start controller ................................................................................................................................................................................. 15

SYSTEM DESIGN RECOMMENDATIONS ................................................................................................................................................. 17Refrigerant charge limit and compressor protection ..................................................................................................... 17

Crankcase heater ................................................................................................................................................................................................................................ 17Liquid line solenoid valve (LLSV) ......................................................................................................................................................................17Pump-down cycle ............................................................................................................................................................................................................................ 17Suction accumulator ................................................................................................................................................................................................................. 17Liquid receiver ......................................................................................................................................................................................................................................... 18Protection against flooded starts and liquid floodback .............................................................................. 18Discharge gas temperature protection (DGT) ................................................................................................................... 18Refrigerant charge limits and compressor protection .................................................................................... 19

Motor protection ............................................................................................................................................................................................................................................. 20Internal motor protection .............................................................................................................................................................................................. 20

External motor protection ............................................................................................................................................................................................ 20Phase sequence and reverse rotation protection ..................................................................................................... 21Cycle rate limit ......................................................................................................................................................................................................................................... 21Voltage unbalance ......................................................................................................................................................................................................................... 22

High and low pressure protection ............................................................................................................................................................................ 22High pressure ............................................................................................................................................................................................................................................. 22Low pressure ............................................................................................................................................................................................................................................... 22Internal pressure relief valve ......................................................................................................................................................................................23

Essential piping design considerations ......................................................................................................................................................... 23

SPECIFIC APPLICATION RECOMMENDATIONS .................................................................................................................... 24Low ambient compressor operations ................................................................................................................................................................ 24

Low ambient operation and minimum pressure differential...........................................................

24Low ambient start-up .............................................................................................................................................................................................................. 24Head pressure control under low ambient conditions .................................................................................. 24Crankcase heaters ............................................................................................................................................................................................................................ 24

CONTENTS


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Low load operations ................................................................................................................................................................................................................................ 25Brazed plate heat exchangers ............................................................................................................................................................................................ 25Reversible heat pump systems ......................................................................................................................................................................................... 25

Crankcase heaters ............................................................................................................................................................................................................................ 26Discharge temperature thermostat ......................................................................................................................................................... 26Discharge line & reversing valve ...................................................................................................................................................................... 26Suction line accumulator ................................................................................................................................................................................................. 26

SOUND AND VIBRATION MANAGEMENT .......................................................................................................................................... 27Sound generation in a refrigeration / air conditioning system ................................................................. 27

Compressor sound radiation ................................................................................................................................................................................... 27Mechanical vibrations ............................................................................................................................................................................................................. 27Gas pulsation .............................................................................................................................................................................................................................................. 27

INSTALLATION ................................................................................................................................................................................................................................................... 28Compressor handling ............................................................................................................................................................................................................................ 28Mounting .......................................................................................................................................................................................................................................................................... 28Removing connections shipping plugs ........................................................................................................................................................ 29System cleanliness ....................................................................................................................................................................................................................................... 29 Tubing ..................................................................................................................................................................................................................................................................................... 29Filters driers ................................................................................................................................................................................................................................................................. 30Brazing and soldering ........................................................................................................................................................................................................................... 30

Copper to copper connections .......................................................................................................................................................................... 30Dissimilar metals connection ................................................................................................................................................................................. 30Compressor connection ..................................................................................................................................................................................................... 30

System pressure test................................................................................................................................................................................................................................

31Leak detection ....................................................................................................................................................................................................................................................... 31Vacuum pump-down and moisture removal ................................................................................................................................... 32Refrigerant charging ............................................................................................................................................................................................................................... 32Commissioning ................................................................................................................................................................................................................................................... 32Oil level checking and top-up ............................................................................................................................................................................................ 32

Oil level check ........................................................................................................................................................................................................................................... 32Oil top-up ........................................................................................................................................................................................................................................................... 32

ACCESSORIES ....................................................................................................................................................................................................................................................... 33Connectors and valves ........................................................................................................................................................................................................................ 33Lubricants ........................................................................................................................................................................................................................................................................ 33Crankcase heaters ......................................................................................................................................................................................................................................... 34

Discharge temperature protection ......................................................................................................................................................................... 35Compressor acoustic hood ....................................................................................................................................................................................................... 35

ORDERING INFORMATION AND PACKAGING ......................................................................................................................... 36Ordering information ............................................................................................................................................................................................................................ 36Packaging ........................................................................................................................................................................................................................................................................ 38

CONTENTS


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First orbit:

SUCTION

Second orbit:

COMPRESSION

Third orbit:

DISCHARGE

4

PERFORMER® SCROLL COMPRESSION PRINCIPLE

In a Danfoss Performer® scroll compres-sor, the compression is performed bytwo scroll elements located in the up-per part of the compressor above the

motor (see adjacent figure). Suctiongas enters the compressor at the suc-tion connection. The gas then flowsaround the motor and enters at thebottom side through the openings asshown. Oil droplets separate from thesuction gas and fall into the oil sump.All of the suction gas passes throughthe electrical motor, thus ensuringcomplete motor cooling in all applica-tions. After exiting the electrical mo-tor, the gas enters the scroll elements

where compression takes place.A check valve is located directly abovethe fixed scroll discharge port; thisfeature prevents the compressor fromrunning backwards once the powerhas been switched off. Ultimately, thedischarge gas leaves the compressorat the discharge connection.

The figure below illustrates the entirecompression process. The center ofthe orbiting scroll traces a circular patharound the center of the fixed scroll.

This movement creates symmetricalcompression pockets between thetwo scroll elements. Low pressure suc-tion gas is trapped within each cres-cent-shaped pocket as it gets formed;continuous motion of the orbitingscroll serves to seal the pocket, whichdecreases in volume as the pocketmoves towards the center of the scrollset increasing the gas pressure. Maxi-mum compression is achieved once apocket reaches the center where thedischarge port is located; this stageoccurs after three complete orbits.Compression is a continuous process:when one quantity of gas is beingcompressed during the second orbit,another quantity is entering the scrollsand yet another is being discharged allat the same time.


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Family, lubricant& refrigerantSM: Scroll, mineral oil,

for R22SY: Scroll, POE lubricant,

for R22SZ: Scroll, POE lubricant,

for R407C - R134a

Nominal capacity in thousand Btu/hat 60 Hz, R22,ARI conditions

UL index

VoltageMotor voltage code:3: 200-230/3/604: 380-400/3/50 - 460/3/606: 230/3/507: 500/3/50 - 575/3/609: 380/3/60

Family,lubricant

& refrigerant

Nominalcapacity

Voltage Version EvolutionIndex

Version

A9S Y A A A3 0 0

C4S Z S R1 8 5

5

MODELSM/SZ 084 - 090 - 100110 - 120 - 148 - 161

SM/SZ 115 - 125 - 160170 - 185

SY/SZ 240 - 300 SY/SZ 380

Version V R CMAMB

AAAB

AAAB

Suction and dischargeconnection

brazed rotolock brazed rotolock brazed brazed

Oil sight glass threaded threaded threaded threaded threaded threaded

Oil equalization connection 3/8’’ flare 3/8’’ flare 3/8’’ flare 1/2’’ flare 1/2’’ flare 1/2’’ flare

Oil drain connection - 1/4’’ NPT 1/4’’ NPT 1/4’’ NPT 1/4’’ NPT 1/4’’ NPT

Low pressure gauge port(schrader)

1/4’’ flare 1/4’’ flare 1/4’’ flare 1/4’’ flare 1/4’’ flare 1/4’’ flare

COMPRESSOR MODEL DESIGNATION

Performer® scroll compressors areavailable both as single compressorsand as tandem units. The examplebelow presents the single compres-

sor codification (technical reference

shown on compressor nameplate).

For tandem assemblies, please referto the Performer® Parallel Application

Guidelines documentation.

Nomenclature

Connection details

Internaloverloadprotector

V V: brazedS 084 - 090100 - 110 - 120148 - 161

Internalthermostat

C C: brazed

S 115 - 125160 - 175 - 185

R R: rotolock

Electronicprotection

module

AAABMAMB

A: brazed A: 24VA: brazed B: 115/230VM: rotolock A: 24VM: rotolock B: 115/230V

S 240* - 300*- 380*

*For trio assemblies, please contact Danfoss

Motor protectiontype

▼

Applies to

▼

Description

▼


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6

ModelNominal

Cap. 60 Hz

TR

Nominal coolingcapacity

W Btu/h

Powerinput

kW

A max

A

Effi ciency Soundpower

dB(A)

Sweptvolume

cm3

/rev

Displace-ment

m3

/h

Oilcharge

dm3

Netweight

kg

COP

W/W

E.E.R.

Btu/h /W

R 2 2 S I N G L E

SM084 7 20400 69 600 6.12 17 3.33 11.4 70 114.5 19.92 3.3 72

SM090 7.5 21800 74 400 6.54 17 3.33 11.4 70 120.5 20.97 3.3 72

SM100 8 23100 79 000 6.96 19 3.33 11.3 70 127.2 22.13 3.3 72

SM110 9 25900 88 600 7.82 20 3.32 11.3 75 144.2 25.09 3.3 80

SM115 9.5 28000 95 600 8.31 25 3.37 11.5 76 155.0 26.97 3.8 80

SM120 10 30100 102 800 8.96 29 3.36 11.5 75 166.6 28.99 3.3 80

SM125 10 30100 102 800 8.93 25 3.37 11.5 76 166.6 28.99 3.8 80

SM148 12 36100 123 100 10.80 32 3.34 11.4 79 199.0 34.60 3.6 86

SM160 13 39100 133 500 11.60 29 3.37 11.5 79.5 216.6 37.69 4.0 94

SM161 13 39000 133 200 11.59 32 3.37 11.5 79.5 216.6 37.69 3.6 86

SM175 14 42000 143 400 12.46 35 3.37 11.5 80 233.0 40.54 6.2 103

SM185 15 45500 155 300 13.62 35 3.34 11.4 80 249.9 43.48 6.2 103

SY240 20 61200 208 700 18.20 50 3.36 11.5 82 347.8 60.50 8.0 160

SY300 25 78200 267 000 22.83 69 3.43 11.7 82 437.5 76.10 8.0 160

SY380 30 92000 313 900 26.82 72 3.43 11.7 85 531.2 92.40 8.4 163

R 4 0 7 C S I N G L E

SZ084 7 19300 66 000 6.13 17 3.15 10.7 73 114.5 19.92 3.3 72

SZ090 7.5 20400 69 600 6.45 17 3.16 10.8 73 120.5 20.97 3.3 72

SZ100 8 21600 73 700 6.84 19 3.15 10.8 73 127.2 22.13 3.3 72

SZ110 9 24600 84 000 7.76 20 3.17 10.8 77 144.2 25.09 3.3 80

SZ115 9.5 26900 91 700 8.49 25 3.16 10.8 78 155.0 26.97 3.8 80

SZ120 10 28600 97 600 8.98 29 3.18 10.9 77 166.6 28.99 3.3 80

SZ125 10 28600 97 500 8.95 25 3.19 10.9 78 166.6 28.99 3.8 80

SZ148 12 35100 119 800 10.99 32 3.19 10.9 80.5 199.0 34.60 3.6 86

SZ160 13 37600 128 200 11.58 29 3.24 11.1 80.5 216.6 37.69 4.0 94

SZ161 13 37900 129 500 11.83 32 3.21 10.9 80.5 216.6 37.69 3.6 86

SZ175 14 40100 136 900 12.67 35 3.17 10.8 81 233.0 40.54 6.2 103

SZ185 15 43100 147 100 13.62 35 3.16 10.8 81 249.9 43.48 6.2 103

SZ240 20 59100 201 800 18.60 50 3.18 10.9 83.5 347.8 60.50 8.0 160

SZ300 25 72800 248 300 22.70 69 3.20 10.9 84 437.5 76.10 8.0 160

SZ380 30 89600 305 900 27.60 72 3.25 11.1 86.5 531.2 92.40 8.4 163

TECHNICAL SPECIFICATIONS

50-Hz data

Subject to modification without prior notificationFor full data details and capacity tables refer to Online Datasheet Generator : www.danfoss.com/odsg

SM/SY compressors SZ compressors

Refrigerant R22 R407C

Frequency 50 Hz 50 Hz

Standard rating conditions ARI standard conditions -

Evaporating temperature 7.2 °C 7.2 °C (dew point)

Condensing temperature 54.4 °C 54.4 °C (dew point)

Sub-cooling 8.3 K 8.3 K

Superheat 11.1 K 11.1 K

Rating conditions

TR = Ton of RefrigerationCOP = Coeffi cient Of PerformanceEER = Energy Effi ciency Ratio


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7

ModelNominal

Cap. 60 Hz

TR

Nominal coolingcapacity

W Btu/h

Powerinput

kW

A max

A

Effi ciency Soundpower

dB(A)

Sweptvolume

cm3

/rev

Displace-ment

m3

/h

Oilcharge

dm3

Netweight

kg

COP

W/W

E.E.R.

Btu/h /W

R 2 2 S I N G L E

SM084 7 24600 84 000 7.38 17 3.34 11.4 75 114.5 24.05 3.3 72

SM090 7.5 26400 90 000 7.82 17 3.37 11.5 75 120.5 25.31 3.3 72

SM100 8 27500 94 000 8.14 19 3.38 11.5 75 127.2 26.71 3.3 72

SM110 9 31600 107 800 9.35 20 3.38 11.5 78 144.2 30.28 3.3 80

SM115 9.5 33700 115 200 10.08 25 3.35 11.4 79 155.0 32.55 3.8 80

SM120 10 36700 125 300 10.80 29 3.40 11.6 78 166.6 34.99 3.3 80

SM125 10 37000 126 400 10.99 25 3.37 11.5 79 166.6 34.99 3.8 80

SM148 12 43800 149 500 13.01 32 3.37 11.5 83 199.0 41.80 3.6 86

SM160 13 47700 163 000 14.22 29 3.36 11.5 84 216.6 45.49 4.0 94

SM161 13 47600 162 600 14.07 32 3.39 11.5 84 216.6 45.49 3.6 86

SM175 14 51100 174 300 15.27 35 3.34 11.4 82.5 233.0 48.93 6.2 103

SM185 15 54300 185 400 16.22 35 3.35 11.4 82.5 249.9 52.48 6.2 103

SY240 20 74100 252 700 22.10 50 3.35 11.4 84.7 347.8 73.00 8.0 160

SY300 25 94500 322 500 27.50 69 3.43 11.7 85.9 437.5 91.90 8.0 160

SY380 30 110000 375 300 33.54 72 3.28 11.7 88.0 531.2 111.60 8.4 163

R 4 0 7 C S I N G L E

SZ084 7 22500 76 900 7.06 17 3.19 10.9 78 114.5 24.05 3.3 72

SZ090 7.5 24400 83 300 7.63 17 3.20 10.9 78 120.5 25.31 3.3 72

SZ100 8 26500 90 500 8.18 19 3.24 11.0 78 127.2 26.71 3.3 72

SZ110 9 30100 102 800 9.29 20 3.24 11.1 81 144.2 30.28 3.3 80

SZ115 9.5 32800 112 000 10.22 25 3.21 10.9 81 155.0 32.55 3.8 80

SZ120 10 34800 118 900 10.75 29 3.24 11.1 81 166.6 34.99 3.3 80

SZ125 10 34900 119 200 10.89 25 3.21 10.9 81 166.6 34.99 3.8 80

SZ148 12 42600 145 400 13.35 32 3.19 10.9 85 199.0 41.80 3.6 86

SZ160 13 45500 155 400 14.08 29 3.23 11.0 85 216.6 45.49 4.0 94

SZ161 13 46000 156 900 14.32 32 3.21 10.9 85 216.6 45.49 3.6 86

SZ175 14 48700 166 200 15.28 35 3.19 10.9 84 233.0 48.93 6.2 103

SZ185 15 51800 176 800 16.43 35 3.15 10.7 84 249.9 52.48 6.2 103

SZ240 20 71100 242 800 22.70 50 3.14 10.7 87 347.8 73.00 8.0 160

SZ300 25 87900 300 000 27.49 69 3.20 10.9 87.5 437.5 91.90 8.0 160

SZ380 30 108500 368 500 33.40 72 3.25 11.0 89.5 531.2 111.60 8.4 163

TECHNICAL SPECIFICATIONS

60-Hz data

Subject to modification without prior notificationFor full data details and capacity tables refer to Online Datasheet Generator : www.danfoss.com/odsg

SM/SY compressors SZ compressors

Refrigerant R22 R407C

Frequency 60 Hz 60 Hz

Standard rating conditions ARI standard conditions -

Evaporating temperature 7.2 °C 7.2 °C (dew point)

Condensing temperature 54.4 °C 54.4 °C (dew point)

Sub-cooling 8.3 K 8.3 K

Superheat 11.1 K 11.1 K

Rating conditions

TR = Ton of RefrigerationCOP = Coeffi cient Of PerformanceEER = Energy Effi ciency Ratio


8/40

70

65

60

55

50

45

40

35

30

-25 -20 -15 -10 -5 0 5 10 15 20

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)

Condensing temp. limits

S.H. = 30 K SUPERHEAT

S.H. = 11.1 K

75

30-20 -15 -10 -5 5 10 15 200

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


S.H. = 11.1 K

S.H. = 30 KSUPERHEAT

70

65

60

55

50

45

40

35

8

Application envelopesat dew temperatures

OPERATING ENVELOPES

The figures below show the opera-ting envelopes for SM / SY compres-sors with refrigerant R22 and for SZcompressors with refrigerants R407C,

R134a, R404A and R507A. The dischar-ge temperature depends on the com-bination of evaporating temperature,condensing temperature and suctiongas superheat. Because of this depen-dence, discharge temperature limitsare indicated by a double line. Thesolid line represents the limit shouldthe superheat be 11.1 K or less. Thedashed line, on the other hand, pro-vides the limit when the superheat is30 K. For superheat values between

11.1 K and 30 K, these two lines may

be interpolated. The operating limitsserve to define the envelope withinwhich reliable operations of the com-pressor are guaranteed:

● Maximum discharge gas tempera-ture: +135°C

● Maximum ambient temperature:+63°C (for SM / SZ 084 to 185), + 52°C(for SY / SZ 240 to 380)

● A suction superheat below 5 K is notrecommended due to the risk of li-quid floodback

● Maximum superheat of 30 K

● Minimum and maximum evapora-ting and condensing temperatures

as per the operating envelopes.

SM 084 to SM 185SY 240 to SY 380R22

SZ 084 to SZ 185R134a


9/40

75

30-20 -15 -10 -5 5 10 15 200

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


S.H. = 11.1 K


70

65

60

55

50

45

40

35

75

30

70

65

60

55

50

45

40

35

-25 -20 -15 -10 0 5 10 15-5

C o n d .

t e m p .

( ° C )


S.H. = 11.1 K


Evap. temp. (°C)

70

65

60

55

50

45

40

35

30-25 -20 -15 -10 -5 0 5 10 15 20

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


S.H. = 11.1 K

Dew temperature conditions


70

65

60

55

50

45

40

35

30-25 -20 -15 -10 -5 0 5 10 15 20

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


S.H. = 11.1 K



9

SZ 240 - 300R134a

SZ 240 to SZ 380R407Cat DEW temperature

(refer to the explanation p.10)

SZ 084 to SZ 185R407Cat DEW temperature

(refer to the explanation p.10)

SZ 084 to SZ 185

R404A / R507A

OPERATING ENVELOPES


10/40

70

65

60

55

50

45

40

35

30-25 -20 -15 -10 -5 0 5 10 15 20

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


S.H. = 11.1 K



70

65

60

55

50

45

40

35

30-25 -20 -15 -10 -5 0 5 10 15 20

C o n d .

t e m p .

( ° C )

Evap. temp. (°C)


Mean temperature conditions

S.H. = 11.1 K


pressure (log)

enthalpy

Dew

Dew

Mean

Mean

10

Application envelopes atmean temperatures

Dew temperatureandmean temperature

for R407C

OPERATING ENVELOPES

Refrigerant R407C is a zeotropic mix-ture, which causes a temperature glidein both the evaporator and condenser.When discussing evaporating and

condensing temperatures therefore, itis important to indicate whether theseare DEW point values or MEAN pointvalues. In the figure below, the dashedlines reflect constant temperature anddo not correspond with the constantpressure lines.

The following operating diagramsshow the difference between meanand dew temperature application en-velopes.

For a given cycle, the MEAN pointtemperatures are typically about 2° to3°C lower than DEW point tempera-tures. In these Selection and Applica-

tion Guidelines, Danfoss CommercialCompressors displays temperatures asDEW point values. The performance tables for R407C (seep. 6-7) are also based on DEW pointvalues.

Dew temperature

Mean temperature

Example for SZ 084 to 185

Example for SZ 084 to 185


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11

Brazed version Rotolock version

Brazed Rotolock① Adaptor➁

SM / SZ 084Suction 1’’ 1/8 - -

Discharge 3/4’’ - -

SM / SZ 090Suction 1’’ 1/8 - -


SM / SZ 100Suction 1’’ 1/8 - -


SM / SZ 110Suction 1’’ 3/8 - -


SM / SZ 115Suction 1’’ 3/8 1’’ 3/4 1’’ 1/8

Discharge 7/8’’ 1’’ 1/4 3/4’’

SM / SZ 120

Suction 1’’ 3/8 - -Discharge 7/8’’ - -

SM / SZ 125Suction 1’’ 3/8 1’’ 3/4 1’’ 1/8

Discharge 7/8’’ 1’’ 1/4 3/4’’

SM / SZ 148Suction 1’’ 3/8 - -


SM / SZ 161Suction 1’’ 3/8 - -


SM / SZ 160Suction 1’’ 5/8 2’’ 1/4 1’’ 3/8

Discharge 1’’ 1/8 1’’ 3/4 7/8’’

SM / SZ 175Suction 1’’ 5/8 2’’ 1/4 1’’ 3/8

Discharge 1’’ 1/8 1’’ 3/4 7/8’’

SM / SZ 185Suction 1’’ 5/8 2’’ 1/4 1’’ 3/8

Discharge 1’’ 1/8 1’’ 3/4 7/8’’

SY / SZ 240Suction 1’’ 5/8 2’’ 1/4 1’’ 5/8

Discharge 1’’ 1/8 1’’ 3/4 1’’ 1/8

SY / SZ 300Suction 1’’ 5/8 2’’ 1/4 1’’ 5/8

Discharge 1’’ 1/8 1’’ 3/4 1’’ 1/8

SY / SZ 380Suction 2’’ 1/8 - -

Discharge 1’’ 3/8 - -

Suction anddischarge connections

PIPING CONNECTIONS

① ➁

Oil fillconnectionandgauge port

Oil drainconnection

Oil drain

Sight glass

The oil drain connection allows oil tobe removed from the sump for chan-ging, testing, etc. The fitting containsan extension tube into the oil sump tomore effectively remove the oil. Theconnection is composed of a female1/4" NPT fitting.

Note :

On SY / SZ 240-380, it is not possible todrain oil from the suction connection.

Schrader

All Performer® scroll compressors comeequipped with a sight glass which maybe used to determine the amount andcondition of the oil contained withinthe sump.

The oil fill connection and gauge portis a 1/4" male flare connector incorpo-rating a Schrader valve.


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12

Terminal box wiring forSM / SZ 084 - 090 - 100 -110 - 120 - 148 - 161*compressors* Except for motor voltage code 3

Terminal box wiring forSM / SZ 115 - 125 - 160 -161 (motor code 3) -175 - 185

ELECTRICAL CONNECTIONS AND WIRING

Motor voltage Performer® scroll compressors areavailable in five different motor vol-tages. Motor voltage code 3 and 9 for

60 Hz, motor code 6 for 50 Hz andmotor code 4 and 7 for both 50 and60 Hz.

Motor voltagecode 3

Motor voltagecode 4with thermostat

protector andinternal overload

(S 084 - S 185)

Motor voltagecode 4

with PTC andelectronic module

(S 240 - S 380)Motor voltage

code 6Motor voltage

code 7Motor voltage

code 9

Nominal voltage50 Hz - 380-400V - 3 - 50 Hz 400V - 3 - 60 Hz 230V - 3 - 50 Hz 500V - 3 - 50Hz -

Voltage range50 Hz

- 340-440V 360 - 440 V 207 - 253V 450 - 550V -

Nominal voltage60 Hz 200-230V - 3 - 60 Hz 460V - 3 - 60 Hz 460V - 3 - 60Hz - 575V - 3 - 60 Hz 380 - 3 - 60 Hz

Voltage range60Hz 180 - 253 V 414 - 506V 414 - 506V - 517 - 632V 342 - 418 V

Electrical connections Electrical power is connected to thecompressor terminals by Ø 4.8 mm(3/16”) screws. The maximum tighte-

ning torque is 3 Nm. Use a 1/4’’ ringterminal on the power leads.

• The terminal box is provided with aØ 29 mm hole for the power supplyand a Ø 29 mm knockout.

• The protection rating of the terminalbox is IP54 when correctly sized IP54-rated cable glands are used.

IP ratings according to IEC 529

Terminal box

Power supply

The terminal box is provided with2 double knockouts for the power

supply and 3 knockouts for the safetycontrol circuit.

ø 29 mm knockout

Coverholdingscrew (x2)

Torque:2.2 N.m.

Discharge gas thermostat kit

(optional)

Discharge gas pipe

Belt typecranckaseheater(optional)

1/4” spadeconnector

Safety control circuitmotor thermostat

Terminal box

Power supply


13/40

L N S1 S2 M1 M2

L1 L2 L3Bl ac k B lu e B ro wn

The 2 power supply, double knockoutsaccommodate the following diameters:Ø 44 mm / Ø 1”3/4 hole (for a 1”1/4

conduit) and Ø 34mm / Ø 1”3/8

hole (for a 1” conduit),Ø 32.1 mm / Ø 1.26” hole andØ 25.4 mm / Ø 1” hole.

The 3 other knockouts are as follows:Ø 20.5 mm / Ø 0.81”Ø 22 mm / Ø 7/8” (for a 1/2” conduit)Ø 16.5 mm / Ø 0.65”

The protection rating of the terminalbox is IP54 when correctly sized IP54rated cable glands are used.

Connect the internal safety thermostatwith 1/4” female spade connectors.

13

Terminal box wiring forSY / SZ 240 – 300 – 380


Electronic protection

module wiring

The terminal box is provided with 4double knockouts for the power sup-ply and 4 knockouts for the safetycontrol circuit. The 4 power supplydouble knockouts accommodate thefollowing diameters:

Ø 22 mm / Ø 7/8” holeand Ø 16.5 mm / Ø 0.65” knockout

Ø 22 mm / Ø 7/8” holeand Ø 16.5 mm / 0.65” knockout

Ø 43.7 mm / Ø 1”23/32 holeand Ø 34.5 mm / 1”23/64 knockout

Ø 40.5 mm / Ø 1.59” holeand Ø 32.2 mm / 1.27” knockout

The 4 others knockouts are as follows:Ø 20.5 mm / Ø 0.81”Ø 20.5 mm / Ø 0.81”Ø 50 mm / Ø 1” 31/32Ø 25.2 mm / Ø 0.99”

The protection rating of the terminalbox is IP54 when correctly sized IP54-rated cable glands are used.

IP ratings according to IEC 529.

The motor protection module comespreinstalled within the terminal boxand is accompanied with both phasesequence protection and pre-wiredthermistor connections. The modulemust be connected to a power supply

of the appropriate voltage. The mo-dule terminals are 6.3 mm size Fastontype.

Discharge gas thermostat kit (optional) Discharge gas pipe

Belt typecranckaseheater

Cover holding screws (x4)

Torque: 2.2 N.m.

Power supply

M1, M2Control circuit

Power supply

Black Blue

Brown

Phase sequence input

Internal control contact

Safetycircuit

Thermistorconnection

Module power24 or 115/230 vac


14/40

T T

THTH

KA

A1 A2 A3A1160 s

A2 KA

~

~

M

DGT

HP180 s

THBP

CONTROL CIRCUIT

F1F1

KM

KM

KM

KA KA

A1

A2

A3

KA

KA

KS

KS

KS

L1 L3 L2

Q1

F2

T1

T3

T2

LLSV KS

Suggested wiringdiagrams logicCompressor models SM / SZ 084 – 090 – 100 – 110 – 120 – 148 - 161

Wiring diagram with pump-down cycle

KM

L1 L3 L2

Q1

F2

CONTROL CIRCUIT

F1F1

KM KA

KA KS

KS

KS

BP

HP

DGT

TH

180 s

85 52 019 - A

T1 T2

M

T3

KA KA

A1

A2

A3

Wiring diagram without pump-down cycle

CONTROL CIRCUIT

F1F1

KA KAKA

HP

T1 T2

T3

KM

DGT

KS

KS

1 2

M

KS

KS

BP

KAKM

KM

LLSV

180s

TH

F2

Q1

L1 L3 L2

A1

A2

A3

Suggested wiringdiagrams logicCompressor models SM / SZ 115 – 125 – 160 – 175 – 185


CONTROL CIRCUIT

F1 F1

KA KAKA

HP

T1 T2

T3

KM

DGT

KS

KS

1 2THKS

BP

KAKM

180s

F2

Q1

L 1 L 3 L 2

M

A1

A2

A3


14


Short cycle timer fonction


15/40

15

Danfoss MCIsoft-start controller


Legends

Compressor modelSoft start referenceambient max. 40°C

Soft start referenceambient max. 55°C

SM / SZ 084

MCI 15C

MCI 15CSM / SZ 090

SM / SZ 100MCI 25C

SM / SZ 110

SM / SZ 115 -125

MCI 25C MCI 25C*SM / SZ 120

SM / SZ 160 - 161 - 148

SM / SZ 175 - 185SY / SZ 240 - 300 MCI 50C*

SY / SZ 380 Contact Danfoss* By-pass contactor (K1) required.See application example p.16

The inrush current for the Performer®scroll compressors with motor code4 (400V / 3 / 50Hz or 460V / 3 / 60Hz)can be reduced using the Danfoss di-gitally-controlled MCI compressor softstarter. MCI soft starters are designedto reduce the starting and stoppingcurrent of 3-phase AC motors; MCI softstarters can reduce the in-rush current

by up to 40%, thereby eliminating the

detrimental effects of high starting tor-que surges and costly demand char-ges from the resultant current spike.Upon starting, the controller graduallyincreases the voltage supplied to themotor until full-line voltage has beenreached. All settings, such as ramp-uptime and initial torque, are preset atthe factory and do not require modi-

fication.

Suggested wiringdiagrams logicCompressor models SY / SZ 240 - 300 - 380

A1

A3

A2


A1

A3

A2


Control device ...................................................TH Optional short cycle timer (3 min) ......... 180 sControl relay .....................................................KALiquid Line Solenoid valve .........................LLSV Compressor contactor ................................... KMSafety lock out relay ........................................ KS

Pump-down control & L.P. switch ................ BP H.P. safety switch .............................................HP

Fused disconnect .............................................Q1Fuses ....................................................................F1External overload protection .........................F2Compressor motor ........................................... MMotor safety thermostat ............................. thMDischarge gas thermostat ..........................DGT

Motor Protection Module ......................... MPMThermistor chain ................................................S


16/40

16

MCI with

bypass contactor

Input controlled

soft start

By means of the built-in auxiliary con-tact (23-24) the bypass function is easilyachieved, see wiring diagram below.

No heat is generated from the MCI.As the contactor always switches in

no-load condition it can be selectedon the basis of the thermal current(AC-1).

(13-14 contact not applicable withMCI 25C)


When the control voltage is applied to

A1 - A2, the MCI soft starter will startthe motor, according to the settingsof the ramp-up time and initial torque

adjustments. When the control voltage

is switched OFF, the motor will switchoff instantaneously.


17/40

17

SYSTEM DESIGN RECOMMENDATIONS

Refrigerant charge limitand compressorprotection

Performer® scroll compressors incor-porate internal safety devices such asmotor temperature protection, rever-se rotation protection and a dischar-

ge gas check valve. Additional safetydevices or system components may

however be required to ensure ade-quate protection of the compressor.Depending on the system configura-tion and application, one or several

of the following methods should beconsidered.

Crankcase heater When the compressor is idle, the oiltemperature in the sump of the com-pressor must be maintained at nolower than 10 K above the saturationtemperature of the refrigerant on thelow-pressure side. This requirementensures that the liquid refrigerant isnot accumulating in the sump. A crank-

case heater is only effective if capableof sustaining this level of temperaturedifference. Tests must be conducted toensure that the appropriate oil tempe-rature is maintained under all ambientconditions (temperature and wind).However, below –5°C ambient tem-perature and a wind speed of above5 m/sec, we recommend that theheaters be thermally insulated in orderto limit the surrounding energy losses.Since the total system charge maybe undefined, a crankcase heater is

recommended on all stand-alone com-pressors and split systems. In addition,any system containing a refrigerantcharge in excess of the maximum re-commended system charge for com-pressors requires a crankcase heater. Acrankcase heater is also required on allreversible cycle applications.

Notes: Belt-type crankcase heater accessoriesare available from Danfoss (see page34). The heater must be energized fora minimum of 12 hours before initialstart-up (compressor service valvesopened) and must remain energizedwhenever the compressor is off.Provide separate electrical supply forthe heaters so that they remain ener-gized even when the machine is out ofservice (eg. seasonal shutdown).

Liquid line solenoid valve

(LLSV)

An LLSV may be used to isolate theliquid charge on the condenser side,thereby preventing against chargetransfer or excessive migration to thecompressor during off-cycles.

The quantity of refrigerant on the low-pressure side of the system can be fur-ther reduced by using a pump-downcycle in association with the LLSV.

Pump-down cycle

Suction accumulator

A pump-down cycle represents oneof the most effective ways to protectagainst the off-cycle migration of li-

quid refrigerant. Once the controls hasbeen satisfied, a solenoid valve closeson the condenser outlet. The compres-sor then pumps the majority of the sys-tem charge into the condenser and re-ceiver before the system stops on the

low pressure pump-down switch. Thisstep reduces the amount of charge onthe low side in order to prevent off-

cycle migration. Recommended set-tings of the low-pressure pump-downswitch can be found in the table onp. 22. For suggested wiring diagrams,please see p. 14-15.

A suction accumulator offers protec-tion against refrigerant floodback atstart-up, during operations or afterdefrosting (heat pump). Sustained

and repeated liquid slugging andfloodback can seriously impair theoil’s ability to lubricate. The suctionline accumulator also protects against

off-cycle migration by providing addi-tional internal free volume to the lowside of the system. The accumulatorshould not be sized for less than 50%

of the total system charge. Tests mustbe conducted to determine the actualrefrigerant holding capacity neededfor the application.


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18

DGT protection is required if the highand low pressure switch settings do notprotect the compressor against opera-tions beyond its specific applicationenvelope. Please refer to the examplesbelow, which illustrates where DGTprotection is required (Example 1) andwhere it is not (Example 2).

Example 1 (R22, SH = 11 K)LP switch setting:LP1 = 1.8 bar (g) (-17°C)HP switch setting:

HP1 = 25 bar (g) (62°C)Risk of operation beyond the applica-tion envelope.DGT protection required.

Example 2 (R22, SH = 11 K)LP switch setting:LP2 = 2.9 bar (g) (-7°C)HP switch setting:HP2 = 21 bar (g) (55°C)No risk of operation beyond the appli-cation envelope.No DGT protection required.

Flooded starts occur when a compres-sor starts up with a large quantity of

liquid refrigerant in the compressor.Liquid finds its way into a compressorby means of off-cycle migration. Liquidfloodback occurs when liquid refrige-rant returns to a compressor while it isrunning. Excessive liquid refrigerant inthe compressor will cause oil dilution,liquid washout of oil from the bearings,or loss of oil from the sump. The cran-kcase heater will not be effective if thesystem design allows for uncontrolledfloodback to the compressor duringrunning or starting. Performer® scroll

compressors can tolerate occasionalflooded starts as long as the systemcharge does not exceed that given inthe table in the following section. Per-former® scrolls can also handle inter-mittent floodback, yet system designmust be such that repeated and exces-sive floodback is not possible.

Off-cycle refrigerant migration occurswhen the compressor is located at thecoldest part of the installation, whenthe system uses a bleed-type expan-sion device, or if liquid can migrate

from the evaporator into the compres-sor sump by gravity. If the system char-

ge exceeds the limit shown in the ta-ble, a crankcase heater must be used.

During operations, liquid floodbackmay be detected by measuring eitherthe oil sump temperature, whichshould be at least 10 K above the satu-rated suction temperature, or the dis-charge gas temperature, which shouldbe at least 30 K above the saturateddischarge temperature. If at any timeduring operations, the oil sump tem-perature drops to within 10 K or less

above the saturated suction tempera-ture, or should the discharge gas tem-perature be less than 30 K above thesaturated discharge temperature, thelubricant will become excessively dilu-ted and tests would have to be perfor-med in order to select an appropriatecompressor protection method. Repe-titive liquid floodback testing must becarried out under TXV threshold ope-rating conditions: a high pressure ratioand minimum load, along with themeasurement of both suction super-heat and discharge gas temperature.

Liquid receiver

Protection against flooded

starts and liquid floodback

A liquid receiver is highly recommen-ded on split systems and remote con-denser systems with a total refrigerantcharge in excess of the recommended

maximum for the compressor. Becau-se of the long refrigerant lines thesesystems have a relatively high systemcharge which is hard to define with ac-curacy. Further these types of systemsquite often tend to be overcharged inthe field. By installing a liquid receiver,a pump-down cycle can then be intro-

duced in order to safely store the re-frigerant charge during the off-cycles,which greatly reduces the chance ofrefrigerant migration back to the com-

pressor.On unitary or close-coupled systems,where the system refrigerant charge isexpected to be both correct and defi-nable the entire system charge may bestored in the condenser during pump-down if all components have beenproperly sized.

Discharge gas temperature

protection (DGT)



19/40

70

65

60

55

50

45

40

35

30

-25 -20 -15 -10 -5 0 5 10 15 20

C o n d . t e m p .

( ° C )

Evap. temp. (°C)

LP1 LP2

HP2

HP1

R22

D G T

- l i m i

t

Example 1

Example 2

REC REQ

19


A discharge temperature protectiondevice must be installed on all heatpumps. In reversible air-to-air and air-to-water heat pumps the discharge

temperature must be monitored du-ring development test by the equip-ment manufacturer.

The DGT should be set to open at a dis-charge gas temperature of 135°C.

Refrigerant charge limits

and compressor protection

Compressor modelsS 084S 090S 100

S 110S 120

S 115S 125

S 148S 160S 161

S 175S 185

S 240S 300S 380

Refrigerant charge limit (kg) 8.5 10 11 12.5 13.5 16 20

Notes: The compressor mustnot be allowed to cycle on the

discharge gas thermostat. Continuousoperations beyond the compressor’s

operating range will cause serious da-mage to the compressor!

A DGT accessory is available from Dan-foss Commercial Compressors: refer topage 35.

The refrigerant charge limits listed inthe table below will help evaluate therequired compressor protection in re-lation with the system charge and theapplication.

Notes:

For reversible heat pump systems andother specific applications, please re-fer to section "Specific Application Re-commendations".

BELOW charge limit ABOVE charge limit

Cooling only systems,

Packaged unitsNo test or additional safeties required

Refrigerant migration & floodback test

Crankcase heater

Cooling only systems

with remote condensor

and split system units


Crankcase heater, because full system

charge is not definable (risk of overcharging)


Crankcase heater

Liquid receiver

Reversible heat pump system

Specific tests for repetitive floodback

Crankcase heater

Discharge gas thermostat

Recommended RequiredNo test or additional safeties required

REQ

REQ

REC

REQ

REQ

REQ

REC

REC

REQ

REQ

The above chart represents basicguidelines for reliable compressoroperations and safety. Please contact

Danfoss technical support for anydeviations from these guidelines.


20/40

20

Motor protection

Internal motor protection

Compressor modelOverheating

protectionOvercurrentprotection

Locked rotorprotection

Single-phasingprotection

SM / SZ 084 - 090 - 100 -110 - 120 - 148 - 161

Internal Internal Internal Internal

SM / SZ 115 - 125 - 160- 175 - 185

Internal Compulsory external overload protector

SY / SZ 240 - 300 - 380 Internal Internal Internal Internal

Compressor models SM / SZ 084

- 090 - 100 - 110 - 120 - 148 - 161 have been provided with an internaloverload motor protection to preventagainst excessive current and tempe-rature caused by overloading, low re-frigerant flow phase loss or incorrectmotor rotation. The cutout current isthe MCC value listed in the data sheets.While not compulsory, an additionalexternal overload protection is still ad-visable for either alarm or manual re-set. The protector is located in the starpoint of the motor and, should it beactivated, will cut out all three phases.It will be reset automatically.

Compressor models SM / SZ 115 -

125 - 160 - 175 - 185 have been pro-vided with a bimetallic single-pole,single-throw thermostat located inthe motor windings. In the event ofmotor overheating caused by lowrefrigerant flow or improper motorrotation, the thermostat will open. Be-cause the thermostat is an automatic

reset device, it must be wired within alockout safety circuit with a manual re-set to restart the unit. For overcurrentand phase loss protection, an exter-nal overload protector must be usedfor the SM / SZ 115, 125, 160, 175 and

185 models. The table below shows

the protection method for the variouscompressor models.

Compressor models SY / SZ 240 - 300

- 380 are delivered with a preinstalledmotor protection module inside theterminal box. This device provides foreffi cient and reliable protection againstoverheating and overloading as well asphase loss/reversal.The motor protec-tor comprises a control module andPTC sensors embedded in the motorwinding. The close contact between

thermistors and windings ensures avery low level of thermal inertia.Themotor temperature is being constantlymeasured by a (PTC) thermistor loopconnected on S1-S2.If any thermistor exceeds its responsetemperature, its resistance increasesabove the trip level (4,500 Ω) and theoutput relay then trips (i.e. contactsM1-M2 are open). After cooling tobelow the response temperature (re-sistance < 2,750 Ω), a 5 minute time

delay is activated. After this delay haselapsed, the relay is once again pulledin (i.e. contacts M1-M2 closed). Thetime delay may be cancelled by meansof resetting the mains (L-N disconnect)for approx. 5 sec.


External motor protection All safety devices must comply with therequirements of the pertinent certifi-cation authorities in the country wherethe compressor will be used. The exter-nal overload protector can be either athermal overload relay or a circuit brea-ker. A thermal overload relay shouldbe set to trip at not more than 140%of the compressor-rated load current.

A circuit breaker, on the other hand,should be set at not more than 125%of the compressor rated load current. The rated load current is the maximumcurrent expected during operationsof the considered application; it canbe found either in the correspondingdata sheets or in the Danfoss Commer-cial Compressors selection program


21/40

CompressorStart

Phase monitoring

Phase sequence module logic

21


Phase sequence and reverse

rotation protection

for all compressors. The tripping cur-rent must never exceed the MMT va-lue found in the data sheets; the MMTvalue appears as "A.Max" on the com-

pressor nameplate.Further requirements for the externaloverload protector are:● Overcurrent protection: The protector must trip within 2 minu-

tes at 110% of the Maximum Must-Tripcurrent.● Locked rotor protection: The protector must trip within 10 se-

conds upon starting at a locked rotorcurrent.● Single-phasing protection: The protector must trip when one ofthe three phases fails.

Cycle rate limit The system must be designed in a waythat guarantees a minimum compres-sor running time of 2 minutes so as toprovide for suffi cient motor coolingafter start-up along with proper oil re-turn. Note that the oil return may varysince it depends upon system design. There must be no more than 12 startsper hour (6 when a resistor soft-start

accessory is introduced); a numberhigher than 12 reduces the servicelife of the motor-compressor unit. Ifnecessary, place an anti-short-cycletimer in the control circuit, connectedas shown in the wiring diagram (p14-15). A three-minute (180-sec) time outis recommended.

Use a phase meter to establish thephase orders and connect line phasesL1, L2 and L3 to terminals T1, T2 and T3, respectively. The compressor willonly operate properly in a single direc-

tion, and the motor is wound so that ifthe connections are correct, the rota-tion will also be correct.

Compressor models SM / SZ 084 to

185 incorporate an internal reversevent valve which will react in the pre-sence of reverse rotation and will al-lows refrigerant to circulate througha by-pass from the suction to the dis-charge. Although reverse rotation isnot destructive, even over long periodsof time up to several days it should be

corrected as soon as possible. Reverserotation will be obvious to the user assoon as power is turned on; the com-pressor will not build up any pressure,the sound level will be abnormallyhigh and power consumption will beminimal. If reverse rotation symptoms

occur, shut the compressor down andconnect the phases to their proper ter-minals. If reverse rotation is not halted,the compressor will cycle off on the in-ternal motor protection.

Compressor models SY / SZ 240 to380 are delivered with an electronicmodule which provides protectionagainst phase reversal and loss atstart-up. Apply the recommendedwiring diagrams from page 15. Thecircuit should be thoroughly checkedin order to determine the cause of thephase problem before re-energizingthe control circuit. The phase sequencing and phase lossmonitoring functions are active during

a 5 sec. window 1 sec. after compressorstart-up (power on L1-L2-L3). Shouldone of these parameters be incorrect,the relay would lock out (contact M1-M2 open). The lockout may be cancel-led by resetting the power mains (dis-connect L-N) for approximately 5 sec.


22/40

Vavg = Mean voltage of phases 1, 2, 3.V1-2 = Voltage between phases 1 & 2.

V1-3 = Voltage between phases 1 & 3.V2-3 = Voltage between phases 2 & 3.

| Vavg - V1-2 | + | Vavg - V1-3 | + | Vavg - V2-3 |

2 x Vavg

% voltageunbalance

= x 100

22

connected to the service valve gaugeport, which must not be isolated.

Note:

Because power consumption of scrollcompressors is almost directly pro-portional to discharge pressure, thehigh-pressure control can be used toindirectly limit the maximum current

draw. A high-pressure control used inthis manner however can never repla-ce an external overload protector.

High and lowpressure protection

High pressure A high-pressure (HP) safety switch isrequired to shut down the compressorshould the discharge pressure exceedthe values shown in the table below. The high-pressure switch can be setto lower values depending on theapplication and ambient conditions. The HP switch must either be placed ina lockout circuit or consist of a manual

reset device to prevent cycling aroundthe high-pressure limit. If a dischargevalve is used, the HP switch must be

R22 R407C R134a R404A/R507A

Working pressure range high side bar (g) 10.9 - 27.7 10.5 - 29.1 6.7 - 20.2 12.7 - 32

Working pressure range low side bar (g) 1.4 - 6.9 1.1 - 6.4 0.6 - 3.9 2 - 7.3

Maximum high pressure safety switch setting bar (g) 28 29.5 20.5 32.5

Minimum low pressure safety switch setting * bar (g) 0.5 0.5 0.5 0.5

Minimum low pressure pump-down switch setting ** bar (g) 1.3 1.0 0.5 1.8


Low pressure A low pressure (LP) safety switch mustbe used. Deep vacuum operations ofa scroll compressor can cause internalelectrical arcing and scroll instability.Performer® scroll compressors exhibithigh volumetric effi ciency and maydraw very low vacuum levels, whichcould induce such a problem. Theminimum low-pressure safety switch(loss of charge safety switch) setting

is given in the following table. Forsystems without pump-down, the LPsafety switch must either be a manuallockout device or an automatic switchwired into an electrical lockout circuit. The LP switch tolerance must not al-low for vacuum operations of the com-pressor. LP switch settings for pump-down cycles with automatic reset arealso listed in the table below:

*LP safety switch shall never be bypassed.**Recommended pump-down switch settings: 1.5 bar (R22, R407C, R404A) or

1 bar (R134a) below nominal evaporating pressure.

The operating voltage limits are shownin the table on page 12.The voltageapplied to the motor terminals mustlie within these table limits during

both start-up and normal operations. The maximum allowable voltage

Voltage unbalance unbalance is 2%. Voltage unbalancecauses high amperage over one orseveral phases, which in turn leads tooverheating and possible motor da-

mage. Voltage unbalance is given bythe formula:


23/40

HP

>4 m/s

0.5%

max. 4 m

max. 4 m

0.5%

U-trap

>4m/s

Evaporator

LP

8 to 12 m/s

HP

LP

Condenser

23

Essential piping designconsiderations

Proper piping practices should be em-ployed to ensure adequate oil return,

even under minimum load conditionswith special consideration given to thesize and slope of the tubing comingfrom the evaporator. Tubing returnsfrom the evaporator should be desi-gned so as not to trap oil and to pre-vent oil and refrigerant migration backto the compressor during off-cycles.

If the evaporator lies above the com-pressor, as is often the case in split orremote condenser systems, the addi-tion of a pump-down cycle is stron-

gly recommended. If a pump-downcycle were to be omitted, the suctionline must have a loop at the evapora-tor outlet to prevent refrigerant fromdraining into the compressor duringoff-cycles.

If the evaporator were situated belowthe compressor, the suction riser mustbe trapped so as to prevent liquid re-frigerant from collecting at the ther-mal bulb location (see fig. 1).

When the condenser is mounted at a

higher position than the compressor, asuitably sized «U»-shaped trap close to

the compressor is necessary to preventoil leaving the compressor from drai-ning back to the discharge side of thecompressor during off cycle. The up-per loop also helps avoid condensedliquid refrigerant from draining backto the compressor when stopped (seefig. 2).

Piping should be designed with ade-quate three-dimensional flexibility. Itshould not be in contact with the sur-rounding structure, unless a propertubing mount has been installed. This

protection proves necessary to avoidexcess vibration, which can ultimatelyresult in connection or tube failuredue to fatigue or wear from abrasion.Aside from tubing and connection da-mage, excess vibration may be trans-mitted to the surrounding structureand generate an unacceptable noiselevel within that structure as well (formore information on noise and vibra-tion, see the section on: "Sound andvibration management" p.27).


fig 1 fig 2

Internal pressure

relief valve

The SY / SZ 240 to SY / SZ 380 incorpo-rate an internal relief valve set to openbetween the internal high and lowpressure sides of the compressor when

the pressure differential between thedischarge and suction pressures sur-passes 31 to 38 bar. This safety feature prevents the com-pressor from developing dangerouslyhigh pressures should the high pres-sure cutout, for whatever reason, failto shut down the compressor.

HP

LP Relief valve


24/40

24

Low ambient start-up Under cold ambient conditions (


25/40

25

SPECIFIC APPLICATION RECOMMENDATIONS

Low load operations It is recommended that the unit betested and monitored at minimumload and, if possible, during low am-bient conditions as well. During con-

ditions of low load on the system, thefollowing considerations should betaken into account to ensure propersystem operating characteristics.● The superheat setting of the expan-sion device should be suffi cient to en-sure proper superheat levels duringlow loading periods. A minimum of5 K stable superheat is required. In ad-dition, the refrigerant charge shouldbe suffi cient to ensure proper sub-cooling within the condenser so as toavoid the risk of flashing in the liquid

line before the expansion device. Theexpansion device should be sized toensure proper control of the refrige-rant flow into the evaporator. An over-sized valve may result in erratic con-

trol. This consideration is especiallyimportant in manifolded units wherelow load conditions may require thefrequent cycling of compressors. This

can lead to liquid refrigerant enteringthe compressor if the expansion valvedoes not provide stable refrigerant su-perheat control under varying loads.● Condenser fans should be cycled insuch a way that the minimum pressu-re differential is maintained betweenthe suction and discharge pressures.Variable-speed fans can also be usedto control the amount of heat to be re-moved from the condenser.● The compressors should be run fora minimum period in order to ensure

that the oil has suffi cient time to pro-perly return to the compressor sumpsand that the motor has suffi cient timeto cool under conditions of lowest re-frigerant mass flows.

Brazed plateheat exchangers

Brazed plate heat exchange needsvery little internal volume to satisfythe set of heat transfer requirements.Consequently, the heat exchanger of-fers very little internal volume for thecompressor to draw vapor from on the

suction side. The compressor can thenquickly enter into a vacuum condition;it is therefore important that the ex-pansion device be sized correctly andthat a suffi cient pressure differentialacross the expansion device be availa-ble to ensure adequate refrigerantfeed into the evaporator. This aspectis of special concern when operatingthe unit under low ambient and loadconditions. For further information onthese conditions, please refer to the

previous sections.Due to the small volume of the brazed

plate heat exchanger, no pump-downcycle is normally required. The suctionline running from the heat exchangerto the compressor must be trappedto avoid refrigerant migration to thecompressor.

When using a brazed plate heat ex-changer as the condensing coil, a suffi -cient free volume for the discharge gasto accumulate is required in order toavoid excess pressure buildup. At least1 meter of discharge line is necessaryto generate this volume. To help re-duce the gas volume immediately af-ter start-up even further, the supply ofcooling water to the heat exchangermay be opened before the compres-sor starts up so as to remove superheat

and condense the incoming dischargegas more quickly.

Reversible heat pumpsystems

Transients are likely to occur in rever-sible heat pump systems, i.e. a chan-geover cycle from cooling to heating,defrost or low-load short cycles. Thesetransient modes of operation maylead to liquid refrigerant carryover(or floodback) or excessively wet re-frigerant return conditions. As such,reversible cycle applications require

specific precautions for ensuring along compressor life and satisfactoryoperating characteristics. Regardlessof the refrigerant charge in the system,

specific tests for repetitive floodbackare required to confirm whether ornot a suction accumulator needs to beinstalled. A crankcase heater and dis-charge gas thermostat are required forreversible heat pump applications. The following considerations coverthe most important issues in the realmof common applications. Each appli-

cation design however should be tho-roughly tested to ensure acceptableoperating characteristics.


26/40

26

Crankcase heaters Crankcase heaters are mandatory onreversible cycle applications given thehigh probability of liquid migrationback to the compressor sump during

off-cycles due to the outdoor locationof most units and operations duringlow ambient conditions.

Discharge temperature

thermostat

Heat pumps frequently utilize highcondensing temperatures in order toachieve a suffi cient temperature risein the medium being heated. At thesame time, they often require low eva-porator pressures to obtain suffi cienttemperature differentials between theevaporator and the outside tempera-ture. This situation may result in high

discharge temperature; as such, it ismandatory that a discharge gas ther-mostat be installed on the discharge

line to protect the compressor fromexcessive temperatures. Operatingthe compressor at too high dischargetemperatures can result in mechanicaldamage to the compressor as well asthermal degradation of the compres-sor lubricating oil and a lack of suffi -cient lubrication. The discharge gas thermostat should

be set to shut down the compressorin the event discharge gas rises above135°C.

Discharge line

and reversing valve

The Performer® scroll compressor isa high volumetric machine and, assuch, can rapidly build up pressurein the discharge line if gas in the linebecomes obstructed even for a veryshort period of time which situation

may occur with slow-acting, reversingvalves in heat pumps. Discharge pres-sures exceeding the operating envelopemay result in nuissance high pressureswitch cutouts and place excess strainon both the bearings and motor. To prevent such occurrences, it isimportant that a 1 meter minimumdischarge line length be allowedbetween the compressor discharge

port and the reversing valve or anyother restriction. This gives suffi cientfree volume for the discharge gas tocollect and to reduce the pressurepeak during the time it takes for thevalve to change position. At the same

time, it is important that the selectionand sizing of the reversing or 4 wayvalve ensure that the valve switchesquickly enough to prevent against toohigh discharge pressure and nuisancehigh pressure cutouts.Check with the valve manufacturerfor optimal sizing and recommendedmounting positions.

The use of a suction line accumulatoris strongly recommended in reversi-ble-cycle applications as a result of thepossibility of a substantial quantityof liquid refrigerant remaining in theevaporator, which acts as a condenserduring the heating cycle. This liquid refrigerant can then returnto the compressor, either flooding thesump with refrigerant or as a dynamicliquid slug when the cycle switches

back to a defrost cycle or to normalcooling operations.Sustained and repeated liquid sluggingand floodback can seriously impair theoil’s ability to lubricate the compressorbearings.This situation can be obser-ved in wet climates where it is neces-sary to frequently defrost the outdoorcoil in an air source heat pump. In suchcases a suction accumulator becomesmandatory.

Suction line accumulator

SPECIFIC APPLICATION RECOMMENDATIONS


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Sound generationin a refrigeration /air conditioning system

Typical sound and vibration inRefrigeration and Air-Conditioningsystems encountered by design andservice engineers may be broken

down into the following three sourcecategories.Sound radiation:

This generally takes an airborne path.Mechanical vibrations:

These generally extend along the parts

of the unit and structure.Gas pulsation:

This tends to travel through the coo-ling medium, i.e. the refrigerant.

The following sections will focus onthe causes and methods of mitigationfor each of the above sources.

SOUND AND VIBRATION MANAGEMENT

Compressor sound

radiation

For sound radiating from the compres-sor, the emission path is airborne andthe sound waves are traveling directlyfrom the machine in all directions. The Performer® scroll compressor isdesigned to be quiet and the frequen-cy of the sound generated is pushedinto the higher ranges, which not onlyare easier to reduce but also do notgenerate the penetrating power oflower-frequency sound.Use of sound-insulation materials onthe inside of unit panels is an effec-tive means of substantially reducingthe sound being transmitted to theoutside. Ensure that no components

capable of transmitting sound/vibra-tion within the unit come into directcontact with any non-insulated partson the walls of the unit.Because of the Performer’s unique de-sign of a full-suction gas-cooled mo-tor, compressor body insulation acrossits entire operating range is possible.Accoustic hoods are available fromDanfoss Commercial Compressors asaccessories. These hoods are quickand easy to install and do not increasethe overall size of the compressors toa great extend. Refer to page 35 forsound attenuation and code num-bers.

Mechanical vibrations Vibration isolation constitutes the pri-mary method for controlling structuralvibration. Performer® scroll compres-sors are designed to produce minimalvibration during operations. The useof rubber isolaters on the compressorbase plate or on the frame of a mani-folded unit is very effective in redu-cing vibration being transmitted fromthe compressor(s) to the unit. Rubbergrommets are supplied with all Perfor-mer® compressors. Once the supplied

rubber grommets have been properlymounted, vibration transmitted fromthe compressor base plate to the unitare held to a strict minimum. In ad-dition, it is extremely important that

the frame supporting the mountedcompressor be of suffi cient mass andstiffness to help dampen any residualvibration potentially transmitted tothe frame. For further information onmounting requirements, please referto the section on mounting assembly. The tubing should be designed soas to both reduce the transmissionof vibrations to other structures andwithstand vibration without incurringany damage. Tubing should also be

designed for three-dimensional flexi-bility. For more information on pipingdesign, please see the section entitled"Essential piping design considera-tions" p. 23.

Gas pulsation The Performer® scroll compressor hasbeen designed and tested to ensurethat gas pulsation has been optimizedfor the most commonly encounteredair conditioning pressure ratio. On

heat pump installations and otherinstallations where the pressure ratiolies beyond the typical range, testingshould be conducted under all expec-

ted conditions and operating configu-rations to ensure that minimum gaspulsation is present. If an unaccep-table level is identified, a dischargemuffl er with the appropriate resonant

volume and mass should be installed. This information can be obtained fromthe component manufacturer.


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Compressor handling

Mounting

INSTALLATION

Each Performer® scroll compressor isdelivered with two lift rings. Alwaysuse these rings when lifting the com-pressor. A spreader bar rated for the

mass of the compressor is highly re-commended to ensure a better loaddistribution. Given that the center ofgravity on the scroll is very high, theuse of one lifting lug will result in anunstable load. The compressor mass istoo great for the single lug to handle,and the risk is run that the lug couldseparate from the compressor with ex-tensive damage and possible personalinjury as a result. The use of lifting hooks closed with a

clasp and certified to lift the weight ofthe compressor is also highly recom-mended (see the adjacent figure).Always respect the appropriate rulesconcerning lifting objects of the typeand weight of these compressors.When the compressor is mounted aspart of an installation, never use the

lift rings on the compressor to lift theentire installation, which may be tooheavy for lifting in this manner.Maintain the compressor in an upright

position during all handling maneu-vers.Never apply force to the terminal boxwith the intention of moving the com-pressor, as the force placed upon theterminal box will cause extensive da-mage to both the box and the even-tual motor protection module compo-

Lock washer

HM 8 Bolt

Flat washer

Steel mounting sleeve

Rubber grommet

Nut

Compressorbase plate

28 mm

All compressors come delivered withfour rubber mounting grommets and

metal sleeve liners that serve to isolatethe compressor from the base frame. These grommets attenuate to a greatextent the transmission of compressorvibrations to the base frame. The rub-ber grommets must be compresseduntil contact between the flat washerand the steel-mounting sleeve is esta-blished. The required bolt size for the SM / SZ084 to 185 compressors is HM8. Thisbolt must be tightened to a torque of

21 Nm. The bolts and washers are sup-plied with the assembly kit.

The required bolt size for the SY / SZ240 to 380 compressors is HM10. Theminimum required flat washer out-side diameter is 27 mm. Mountingbolts must be tightened to a torque of40 Nm. These bolts and washers arenot supplied with the compressor.

Note:

The large flat washer must be positio-ned in place before shipping the unitwith the compressor installed.

SM-SZ 084 to 185


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Compressorbase plate

29

INSTALLATION

Lock washer*

HM 10 Bolt*

Large Flat*27 mm washer

Steel mounting sleeve

Rubber grommet

Nut*

36 mm

*Not supplied with compressor

Removing connectionsshipping plugs

Before the suction and discharge plugsare removed, the nitrogen holdingcharge must be released via the suc-tion schrader valve to avoid an oil mistblowout. Remove the suction plug firstand the discharge plug afterwards. Theplugs shall be removed only just be-

fore connecting the compressor to theinstallation in order to avoid moisturefrom entering the compressor. Whenthe plugs are removed, it is essentialto keep the compressor in an uprightposition so as to avoid oil spillage.

System cleanliness The refrigerant compression system,

regardless of the type of compressorused, will only provide high effi ciencyand good reliability, along with a longoperating life, if the system containssolely the refrigerant and oil it wasdesigned for. Any other substanceswithin the system will not improveperformance and, in most cases, willbe highly detrimental to system ope-rations.

The presence of non-condensablesubstances and system contaminants,

such as metal shavings, solder andflux, have a negative impact on com-pressor service life. Many of these con-taminants are small enough to passthrough a mesh screen and can causeconsiderable damage within a bearingassembly. The use of highly-hygrosco-pic polyester oil in R407C compressors

requires that the oil be exposed to the

atmosphere just as little as possible.System contamination is one of mainfactors affecting equipment reliabi-lity and compressor service life. It isimportant therefore to take systemcleanliness into account when assem-bling a refrigeration system.During the manufacturing process, cir-cuit contamination may be caused by:

● Brazing and welding oxides,

● Filings and particles from the remo-val of burrs in pipe-work,

● Brazing flux,

● Moisture and air.

Consequently, when building equip-ment and assemblies, the followingprecautions must be taken:Never drill holes into the pipe-work af-ter installation.

Tubing Only use clean and dehydratated refri-geration-grade copper tubing. Tube-cutting must be carried out so as notto deform the tubing roundness andto ensure that no foreign debris re-mains within the tubing. Only refrige-

rant-grade fittings should be used andthese must be of both a design andsize to allow for a minimum pressuredrop through the completed assem-bly. Follow the brazing instructionsnext pages.

SY-SZ 240 to 380


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heat shield

ABC

Filter driers For new installations with SY / SZ com-pressors with polyolester oil, DanfossCommercial Compressors recom-mends using the Danfoss DML 100%-

moleculair sieve, solid core filter drier.Molecular sieve filter driers with loosebeads from third party suppliers shallbe avoided. For servicing of existinginstallations where acid formation ispresent the Danfoss DCL solid corefilter driers containing activated alu-

mina are recommended. Also for newinstallations with SM compressorswith mineral oil the Danfoss DCL drieris recommended.

The drier is to be oversized rather thanundersized. When selecting a drier,always take into account its capacity(water content capacity), the systemrefrigeration capac

Documents

Danfoss Scroll SZ185S4RC