Danfoss Compressor

Selection& Application Guidelines

Performer scroll compressorsSingle 20 to 110 kW50 - 60 Hz

R22, R407C, R134a, R404A/R507A

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 ooded starts and liquid oodback .............................................................................. 18Discharge gas temperature protection (DGT) ................................................................................................................... 18Refrigerant charge limits and compressor protection .................................................................................... 19

Motor protection ............................................................................................................................................................................................................................................. 20Internal motor protection .............................................................................................................................................................................................. 20External 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 di erential ........................................................... 24Low ambient start-up .............................................................................................................................................................................................................. 24Head pressure control under low ambient conditions .................................................................................. 24Crankcase heaters ............................................................................................................................................................................................................................ 24

CONTENTS

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 ....................................................................................................................................................................................................................................... 29Tubing ..................................................................................................................................................................................................................................................................................... 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 ......................................................................................................................................................................................................................................... 34Discharge temperature protection ......................................................................................................................................................................... 35Compressor acoustic hood ....................................................................................................................................................................................................... 35

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

CONTENTS

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 by two scroll elements located in the up-per part of the compressor above the motor (see adjacent gure). Suction gas enters the compressor at the suc-tion connection. The gas then ows around the motor and enters at the bottom side through the openings as shown. Oil droplets separate from the suction gas and fall into the oil sump. All of the suction gas passes through the electrical motor, thus ensuring complete 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 above the xed scroll discharge port; this feature prevents the compressor from running backwards once the power has been switched o . Ultimately, the discharge gas leaves the compressor at the discharge connection.

The gure below illustrates the entire compression process. The center of the orbiting scroll traces a circular path around the center of the xed scroll. This movement creates symmetrical compression pockets between the two scroll elements. Low pressure suc-tion gas is trapped within each cres-cent-shaped pocket as it gets formed; continuous motion of the orbiting scroll serves to seal the pocket, which decreases in volume as the pocket moves towards the center of the scroll set increasing the gas pressure. Maxi-mum compression is achieved once a pocket reaches the center where the discharge port is located; this stage occurs after three complete orbits. Compression is a continuous process: when one quantity of gas is being compressed during the second orbit, another quantity is entering the scrolls and yet another is being discharged all at the same time.

Family, lubricant & refrigerantSM: Scroll, mineral oil, for R22SY: Scroll, POE lubricant, for R22SZ: Scroll, POE lubricant, for R407C - R134a

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

UL index

VoltageMotor voltage code:3: 200-230/3/60 4: 380-400/3/50 - 460/3/60 6: 230/3/50 7: 500/3/50 - 575/3/60 9: 380/3/60

Family, lubricant

& refrigerant

Nominalcapacity

Voltage Version Evolution Index

Version

A9S Y A A A3 0 0C4S Z S R1 8 5

5

MODEL SM/SZ 084 - 090 - 100 110 - 120 - 148 - 161SM/SZ 115 - 125 - 160

170 - 185 SY/SZ 240 - 300 SY/SZ 380

Version V R C MAMBAAAB

AAAB

Suction and discharge connection brazed rotolock brazed rotolock brazed brazed

Oil sight glass threaded threaded threaded threaded threaded threaded

Oil equalization connection 3/8 are 3/8 are 3/8 are 1/2 are 1/2 are 1/2 are

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 are 1/4 are 1/4 are 1/4 are 1/4 are 1/4 are

COMPRESSOR MODEL DESIGNATION

Performer scroll compressors are available both as single compressors and as tandem units. The example below presents the single compres-sor codi cation (technical reference

shown on compressor nameplate).

For tandem assemblies, please refer to the Performer Parallel Application Guidelines documentation.

Nomenclature

Connection details

Internal overload protector

V V: brazed S 084 - 090 100 - 110 - 120 148 - 161

Internal thermostat

C C: brazed

S 115 - 125 160 - 175 - 185

R R: rotolock

Electronic protection

module

AA ABMAMB

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

6ModelNominal

Cap. 60 HzTR

Nominal cooling capacity

W Btu/h

Powerinput

kW

A max

A

E ciency SoundpowerdB(A)

Sweptvolumecm3/rev

Displace-mentm3/h

Oilcharge

dm3

Netweight

kgCOPW/W

E.E.R.Btu/h /W

R22

SIN

GLE

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

R40

7C S

ING

LE

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 modi cation without prior noti cationFor 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 = Coe cient Of PerformanceEER = Energy E ciency Ratio

7ModelNominal

Cap. 60 HzTR

Nominal cooling capacity

W Btu/h

Powerinput

kW

A max

A

E ciency SoundpowerdB(A)

Sweptvolumecm3/rev

Displace-mentm3/h

Oilcharge

dm3

Netweight

kgCOPW/W

E.E.R.Btu/h /W

R22

SIN

GLE

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

R40

7C S

ING

LE

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 modi cation without prior noti cationFor 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 = Coe cient Of PerformanceEER = Energy E ciency Ratio

70

65

60

55

50

45

40

35

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

Co

nd. t

emp.

(C

)

Evap. temp. (C)

Condensing temp. limits

S.H. = 30 KSUPERHEAT

S.H. = 11.1 K

75

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

Co

nd

. tem

p. (C

)

Evap. temp. (C)


S.H. = 11.1 K


70

65

60

55

50

45

40

35

8

Application envelopes at dew temperatures

OPERATING ENVELOPES

The gures below show the opera-ting envelopes for SM / SY compres-sors with refrigerant R22 and for SZ compressors with refrigerants R407C, R134a, R404A and R507A. The dischar-ge temperature depends on the com-bination of evaporating temperature, condensing temperature and suction gas superheat. Because of this depen-dence, discharge temperature limits are indicated by a double line. The solid line represents the limit should the superheat be 11.1 K or less. The dashed line, on the other hand, pro-vides the limit when the superheat is 30 K. For superheat values between 11.1 K and 30 K, these two lines may

be interpolated. The operating limits serve to de ne the envelope within which reliable operations of the com-pressor are guaranteed: Maximum discharge gas tempera-

ture: +135C Maximum ambient temperature:

+63C (for SM / SZ 084 to 185), + 52C (for SY / SZ 240 to 380)

A suction superheat below 5 K is not recommended due to the risk of li-quid oodback

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

75

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

Co

nd

. tem

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

Co

nd

. tem

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

Co

nd

. tem

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

Co

nd

. tem

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 185R404A / R507A

OPERATING ENVELOPES

70

65

60

55

50

45

40

35

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

Co

nd

. tem

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

Co

nd

. tem

p. (C

)

Evap. temp. (C)


Mean temperature conditions

S.H. = 11.1 K


pressure (log)

enthalpy

Dew

Dew

Mean

Mean

10

Application envelopes at mean temperatures

Dew temperatureandmean temperaturefor R407C

OPERATING ENVELOPES

Refrigerant R407C is a zeotropic mix-ture, which causes a temperature glide in both the evaporator and condenser. When discussing evaporating and condensing temperatures therefore, it is important to indicate whether these are DEW point values or MEAN point values. In the gure below, the dashed lines re ect constant temperature and do not correspond with the constant pressure lines.

The following operating diagrams show the di erence between mean and dew temperature application en-velopes.

For a given cycle, the MEAN point temperatures are typically about 2 to 3C lower than DEW point tempera-tures. In these Selection and Applica-tion Guidelines, Danfoss Commercial Compressors displays temperatures as DEW point values. The performance tables for R407C (see p. 6-7) are also based on DEW point values.

Dew temperature

Mean temperature

Example for SZ 084 to 185

Example for SZ 084 to 185

11

Brazed version Rotolock version

Brazed Rotolock Adaptor

SM / SZ 084Suction 1 1/8 - -

Discharge 3/4 - -

SM / SZ 090Suction 1 1/8 - -

Discharge 3/4 - -

SM / SZ 100Suction 1 1/8 - -

Discharge 3/4 - -

SM / SZ 110Suction 1 3/8 - -

Discharge 7/8 - -

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

Discharge 7/8 1 1/4 3/4

SM / SZ 120Suction 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 - -

Discharge 7/8 - -

SM / SZ 161Suction 1 3/8 - -

Discharge 7/8 - -

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 and discharge connections

PIPING CONNECTIONS

Oil llconnectionand gauge port

Oil drainconnection

Oil drain

Sight glass

The oil drain connection allows oil to be removed from the sump for chan-ging, testing, etc. The tting contains an extension tube into the oil sump to more e ectively remove the oil. The connection is composed of a female 1/4" NPT tting.

Note : On SY / SZ 240-380, it is not possible to drain oil from the suction connection.

Schrader

All Performer scroll compressors come equipped with a sight glass which may be used to determine the amount and condition of the oil contained within the sump.

The oil ll connection and gauge port is a 1/4" male are connector incorpo-rating a Schrader valve.

12

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

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

ELECTRICAL CONNECTIONS AND WIRING

Motor voltage Performer scroll compressors are available in ve di erent motor vol-tages. Motor voltage code 3 and 9 for

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

Motor voltage code 3


with thermostat protector and

internal overload (S 084 - S 185)


with PTC and electronic module

(S 240 - S 380)Motor voltage

code 6Motor voltage

code 7Motor voltage

code 9

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

Voltage range 50 Hz - 340-440V 360 - 440 V 207 - 253V 450 - 550V -

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

Voltage range 60Hz 180 - 253 V 414 - 506V 414 - 506V - 517 - 632V 342 - 418 V

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

ning torque is 3 Nm. Use a 1/4 ring terminal on the power leads.

The terminal box is provided with a 29 mm hole for the power supply and a 29 mm knockout.

The protection rating of the terminal box 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 with 2 double knockouts for the power

supply and 3 knockouts for the safety control circuit.

29 mm knockout

Cover holding screw (x2)Torque: 2.2 N.m.

Discharge gas thermostat kit (optional)

Discharge gas pipe

Belt type cranckase heater (optional)

1/4 spade connector

Safety control circuit motor thermostat

Terminal box

Power supply

L N S1 S2 M1 M2

L1 L2 L3Black Blue Brown

The 2 power supply, double knockouts accommodate the following diameters: 44 mm / 13/4 hole (for a 11/4

conduit) and 34mm / 13/8 hole (for a 1 conduit),

32.1 mm / 1.26 hole and 25.4 mm / 1 hole.

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

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

Connect the internal safety thermostat with 1/4 female spade connectors.

13

Terminal box wiring forSY / SZ 240 300 380


Electronic protection module wiring

The terminal box is provided with 4 double knockouts for the power sup-ply and 4 knockouts for the safety control circuit. The 4 power supply double knockouts accommodate the following diameters:

22 mm / 7/8 hole and 16.5 mm / 0.65 knockout

22 mm / 7/8 hole and 16.5 mm / 0.65 knockout

43.7 mm / 123/32 hole and 34.5 mm / 123/64 knockout

40.5 mm / 1.59 hole and 32.2 mm / 1.27 knockout

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

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

IP ratings according to IEC 529.

The motor protection module comes preinstalled within the terminal box and is accompanied with both phase sequence protection and pre-wired thermistor connections. The module must be connected to a power supply of the appropriate voltage. The mo-dule terminals are 6.3 mm size Faston type.

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

BlackBlue

Brown

Phase sequence input

Internal control contact

Safetycircuit

Thermistorconnection

Module power24 or 115/230 vac

T T

THTH

KA

A1 A2 A3A1 160 s

A2 KA

~

~

MDGT

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 wiring diagrams 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 wiring diagrams 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

L1 L3 L2

M

A1

A2

A3


14


Short cycle timer fonction

15

Danfoss MCI soft-start controller


Legends

Compressor model Soft start referenceambient max. 40CSoft start referenceambient max. 55C

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 - 185

SY / 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 code 4 (400V / 3 / 50Hz or 460V / 3 / 60Hz) can be reduced using the Danfoss di-gitally-controlled MCI compressor soft starter. MCI soft starters are designed to reduce the starting and stopping current of 3-phase AC motors; MCI soft starters can reduce the in-rush current by up to 40%, thereby eliminating the

detrimental e ects of high starting tor-que surges and costly demand char-ges from the resultant current spike. Upon starting, the controller gradually increases the voltage supplied to the motor until full-line voltage has been reached. All settings, such as ramp-up time and initial torque, are preset at the factory and do not require modi- cation.

Suggested wiring diagrams logicCompressor models SY / SZ 240 - 300 - 380

A1A3

A2


A1A3

A2


Control device ...................................................THOptional short cycle timer (3 min) ......... 180 sControl relay ..................................................... KALiquid Line Solenoid valve ......................... LLSVCompressor contactor ................................... KMSafety lock out relay ........................................ KSPump-down control & L.P. switch ................ BPH.P. safety switch .............................................HP

Fused disconnect .............................................Q1Fuses ....................................................................F1External overload protection .........................F2Compressor motor ........................................... MMotor safety thermostat ............................. thMDischarge gas thermostat ..........................DGTMotor Protection Module ......................... MPMThermistor chain ................................................S

16

MCI with bypass contactor

Input controlled soft start

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

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

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

(13-14 contact not applicable with MCI 25C)


When the control voltage is applied to A1 - A2, the MCI soft starter will start the motor, according to the settings of the ramp-up time and initial torque

adjustments. When the control voltage is switched OFF, the motor will switch o instantaneously.

17

SYSTEM DESIGN RECOMMENDATIONS

Refrigerant charge limit and compressor protection

Performer scroll compressors incor-porate internal safety devices such as motor temperature protection, rever-se rotation protection and a dischar-ge gas check valve. Additional safety devices or system components may

however be required to ensure ade-quate protection of the compressor. Depending on the system con gura-tion and application, one or several of the following methods should be considered.

Crankcase heater When the compressor is idle, the oil temperature in the sump of the com-pressor must be maintained at no lower than 10 K above the saturation temperature of the refrigerant on the low-pressure side. This requirement ensures that the liquid refrigerant is not accumulating in the sump. A crank-case heater is only e ective if capable of sustaining this level of temperature di erence. Tests must be conducted to ensure that the appropriate oil tempe-rature is maintained under all ambient conditions (temperature and wind). However, below 5C ambient tem-perature and a wind speed of above 5 m/sec, we recommend that the heaters be thermally insulated in order to limit the surrounding energy losses.Since the total system charge may be unde ned, a crankcase heater is

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

Notes: Belt-type crankcase heater accessories are available from Danfoss (see page 34). The heater must be energized for a minimum of 12 hours before initial start-up (compressor service valves opened) and must remain energized whenever the compressor is o .Provide separate electrical supply for the heaters so that they remain ener-gized even when the machine is out of service (eg. seasonal shutdown).

Liquid line solenoid valve (LLSV)

An LLSV may be used to isolate the liquid charge on the condenser side, thereby preventing against charge transfer or excessive migration to the compressor during o -cycles.

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

Pump-down cycle

Suction accumulator

A pump-down cycle represents one of the most e ective ways to protect against the o -cycle migration of li-quid refrigerant. Once the controls has been satis ed, a solenoid valve closes on 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. This step reduces the amount of charge on the low side in order to prevent o -cycle migration. Recommended set-tings of the low-pressure pump-down switch can be found in the table on p. 22. For suggested wiring diagrams, please see p. 14-15.

A suction accumulator o ers protec-tion against refrigerant oodback at start-up, during operations or after defrosting (heat pump). Sustained and repeated liquid slugging and oodback can seriously impair the oils ability to lubricate. The suction line accumulator also protects against

o -cycle migration by providing addi-tional internal free volume to the low side of the system. The accumulator should not be sized for less than 50% of the total system charge. Tests must be conducted to determine the actual refrigerant holding capacity needed for the application.

18

DGT protection is required if the high and low pressure switch settings do not protect the compressor against opera-tions beyond its speci c application envelope. Please refer to the examples below, which illustrates where DGT protection is required (Example 1) and where it is not (Example 2).

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

HP1 = 25 bar (g) (62C)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) (-7C)HP switch setting: HP2 = 21 bar (g) (55C)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 nds its way into a compressor by means of o -cycle migration. Liquid oodback occurs when liquid refrige-rant returns to a compressor while it is running. Excessive liquid refrigerant in the 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 e ective if the system design allows for uncontrolled oodback to the compressor during running or starting. Performer scroll compressors can tolerate occasional ooded starts as long as the system charge does not exceed that given in the table in the following section. Per-former scrolls can also handle inter-mittent oodback, yet system design must be such that repeated and exces-sive oodback is not possible.

O -cycle refrigerant migration occurs when the compressor is located at the coldest part of the installation, when the 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 oodback may be detected by measuring either the oil sump temperature, which should be at least 10 K above the satu-rated suction temperature, or the dis-charge gas temperature, which should be at least 30 K above the saturated discharge temperature. If at any time during 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 the saturated discharge temperature, the lubricant will become excessively dilu-ted and tests would have to be perfor-med in order to select an appropriate compressor protection method. Repe-titive liquid oodback testing must be carried out under TXV threshold ope-rating conditions: a high pressure ratio and minimum load, along with the measurement of both suction super-heat and discharge gas temperature.

Liquid receiver

Protection against ooded starts and liquid oodback

A liquid receiver is highly recommen-ded on split systems and remote con-denser systems with a total refrigerant charge in excess of the recommended maximum for the compressor. Becau-se of the long refrigerant lines these systems have a relatively high system charge which is hard to de ne with ac-curacy. Further these types of systems quite often tend to be overcharged in the eld. 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 o -cycles, which greatly reduces the chance of refrigerant migration back to the com-pressor.On unitary or close-coupled systems, where the system refrigerant charge is expected to be both correct and de -nable the entire system charge may be stored in the condenser during pump-down if all components have been properly sized.

Discharge gas temperature protection (DGT)


70

65

60

55

50

45

40

35

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

Co

nd. t

emp.

(C

)

Evap. temp. (C)

LP1 LP2

HP2

HP1

R22

DGT -

limit

Example 1

Example 2

REC REQ

19


A discharge temperature protection device must be installed on all heat pumps. 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 135C.

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 240

S 300S 380

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

Notes: The compressor must not be allowed to cycle on the

discharge gas thermostat. Continuous operations beyond the compressors operating range will cause serious da-mage to the compressor!

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

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

Notes:For reversible heat pump systems and other speci c applications, please re-fer to section "Speci c Application Re-commendations".

BELOW charge limit ABOVE charge limit

Cooling only systems,

Packaged unitsNo test or additional safeties required

Refrigerant migration & oodback test

Crankcase heater

Cooling only systemswith remote condensor

and split system units

Refrigerant migration & oodback testCrankcase heater, because full system

charge is not de nable (risk of overcharging)

Refrigerant migration & oodback testCrankcase heater

Liquid receiver

Reversible heat pump system

Speci c tests for repetitive oodbackCrankcase heater

Discharge gas thermostat

Recommended Required No test or additional safeties required

REQREQREC

REQREQREQ

RECREC

REQREQ

The above chart represents basic guidelines for reliable compressor operations and safety. Please contact

Danfoss technical support for any deviations from these guidelines.

20

Motor protection

Internal motor protection

Compressor model OverheatingprotectionOvercurrentprotection

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 internal overload motor protection to prevent against excessive current and tempe-rature caused by overloading, low re-frigerant ow phase loss or incorrect motor rotation. The cutout current is the MCC value listed in the data sheets. While not compulsory, an additional external overload protection is still ad-visable for either alarm or manual re-set. The protector is located in the star point of the motor and, should it be activated, 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 in the motor windings. In the event of motor overheating caused by low refrigerant ow or improper motor rotation, the thermostat will open. Be-cause the thermostat is an automatic reset device, it must be wired within a lockout safety circuit with a manual re-set to restart the unit. For overcurrent and phase loss protection, an exter-nal overload protector must be used for the SM / SZ 115, 125, 160, 175 and

185 models. The table below shows the protection method for the various compressor models.

Compressor models SY / SZ 240 - 300 - 380 are delivered with a preinstalled motor protection module inside the terminal box. This device provides for e cient and reliable protection against overheating and overloading as well as phase loss/reversal.The motor protec-tor comprises a control module and PTC sensors embedded in the motor winding. The close contact between thermistors and windings ensures a very low level of thermal inertia.The motor temperature is being constantly measured by a (PTC) thermistor loop connected on S1-S2.If any thermistor exceeds its response temperature, its resistance increases above the trip level (4,500 ) and the output relay then trips (i.e. contacts M1-M2 are open). After cooling to below the response temperature (re-sistance < 2,750 ), a 5 minute time delay is activated. After this delay has elapsed, the relay is once again pulled in (i.e. contacts M1-M2 closed). The time delay may be cancelled by means of resetting the mains (L-N disconnect) for approx. 5 sec.


External motor protection All safety devices must comply with the requirements of the pertinent certi -cation authorities in the country where the compressor will be used. The exter-nal overload protector can be either a thermal overload relay or a circuit brea-ker. A thermal overload relay should be 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 maximum current expected during operations of the considered application; it can be found either in the corresponding data sheets or in the Danfoss Commer-cial Compressors selection program

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 MMT value appears as "A.Max" on the com-pressor nameplate.Further requirements for the external overload protector are: Overcurrent protection: The protector must trip within 2 minu-

tes at 110% of the Maximum Must-Trip current. Locked rotor protection: The protector must trip within 10 se-conds upon starting at a locked rotor current. Single-phasing protection: The protector must trip when one of the three phases fails.

Cycle rate limit The system must be designed in a way that guarantees a minimum compres-sor running time of 2 minutes so as to provide for su cient motor cooling after start-up along with proper oil re-turn. Note that the oil return may vary since it depends upon system design.There must be no more than 12 starts per hour (6 when a resistor soft-start

accessory is introduced); a number higher than 12 reduces the service life of the motor-compressor unit. If necessary, place an anti-short-cycle timer in the control circuit, connected as shown in the wiring diagram (p14-15). A three-minute (180-sec) time out is recommended.

Use a phase meter to establish the phase orders and connect line phases L1, L2 and L3 to terminals T1, T2 and T3, respectively. The compressor will only operate properly in a single direc-tion, and the motor is wound so that if the connections are correct, the rota-tion will also be correct.

Compressor models SM / SZ 084 to 185 incorporate an internal reverse vent valve which will react in the pre-sence of reverse rotation and will al-lows refrigerant to circulate through a by-pass from the suction to the dis-charge. Although reverse rotation is not destructive, even over long periods of time up to several days it should be corrected as soon as possible. Reverse rotation will be obvious to the user as soon as power is turned on; the com-pressor will not build up any pressure, the sound level will be abnormally high and power consumption will be minimal. If reverse rotation symptoms

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

Compressor models SY / SZ 240 to 380 are delivered with an electronic module which provides protection against phase reversal and loss at start-up. Apply the recommended wiring diagrams from page 15. The circuit should be thoroughly checked in order to determine the cause of the phase problem before re-energizing the control circuit.The phase sequencing and phase loss monitoring functions are active during a 5 sec. window 1 sec. after compressor start-up (power on L1-L2-L3). Should one 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.

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 gauge port, which must not be isolated.

Note:

Because power consumption of scroll compressors is almost directly pro-portional to discharge pressure, the high-pressure control can be used to indirectly limit the maximum current draw. A high-pressure control used in this manner however can never repla-ce an external overload protector.

High and low pressure protection

High pressure A high-pressure (HP) safety switch is required to shut down the compressor should the discharge pressure exceed the values shown in the table below. The high-pressure switch can be set to lower values depending on the application and ambient conditions. The HP switch must either be placed in a lockout circuit or consist of a manual reset device to prevent cycling around the high-pressure limit. If a discharge valve 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 must be used. Deep vacuum operations of a scroll compressor can cause internal electrical arcing and scroll instability. Performer scroll compressors exhibit high volumetric e ciency and may draw very low vacuum levels, which could induce such a problem. The minimum low-pressure safety switch (loss of charge safety switch) setting

is given in the following table. For systems without pump-down, the LP safety switch must either be a manual lockout device or an automatic switch wired 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 are also 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 shown in the table on page 12.The voltage applied to the motor terminals must lie within these table limits during both start-up and normal operations. The maximum allowable voltage

Voltage unbalance unbalance is 2%. Voltage unbalance causes high amperage over one or several phases, which in turn leads to overheating and possible motor da-mage. Voltage unbalance is given by the formula:

HP

>4 m/s

0.5%

max. 4 m

max. 4 m

0.5%

U-trap

>4m/sEvaporator

LP

8 to 12 m/s

HP

LP

Condenser

23

Essential piping design considerations

Proper piping practices should be em-ployed to ensure adequate oil return, even under minimum load conditions with special consideration given to the size and slope of the tubing coming from the evaporator. Tubing returns from the evaporator should be desi-gned so as not to trap oil and to pre-vent oil and refrigerant migration back to the compressor during o -cycles.

If the evaporator lies above the com-pressor, as is often the case in split or remote condenser systems, the addi-tion of a pump-down cycle is stron-gly recommended. If a pump-down cycle were to be omitted, the suction line must have a loop at the evapora-tor outlet to prevent refrigerant from draining into the compressor during o -cycles.

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

When the condenser is mounted at a

higher position than the compressor, a suitably sized U-shaped trap close to the compressor is necessary to prevent oil leaving the compressor from drai-ning back to the discharge side of the compressor during o cycle. The up-per loop also helps avoid condensed liquid refrigerant from draining back to the compressor when stopped (see g. 2).Piping should be designed with ade-quate three-dimensional exibility. It should not be in contact with the sur-rounding structure, unless a proper tubing mount has been installed. This protection proves necessary to avoid excess vibration, which can ultimately result in connection or tube failure due to fatigue or wear from abrasion. Aside from tubing and connection da-mage, excess vibration may be trans-mitted to the surrounding structure and generate an unacceptable noise level within that structure as well (for more information on noise and vibra-tion, see the section on: "Sound and vibration management" p.27).


g 1 g 2

Internal pressure relief valve

The SY / SZ 240 to SY / SZ 380 incorpo-rate an internal relief valve set to open between the internal high and low pressure sides of the compressor when the pressure di erential between the discharge and suction pressures sur-passes 31 to 38 bar. This safety feature prevents the com-pressor from developing dangerously high pressures should the high pres-sure cutout, for whatever reason, fail to shut down the compressor.

HP

LP Relief valve

24

Low ambient start-up Under cold ambient conditions (

25

SPECIFIC APPLICATION RECOMMENDATIONS

Low load operations It is recommended that the unit be tested and monitored at minimum load and, if possible, during low am-bient conditions as well. During con-ditions of low load on the system, the following considerations should be taken into account to ensure proper system operating characteristics. The superheat setting of the expan-sion device should be su cient to en-sure proper superheat levels during low loading periods. A minimum of 5 K stable superheat is required. In ad-dition, the refrigerant charge should be su cient to ensure proper sub-cooling within the condenser so as to avoid the risk of ashing in the liquid line before the expansion device. The expansion device should be sized to ensure proper control of the refrige-rant ow into the evaporator. An over-sized valve may result in erratic con-

trol. This consideration is especially important in manifolded units where low load conditions may require the frequent cycling of compressors. This can lead to liquid refrigerant entering the compressor if the expansion valve does not provide stable refrigerant su-perheat control under varying loads. Condenser fans should be cycled in such a way that the minimum pressu-re di erential is maintained between the suction and discharge pressures.Variable-speed fans can also be used to control the amount of heat to be re-moved from the condenser. The compressors should be run for a minimum period in order to ensure that the oil has su cient time to pro-perly return to the compressor sumps and that the motor has su cient time to cool under conditions of lowest re-frigerant mass ows.

Brazed plate heat exchangers

Brazed plate heat exchange needs very little internal volume to satisfy the set of heat transfer requirements. Consequently, the heat exchanger of-fers very little internal volume for the compressor to draw vapor from on the suction side. The compressor can then quickly enter into a vacuum condition; it is therefore important that the ex-pansion device be sized correctly and that a su cient pressure di erential across the expansion device be availa-ble to ensure adequate refrigerant feed into the evaporator. This aspect is of special concern when operating the unit under low ambient and load conditions. For further information on these conditions, please refer to the previous sections.Due to the small volume of the brazed

plate heat exchanger, no pump-down cycle is normally required. The suction line running from the heat exchanger to the compressor must be trapped to avoid refrigerant migration to the compressor.When using a brazed plate heat ex-changer as the condensing coil, a su -cient free volume for the discharge gas to accumulate is required in order to avoid excess pressure buildup. At least 1 meter of discharge line is necessary to generate this volume. To help re-duce the gas volume immediately af-ter start-up even further, the supply of cooling water to the heat exchanger may be opened before the compres-sor starts up so as to remove superheat and condense the incoming discharge gas more quickly.

Reversible heat pump systems

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. These transient modes of operation may lead to liquid refrigerant carryover (or oodback) or excessively wet re-frigerant return conditions. As such, reversible cycle applications require speci c precautions for ensuring a long compressor life and satisfactory operating characteristics. Regardless of the refrigerant charge in the system,

speci c tests for repetitive oodback are required to con rm whether or not a suction accumulator needs to be installed. A crankcase heater and dis-charge gas thermostat are required for reversible heat pump applications.The following considerations cover the most important issues in the realm of common applications. Each appli-cation design however should be tho-roughly tested to ensure acceptable operating characteristics.

26

Crankcase heaters Crankcase heaters are mandatory on reversible cycle applications given the high probability of liquid migration back to the compressor sump during

o -cycles due to the outdoor location of most units and operations during low ambient conditions.

Discharge temperature thermostat

Heat pumps frequently utilize high condensing temperatures in order to achieve a su cient temperature rise in the medium being heated. At the same time, they often require low eva-porator pressures to obtain su cient temperature di erentials between the evaporator and the outside tempera-ture. This situation may result in high discharge temperature; as such, it is mandatory that a discharge gas ther-mostat be installed on the discharge

line to protect the compressor from excessive temperatures. Operating the compressor at too high discharge temperatures can result in mechanical damage to the compressor as well as thermal degradation of the compres-sor lubricating oil and a lack of su -cient lubrication.The discharge gas thermostat should be set to shut down the compressor in the event discharge gas rises above 135C.

Discharge line and reversing valve

The Performer scroll compressor is a high volumetric machine and, as such, can rapidly build up pressure in the discharge line if gas in the line becomes obstructed even for a very short period of time which situation may occur with slow-acting, reversing valves in heat pumps. Discharge pres-sures exceeding the operating envelope may result in nuissance high pressure switch cutouts and place excess strain on both the bearings and motor. To prevent such occurrences, it is important that a 1 meter minimum discharge line length be allowed between the compressor discharge

port and the reversing valve or any other restriction. This gives su cient free volume for the discharge gas to collect and to reduce the pressure peak during the time it takes for the valve to change position. At the same time, it is important that the selection and sizing of the reversing or 4 way valve ensure that the valve switches quickly enough to prevent against too high discharge pressure and nuisance high pressure cutouts.Check with the valve manufacturer for optimal sizing and recommended mounting positions.

The use of a suction line accumulator is strongly recommended in reversi-ble-cycle applications as a result of the possibility of a substantial quantity of liquid refrigerant remaining in the evaporator, which acts as a condenser during the heating cycle. This liquid refrigerant can then return to the compressor, either ooding the sump with refrigerant or as a dynamic liquid slug when the cycle switches

back to a defrost cycle or to normal cooling operations.Sustained and repeated liquid slugging and oodback can seriously impair the oils ability to lubricate the compressor bearings.This situation can be obser-ved in wet climates where it is neces-sary to frequently defrost the outdoor coil in an air source heat pump. In such cases a suction accumulator becomes mandatory.

Suction line accumulator

SPECIFIC APPLICATION RECOMMENDATIONS

27

Sound generation in a refrigeration / air conditioning system

Typical sound and vibration in Refrigeration and Air-Conditioning systems encountered by design and service engineers may be broken down into the following three source categories.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 on the causes and methods of mitigation for each of the above sources.

SOUND AND VIBRATION MANAGEMENT

Compressor sound radiation

For sound radiating from the compres-sor, the emission path is airborne and the sound waves are traveling directly from the machine in all directions.The Performer scroll compressor is designed to be quiet and the frequen-cy of the sound generated is pushed into the higher ranges, which not only are easier to reduce but also do not generate the penetrating power of lower-frequency sound.Use of sound-insulation materials on the inside of unit panels is an e ec-tive means of substantially reducing the sound being transmitted to the outside. Ensure that no components

capable of transmitting sound/vibra-tion within the unit come into direct contact with any non-insulated parts on the walls of the unit.Because of the Performers unique de-sign of a full-suction gas-cooled mo-tor, compressor body insulation across its entire operating range is possible. Accoustic hoods are available from Danfoss Commercial Compressors as accessories. These hoods are quick and easy to install and do not increase the overall size of the compressors to a great extend. Refer to page 35 for sound attenuation and code num-bers.

Mechanical vibrations Vibration isolation constitutes the pri-mary method for controlling structural vibration. Performer scroll compres-sors are designed to produce minimal vibration during operations. The use of rubber isolaters on the compressor base plate or on the frame of a mani-folded unit is very e ective in redu-cing vibration being transmitted from the compressor(s) to the unit. Rubber grommets are supplied with all Perfor-mer compressors. Once the supplied rubber grommets have been properly mounted, vibration transmitted from the compressor base plate to the unit are held to a strict minimum. In ad-dition, it is extremely important that

the frame supporting the mounted compressor be of su cient mass and sti ness to help dampen any residual vibration potentially transmitted to the frame. For further information on mounting requirements, please refer to the section on mounting assembly.The tubing should be designed so as to both reduce the transmission of vibrations to other structures and withstand vibration without incurring any damage. Tubing should also be designed for three-dimensional exi-bility. For more information on piping design, please see the section entitled "Essential piping design considera-tions" p. 23.

Gas pulsation The Performer scroll compressor has been designed and tested to ensure that gas pulsation has been optimized for the most commonly encountered air conditioning pressure ratio. On heat pump installations and other installations where the pressure ratio lies beyond the typical range, testing should be conducted under all expec-

ted conditions and operating con gu-rations to ensure that minimum gas pulsation is present. If an unaccep-table level is identi ed, a discharge mu er with the appropriate resonant volume and mass should be installed. This information can be obtained from the component manufacturer.

28

Compressor handling

Mounting

INSTALLATION

Each Performer scroll compressor is delivered with two lift rings. Always use 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 load distribution. Given that the center of gravity on the scroll is very high, the use of one lifting lug will result in an unstable load. The compressor mass is too great for the single lug to handle, and the risk is run that the lug could separate from the compressor with ex-tensive damage and possible personal injury as a result.The use of lifting hooks closed with a clasp and certi ed to lift the weight of the compressor is also highly recom-mended (see the adjacent gure).Always respect the appropriate rules concerning lifting objects of the type and weight of these compressors.When the compressor is mounted as part of an installation, never use the

lift rings on the compressor to lift the entire installation, which may be too heavy for lifting in this manner.Maintain the compressor in an upright position during all handling maneu-vers.Never apply force to the terminal box with the intention of moving the com-pressor, as the force placed upon the terminal 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 g rommet

Nut

Compressorbase plate

28 mm

All compressors come delivered with four rubber mounting grommets and metal sleeve liners that serve to isolate the compressor from the base frame. These grommets attenuate to a great extent the transmission of compressor vibrations to the base frame. The rub-ber grommets must be compressed until contact between the at washer and the steel-mounting sleeve is esta-blished.The required bolt size for the SM / SZ 084 to 185 compressors is HM8. This bolt 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 / SZ 240 to 380 compressors is HM10. The minimum required at washer out-side diameter is 27 mm. Mounting bolts must be tightened to a torque of 40 Nm. These bolts and washers are not supplied with the compressor.

Note:

The large at washer must be positio-ned in place before shipping the unit with the compressor installed.

SM-SZ 084 to 185

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 connections shipping plugs

Before the suction and discharge plugs are removed, the nitrogen holding charge must be released via the suc-tion schrader valve to avoid an oil mist blowout. Remove the suction plug rst and the discharge plug afterwards. The plugs shall be removed only just be-

fore connecting the compressor to the installation in order to avoid moisture from entering the compressor. When the plugs are removed, it is essential to keep the compressor in an upright position so as to avoid oil spillage.

System cleanliness The refrigerant compression system, regardless of the type of compressor used, will only provide high e ciency and good reliability, along with a long operating life, if the system contains solely the refrigerant and oil it was designed for. Any other substances within the system will not improve performance and, in most cases, will be highly detrimental to system ope-rations.

The presence of non-condensable substances and system contaminants, such as metal shavings, solder and ux, have a negative impact on com-pressor service life. Many of these con-taminants are small enough to pass through a mesh screen and can cause considerable damage within a bearing assembly. 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 main factors a ecting equipment reliabi-lity and compressor service life. It is important therefore to take system cleanliness 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 ux, Moisture and air.

Consequently, when building equip-ment and assemblies, the following precautions 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 not to deform the tubing roundness and to ensure that no foreign debris re-mains within the tubing. Only refrige-

rant-grade ttings should be used and these must be of both a design and size to allow for a minimum pressure drop through the completed assem-bly. Follow the brazing instructions next pages.

SY-SZ 240 to 380

30

heat shield

ABC

Filter driers For new installations with SY / SZ com-pressors with polyolester oil, Danfoss Commercial Compressors recom-mends using the Danfoss DML 100%-moleculair sieve, solid core lter drier. Molecular sieve lter driers with loose beads from third party suppliers shall be avoided. For servicing of existing installations where acid formation is present the Danfoss DCL solid core lter driers containing activated alu-

mina are recommended. Also for new installations with SM compressors with mineral oil the Danfoss DCL drier is recommended.The drier is to be oversized rather than undersized. When selecting a drier, always take into account its capacity (water content capacity), the system refrigeration capacity and the system refrigerant charge.

Brazing and soldering

Copper to copper connections

When brazing copper-to-copper con-nections, the use of a copper/phos-phorus brazing alloy containing 5%

silver or more with a melting tempera-ture of below 800C is recommended. No ux is required during brazing.

Dissimilar metals connection

When manipulating dissimilar metals such as copper and brass or steel, the

use of silver solder and anti-oxidant ux is necessary.

Compressor connection When brazing the compressor ttings, do not overheat the compressor shell, which could severely damage certain internal components due to excessive heating. Use of a heat shield and/or a heat-absorbent compound is highly recommended. Due to the relatively sizable tubing and tting diameters used for the large scroll, a double tipped torch using acetylene is recom-mended for the S240-300-380 brazing operation.For rotolock version compressors, sol-der sleeves are available. For brazing the suction and discharge connec-tions, the following procedure is ad-vised: Make sure that no electrical wiring is connected to the compressor. Protect the terminal box and com-pressor painted surfaces from torch heat damage (see diagram). Remove the te on gaskets when brazing rotolock connectors with sol-der sleeves. Use only clean refrigeration-grade copper tubing and clean all connec-tions. Use brazing material with a mini-mum of 5% silver content.

Purge nitrogen or CO2 through

the compressor in order to prevent against oxidation and ammable con-ditions. The compressor should not be exposed to the open air for extended periods. Use of a double-tipped torch is re-commended. Apply heat evenly to Area A until the brazing temperature is reached. Move the torch to Area B and apply heat evenly until the brazing temperature has been reached there as well, and then begin adding the brazing mate-rial. Move the torch evenly around the joint, in applying only enough brazing material to ow the full circumference of the joint. Move the torch to area C only long enough to draw the brazing material

INSTALLATION

31

INSTALLATION

Maximum compressor test pressure (low side) 25 bar (g)

Maximum compressor test pressure (high side) 32 bar (g)

Maximum pressure di erence between highand low side of the compressor: 24 bar

Pressurize the system on HP side rst then LP side to prevent rotation of the scroll.

Compressor model Leak detection with refrigerantLeak detection with a mass spectrometer

SM-SY compressors Nitrogen & R22 Nitrogen & Helium

SZ compressors Nitrogen & R134a or R407C Nitrogen & Helium

Note 1: Leak detection with refrigerant may be forbidden in some countries. Check local regulations.

Note 2: The use of leak detecting additives is not recommended as they may a ect the lubricant properties.

into the joint, but not into the com-pressor. Remove all remaining ux once the joint has been soldered with a wire brush or a wet cloth. Remaining ux would cause corrosion of the tubing.

Ensure that no ux is allowed to enter into the tubing or

compressor. Flux is acidic and can cause substantial damage to the in-ternal parts of the system and com-pressor.

The polyolester oil used in SY / SZ compressors is highly

hygroscopic and will rapidly absorb moisture from the air. The compres-sor must therefore not be left open to the atmosphere for a long pe-riod of time. The compressor tting

plugs shall be removed just before brazing the compressor.

Before eventual unbrazing the compressor or any system

component, the refrigerant charge must be removed from both the high- and low-pressure sides. Failu-re to do so may result in serious per-sonal injury. Pressure gauges must be used to ensure all pressures are at atmospheric level.

For more detailed information on the appropriate materials required for bra-zing or soldering, please contact the product manufacturer or distributor. For speci c applications not covered herein, please contact Danfoss Com-mercial Compressors for further infor-mation.

System pressure test Always use an inert gas such as nitro-gen for pressure testing. Never use other gasses such as oxygen, dry air

or acetylene as these may form an in- ammable mixture. Do not exceed the following pressures:

Leak detection Leak detection must be carried out using a mixture of nitrogen and refri-gerant or nitrogen and helium, as in-dicated in the table below. Never use other gasses such as oxygen, dry air

or acetylene as these may form an

Danfoss Compressor

Documents

application envelopes

operating envelopes

hz data

dew temperatures

mean temperatures

discharge connections

piping connections

compressor model designation