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System design recommendations

Suction line

Piping design

Horizontal suction line sections shall have a 
slope of 0.5% in the direction of refrigerant flow 
(5 mm per meter).The cross-section of horizontal 
suction lines shall be such that the resulting 
gas velocity is at least 4 m/s. In vertical risers, a 
gas velocity of 8 to 12 m/s is required to ensure 
proper oil return. 

A U-trap is required at the foot of each vertical 
riser. If the riser is higher than 4 m, additional 
U-traps are required for each additional 4 meters.
The length of each U-trap must be as short as 
possible to avoid the accumulation of excessive 
quantities of oil (see figure below).

Gas velocities higher than 12 m/s will not 
contribute to significantly better oil return. 
However they will cause higher noise levels 
and result in higher suction line pressure 
drops which will have a negative effect on the 
system capacity. Note that the suction rotolock 
valves, which can be ordered from Danfoss 
as accessories, are designed for average pipe 
sizes, selected for systems running at nominal 
conditions. The pipe sizes selected for specific 
systems may differ from these average sizes.

The suction line must always be insulated to limit 
suction gas superheat.

Oil in a refrigeration circuit is required to 
lubricate moving parts in the compressor. During 
normal system operation small oil quantities 
will continuously leave the compressor, with 
the discharge gas. Therefore, the system piping 
shall be designed in a way which allows a good 
oil circulation, avoiding oil being trapped in 
the system and ensuring a constant oil return 
to the compressor. As long as the amount of 
oil circulating through the system is small it 
will contribute to good system operation and 
improved heat transfer efficiency. 

Lubricant getting trapped in the evaporator or 
suction lines will affect system performance and 
will ultimately lead to compressor lubrication 
failures. Where a poor oil return situation exists, 
adding lubricant will not help safeguard the 
compressor. Only a correct piping design can 
ensure adequate oil circulation maintaining safe 
oil level in the compressor.

Maneurop® NTZ compressors have been 
designed and qualified for stationary equipment 
using standard alternating power supply. 

Danfoss  does not warrant the compressors 
for use on mobile applications such as trucks, 
railways, subways, ships etc.

Discharge line

When the condenser is mounted above the 
compressor, a loop above the condenser and a 
U-trap close to the compressor are required to 
prevent liquid draining from the condenser into 
the discharge line during standstill.

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AB245486497018en-000601

Application Guidelines

Содержание Maneurop NTZ

Страница 1: ...Maneurop reciprocating compressors NTZ 50 60 Hz Group 2 R404A R507A R452A Group 1 R454C R455A Application guidelines http cc danfoss com...

Страница 2: ......

Страница 3: ...certificates 17 Pressure equipment directive 2014 68 EU 17 Low voltage directive 2014 35 EU 17 Machinery directive 2014 30 EU 17 Internal free volume 17 Operating conditions 18 Refrigerants and lubri...

Страница 4: ...to avoid safety risk This icon indicates instructions to avoid reliability risk The purpose of this guideline is informational with the intent to educate customers as to how the compressors should pr...

Страница 5: ...be operated at a return gas temperature suction gas temperature of 20 C even at low evaporating temperatures A liquid injection system is not required All components are of high quality and precision...

Страница 6: ...conditions R404A Evap temp 35 C Cond temp 40 C RGT 20 C SC 0K For full NTZ data details and capacity tables refer to selection software Coolselector 2 NT Z 4 L 048 A R1 B Motor voltage code Z Polyole...

Страница 7: ...52 1 19 NTZ271 4 7090 6 64 9 65 1 07 8210 6 64 9 65 1 24 R452A Refrigeration Compressor model 50 Hz EN12900 ratings To 35 C Tc 40 C SC 0K SH 10K 50 Hz EN12900 ratings To 35 C Tc 40 C SC 0K RGT 20 C Co...

Страница 8: ...16 3 41 0 89 1177 1 25 3 11 0 94 Compressor model 50 Hz EN12900 ratings To 35 C Tc 40 C SC 0K SH 10K 60 Hz EN12900 ratings To 35 C Tc 40 C SC 0K SH 10K Cooling capacity W Power input kW Current input...

Страница 9: ...se heater 25 98 Schrader 1 4 263 333 353 NTZ068 1 Suction rotolock 1 1 4 Discharge rotolock 1 68 82 109 118 35 33 68 Suction 147 Discharge 142 159 17 17 123 39 Threaded oil sight glass 141 224 68 HM8...

Страница 10: ...179 Discharge 176 252 288 413 32 Threaded oil sight glass Schrader 1 4 PTC crankcase heater 96 21 145 125 188 171 8 38 82 1 98 2 74 68 265 Suction rotolock 1 3 4 Discharge rotolock 1 1 4 Oil equalisat...

Страница 11: ...02 V04 352 518 117 155 232 99 Oil equalisation 3 8 Mounting hole for PTC crankcase heater 15 15 15 246 205 155 246 Suction rotolock 1 3 4 Discharge rotolock 1 1 4 233 210 125 209 98 95 Threaded oil si...

Страница 12: ...ral hours to reset and restart the compressor The trickle circuit provides the facility of heating the compressor crankcase by feeding a small current to the auxiliary winding and the run capacitor Se...

Страница 13: ...ickle circuit IOL Motor protector A C Run capacitors B Start capacitor C Common S Start winding auxiliary R Run winding main IOL Motor protector A C Run capacitors B Start capacitor C Common S Start w...

Страница 14: ...1 20 5 03 NTZ108 72 45 57 21 4 12 1 11 1 20 4 00 2 54 NTZ136 97 2 51 64 29 14 3 15 0 98 3 80 2 54 NTZ215 147 7 74 110 42 3 22 3 23 0 57 2 23 1 26 NTZ271 198 96 150 56 5 27 0 30 0 41 1 61 0 84 Three ph...

Страница 15: ...Vavg V2 3 2 xVavg voltage unbalance x 100 Internal motor protection Voltage unbalance Motor protection Three phase compressors are internally protected by a temperature current sensing bimetallic pro...

Страница 16: ...ts the settings must ensure that the compressor start up time is always less than 0 5 seconds In case of use with R454C or R455A make sure that the softstarter selected is compatible with A2L refriger...

Страница 17: ...CC China Compulsory Product Certification Models with motor voltage code 4 5 NTZ271 4 is out of CCC scope EAC Eurasian conformity mark Models with motor voltage code 4 5 Approvals and certificates Pre...

Страница 18: ...tions Danfoss recommends the use of these refrigerants with NTZ compressors Note that R404A has a small temperature glide It must therefore be charged in the liquid phase For most other aspects howeve...

Страница 19: ...HFO Blend with similar thermodynamic properties to R404A R455A is a zeotropic refrigerant with a temperature glide of about 12K and must therefore be charged in liquid phase R455A is classified A2L wi...

Страница 20: ...ollowing table 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 This switch can be set at lower values...

Страница 21: ...il in a refrigeration circuit is required to lubricate moving parts in the compressor During normal system operation small oil quantities will continuously leave the compressor with the discharge gas...

Страница 22: ...condensing temperature and condensing pressure in air cooled condensors will decrease This low pressure may be insufficient to supply enough liquid refrigerant to the evaporator As a result the evapor...

Страница 23: ...standstill and after pressure equalisation refrigerant will condensate in the coldest part of the system which may be the compressor when it is placed in a cold environment Ultimately the full system...

Страница 24: ...e migration of refrigerant and proves effective if oil temperature is maintained 10 K above the saturated LP temperature of the refrigerant Tests must thereby be conducted to ensure that the appropria...

Страница 25: ...y mounted to the base frame otherwise high vibration transmission would occur and the service life reduced Suction and discharge lines must have adequate flexibility in 3 planes Eventually vibration a...

Страница 26: ...mpressor in an upright position during all handling tasks manipulating transport storage The angle off the vertical must not exceed 15 degrees System contamination is one of the main factors that affe...

Страница 27: ...rge connection and the risk of an oil mist blow out via the suction connection will be minimal Whenever possible the compressor must be the last component to be integrated in the system It is advisabl...

Страница 28: ...rom Step 1 When the pressure slowly increases this indicates the presence of moisture In this case Steps 2 and 3 should be repeated 4 Connect the compressor to the system by means of opening the valve...

Страница 29: ...sulated on the discharge tube 10 cm far from the compressor body The maximum allowed discharge temperature is 135 C Power and current consumption shall be compared with the table values at measured ev...

Страница 30: ...120F0291 120F0241 NTZ271 120F0292 120F0243 Compressor model Single pack Multi pack Industrial pack Weight kg Dimensions mm Qty Weight kg Dimensions mm Static stacking Qty Weight kg Dimensions mm Stat...

Страница 31: ...8153122 Rotolock nut 1 Models with 1 rotolock connection Multipack 10 8153123 Rotolock nut 1 1 4 Models with 1 1 4 rotolock connection Multipack 10 8153124 Rotolock nut 1 3 4 Models with 1 3 4 rotoloc...

Страница 32: ...PTC heater 27W All models Multipack 10 PTC27W 120Z0460 PTC heater 27W All models Industry pack 50 Type Code n Description Application Packaging Pack size CSR 7701021 Relay Capacitors run 15 10 F start...

Страница 33: ...ting kit 2 cyl NTZ 096 108 Single pack 1 120Z0764 Mounting kit 2 cyl HP NTZ 136 3 4 9 Single pack 1 8156007 Mounting kit 4 cyl NTZ215 271 Single pack 1 Type Code n Description Application Packaging Pa...

Страница 34: ...document The safety and reliability risk icons are added Page 8 Nominal performance data for R454C is added Page 16 Pressure equipment directive Refrigerant Group 1 is added Page 18 Operating conditi...

Страница 35: ......

Страница 36: ...d us as distinct variable speed technology specialists Today we operate from engineering and manufacturing facilities spread across three continents AB245486497018en 000601 Danfoss DCS CC 2021 06 Our...

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