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AGL_Ref_ST_ZO_E_Rev00 

5.11  Deep

 

vacuum

 

operation 

 

CAUTION 
Vacuum  operation!  Compressor  damage!

  Copeland  scroll  compressors 

should  never  be  used  to  evacuate  refrigeration  or  air-conditioning  systems. 
Operating scroll compressors in  deep vacuum could  damage internal  motor 
parts and lead to unacceptable high temperatures in the compressor housing. 

5.12  Shell

 

temperature 

During normal operation, the discharge gas as well as the compressor top shell and discharge line 
can reach temperatures up to the maximum discharge gas temperature of 135 °C 

– see 

section 3.6 

"Discharge gas temperature protection"

In a failure mode, the discharge gas temperatures can even get higher. Care must be taken to ensure 
that wiring or other materials that could be damaged by these temperatures do not touch the shell. 

5.13  Pumpdown cycle 

 

CAUTION 
Vacuum  operation!  Compressor  damage!

  Compressor  operation  outside 

the operating envelope is not allowed. 

 
A  pumpdown  cycle  to  control  refrigerant  migration  may  have  to  be  used  for  several  reasons,  for 
example when the compressor is located outdoors without any housing so that cold air blowing over 
the compressor makes the crankcase heater ineffective. 

If  a  pumpdown  cycle  is  used,  a  separate  external  check  valve  must  be  added

.  The  scroll 

discharge check valve is designed to stop extended reverse rotation and prevent high-pressure gas 
from leaking rapidly into the low side after shut-off. The check valve might in some cases leak more 
than reciprocating compressor discharge reeds, normally used with pumpdown, causing the scroll 
compressor to recycle more frequently. Repeated short cycling of this nature can result in a low oil 
situation  and  consequent  damage  to  the  compressor.  The  hysteresis  of  the  low-pressure  control 
differential has to be reviewed since a relatively large volume of gas will re-expand from the high side 
of the compressor into the low side after shutdown. 

For  pressure  control

 

setting,  never  set  the  low-pressure  limiter  to

 

shut  off  outside  of  the 

operating  envelope.

 

To  prevent  the  compressor  from  running  into  problems  during  such 

faults as loss of charge or partial blockage, the low-pressure limiter should not be set lower 
than the minimum suction pressure allowed by the operating envelope.

 

5.14  Minimum run time 

Emerson  recommends  a  maximum  of  10  starts  per  hour.  There  is  no  minimum  off  time  because 
scroll compressors start unloaded, even if the system has unbalanced pressures. The most critical 
consideration  is  the  minimum  run  time  required  to return  oil  to the  compressor  after  start-up.  The 
minimum on time becomes the time required for oil lost during compressor start-up to return to the 
compressor sump and to restore a minimal oil level that will ensure oil pick-up through the crankshaft. 
Cycling the compressor for a shorter period than this, for instance to maintain very tight temperature 
control, will result in progressive loss of oil and damage to the compressor. 

5.15  Shut-off sound 

Scroll compressors incorporate a  device that  minimizes reverse rotation. The residual momentary 
reversal of the scrolls at shut-off will cause a clicking sound, but it is entirely normal and has no effect 
on compressor durability. 

5.16  Oil level 

The oil level should be maintained at mid-point of the sight glass. 

Some systems  may contain higher than normal refrigerant charges. Systems with large coils, low 
ambient  condenser  flooding,  or  systems  with  multiple  heat  exchangers  are  among  some  system 
configurations that may require additional lubricant. 

During the system development phase, adequate oil return from the system to the compressor should 
be evaluated and qualified. 

Summary of Contents for COPELAND ZO18AG

Page 1: ...Copeland Scroll Compressors for R744 Refrigeration Applications ZO18AG to ZO46AG ZOV18AG to ZOV38AG Application Guidelines ...

Page 2: ...es 8 2 6 5 Design features 9 2 7 Dimensions 10 3 Installation 11 3 1 Compressor and drive handling 11 3 1 1 Transport and storage 11 3 1 2 Positioning and securing 11 3 1 3 Installation location 11 3 2 Compressor mounting parts 12 3 3 Shut off valves and adaptors 12 3 4 Pressure safety controls 13 3 4 1 Pressure relief valves 13 3 4 2 High pressure protection 13 3 4 3 Low pressure protection 13 3 ...

Page 3: ...rocedure 22 5 6 Run in time 23 5 7 Initial start up 23 5 8 Rotation direction 23 5 9 Start and stop routine 23 5 10 Starting sound 23 5 11 Deep vacuum operation 24 5 12 Shell temperature 24 5 13 Pumpdown cycle 24 5 14 Minimum run time 24 5 15 Shut off sound 24 5 16 Oil level 24 6 Maintenance repair 25 6 1 Qualification of workers 25 6 2 Disassembling system components 25 6 3 Provisions of legislat...

Page 4: ...AGL_Ref_ST_ZO_E_Rev00 Appendix1 Tightening torques 32 DISCLAIMER 32 ...

Page 5: ......

Page 6: ...o the corresponding provisions of legislation The Material Safety Datasheet MSDS for R744 shall be considered when working with this type of refrigerant please check this document provided by the gas supplier These instructions should be retained throughout the lifetime of the compressor You are strongly advised to follow these safety instructions 1 1 Icon explanation WARNING This icon indicates i...

Page 7: ...e current Danger of electric shock This product can cause both AC and DC earth leakage current To protect against both kinds of leakage current it is recommended to use an AC DC sensitive RCD on the power supply side WARNING High voltage Danger of electric shock and or system breakdown Disconnect and lock out power before servicing Allow drive components to electrically discharge before servicing ...

Page 8: ...liquid sub cooling 0 K Table 1 ZO V AG compressor capacity for LT applications 2 2 Matched pairs of compressor and drive The ZOV AG compressors with motor code X are offered as matched pairs with the EVM EVH drive designed in accordance with EN 60335 1 The matched pairs have been designed for maximum efficiency and reliability The drive will power the compressor control the compressor running spee...

Page 9: ...AG 4X9 EVM 344016 E20EFN 4 06 8 65 13 20 17 45 ZOV25AG 4X9 EVH 344016 R21BEN 4 06 8 65 13 20 17 45 ZOV25AG 4X9 EVH 344012 R21BEN 4 06 8 65 13 20 17 45 ZOV38AG 4X9 EVM 344016 E20EFN 6 27 13 15 20 10 27 00 ZOV38AG 4X9 EVM 344023 E20EFN 6 27 13 15 20 10 27 00 ZOV38AG 4X9 EVH 344023 R21BEN 6 27 13 15 20 10 27 00 ZOV38AG 4X9 EVH 344016 R21BEN 6 27 13 15 20 10 27 00 Evaporating temperature 35 C condensi...

Page 10: ...essor layouts and details ZO V AG compressors are available in the following BOM version BOM Suction and discharge connections T Box Mounting parts Sight glass Schraeder valve 592 Rotalock IP54 IP2X Without Yes Yes Table 4 BOM designation Please refer to the Emerson price list for more details 2 6 Application considerations 2 6 1 Qualified refrigerant and oil Qualified refrigerant R744 CO2 Copelan...

Page 11: ...count 2 6 2 Application limits CAUTION Inadequate lubrication Compressor breakdown The superheat at the compressor suction inlet must always be sufficient to ensure that no refrigerant droplets enter the compressor For a typical evaporator expansion valve configuration a minimum stable superheat of at least 20 K is required ZOV AG compressors operating envelopes depend on the running speed The env...

Page 12: ...the envelope should be respected The qualified application envelopes will change with the compressor speed At all operating conditions the minimum and maximum speed limits according to Figure 5 have to be respected With changing operating conditions the speed limits have to be determined by linear interpolation between the limits given in Figure 5 also see speed limits animation in Select software...

Page 13: ...olume LP side Internal free volume HP side PED Class ZO AG 60 bar g 45 bar g 50 C 2 8 l 0 34 l 1 ZOV AG 60 bar g 45 bar g 50 C 3 3 l 0 34 l 1 Table 6 Maximum allowable pressures PS TS internal free volume and PED category 2 6 4 Admissible temperature and relative humidity ranges ZO V AG compressors must comply with the ambient temperature and humidity ranges specified in Table 7 below both for sto...

Page 14: ...y of oil to the bearing system throughout the operating speed range of 1500 to 6000 rpm The motor in the variable speed scroll is a three phase brushless permanent magnet BPM design coupled with a rotor embedded with high energy magnets The input voltage is a series of DC pulses spaced in time to create an alternating current frequency ZO V AG compressors use a shutdown valve located in the discha...

Page 15: ...essor A B C D E F ZO18AG to ZO46AG 415 8 mm 390 2 mm 209 9 mm 67 4 mm 83 2 mm 285 8 mm Table 8 Dimensions of the ZO AG Figure 10 External dimensions of the ZOV AG Compressor A B C D E F ZOV18AG to ZOV38AG 385 8 mm 360 1 mm 179 9 mm 67 4 mm 83 2 mm 255 8 mm Table 9 Dimensions of the ZOV AG ...

Page 16: ...p NOTE The compressor is pre charged with dry air to avoid any moisture contamination 3 1 2 Positioning and securing IMPORTANT Handling damage Compressor malfunction Only use the lifting eyes whenever the compressor requires positioning Using discharge or suction connections for lifting may cause damage or leaks The compressor should be kept vertical during handling The discharge connection plug s...

Page 17: ... system System breakdown It is recommended to periodically re torque all pipe and fixing connections to the original settings after the system has been put into operation Torque settings of system valves and adaptors with Rotalock connections might decrease significantly after some time in operation Recurring temperature changes vibration and other influencing parameters can lead to expansion and ...

Page 18: ... open the drive will not operate NOTE For detailed specifications and instructions to connect the high pressure limiter to the drive please refer to the EVM EVH User Manual 3 4 3 Low pressure protection CAUTION Operation outside the application envelope Compressor breakdown A low pressure protection shall be fitted in the suction line to stop the compressor when it operates outside the envelope li...

Page 19: ... Fig 15 16 Avoid having the assembly heater inclined Fig 17 Close the lock and tighten the screw torque 2 3 Nm The excess clamp bracket may be trimmed Sharp edges must not come into contact with wires The presence of the heater shall be made evident by the posting of caution signs or markings at appropriate locations Figure 14 Figure 15 Figure 16 Figure 17 Electrical connection Connect the crankca...

Page 20: ... the compressor The stability of the refrigerant can also be affected particularly if traces of contaminant are present The problems listed under the first 2 points frequently occur simultaneously particularly since the chemical reaction speed approximately doubles with every 10 C temperature rise This directly leads to chemical reactions of the oil with the refrigerant and the compounds extracted...

Page 21: ...aximum 45 cm from the compressor for the most effective operation The further the muffler is placed from the compressor within these ranges the more effective Choose a muffler with a length of 10 to 15 cm 3 9 Sound and vibrations Vibrations during compressor operation can cause cracks which could lead to refrigerant leakage This situation must be avoided by the system manufacturer installer To thi...

Page 22: ... the oil reservoir to the compressor This value will give satisfactory results while 1 4 bar can be regarded as a minimum required value Figure 20 TraxOil OM4 and OM5 3 11 Suction line accumulator Due to Copeland scroll s inherent ability to handle liquid refrigerant for example in flooded start and defrost cycle operation an accumulator is not required in most systems To determine if a suction li...

Page 23: ...e correctly connected and that the supply voltage phases and frequency match the drive nameplate data Wiring should remain physically separated to minimize the introduction of electrical noise Before connecting the compressor ensure the supply voltage the phases and the frequency match the nameplate data For safety reasons Emerson recommends that the electrical installation be executed in complian...

Page 24: ...city failure or loss of terminal performance Precautions are required to prevent striking or bending of pins Bent or damaged pins may result in loss of hermeticity and or terminal performance Ensure correct connection of cables to the compressor terminal Fusite to avoid local overheating of Fusite pins which might lead to refrigerant leaks Cable glands have an influence on the protection class of ...

Page 25: ...f fuses has to be made according to EN 60269 1 or EN 60204 1 and drive maximum operating current MOC Not installing fuses before the compressor or selecting inappropriate fuses may result in compressor failure A conventional inherent internal line break motor protection Klixon is provided 4 8 Off cycle power consumption The drive will consume approximately 10 Watts from the drive power input line ...

Page 26: ...that case the two pressure zones of the scroll compressor need to be respected System high pressure section o Define the system high side PS compressor high side PS o Isolate the high and low pressure sections of the system by closing valves solenoid valves expansion valves or by other means o Use the internal check valve of the compressor on the discharge side or add an external check valve To pr...

Page 27: ...ut always check the following visual check of the electrics wiring fuses etc visual check of the plant for leaks loose fittings such as TXV bulbs etc compressor oil level calibration of HP LP switches and any pressure actuated valves check setting and operation of all safety features and protection devices all valves in the correct running position pressure and compound gauges fitted correctly cha...

Page 28: ...ion when the system is installed and operated Observing that suction pressure drops and discharge pressure rises when the compressor is energized allows verification of proper rotation direction There is no negative impact on durability caused by operating three phase Copeland scroll compressors in the reversed direction for a short period of time under one hour but oil may be lost Oil loss can be...

Page 29: ...eresis of the low pressure control differential has to be reviewed since a relatively large volume of gas will re expand from the high side of the compressor into the low side after shutdown For pressure control setting never set the low pressure limiter to shut off outside of the operating envelope To prevent the compressor from running into problems during such faults as loss of charge or partia...

Page 30: ...pressed air or oxygen shall not be used for purging refrigerant systems 3 Disassemble components 4 Drain recover and dispose of compressor oil as appropriate 6 3 Provisions of legislation leak check requirements According to EN 378 4 systems with a refrigerant charge of 3 kg or more shall be subject to tightness inspection at least on an annual basis The owner operator shall keep an updated logboo...

Page 31: ...al loading of the scrolls A minimum suction pressure specified in the published operating envelope must be maintained during charging Allowing the suction pressure to drop below that value may overheat the scrolls and cause early drive bearing and moving parts damage Never install a system in the field and leave it unattended when it has no charge a holding charge or with the service valves closed...

Page 32: ...gh hygroscopicity of the PAG oil To determine the actual moisture content of the lubricant samples have to be taken from the system and analysed 6 7 Oil additives Although Emerson cannot comment on any specific product from our own testing and past experience we do not recommend the use of any additives to reduce compressor bearing losses or for any other purpose Furthermore the long term chemical...

Page 33: ...ture sensor and high pressure switch Drive cooling For air cooled drives make sure that the airflow is not obstructed EMI filter Check all the wiring and check for loose or burned contacts on the board Compressor Make sure the compressor is running within the envelope Check the winding resistances from the compressor motor and the cables between compressor and drive Check for loose or burned conta...

Page 34: ...ly sized undersized discharge line can increase discharge pressure This is also true for an undersized condenser Correct the component selection as needed Check the fan motor make sure it is running properly in the right direction Check the condenser if dirt has been accumulated it will clog the airflow clean as necessary High discharge pressure is also caused by an overcharged system and high amb...

Page 35: ...ly sized Oil pump out due to high cycling rate A high cycling rate will pump oil into the system and lead to lubrication failure Oil leaves the compressor at start up and the short running time is insufficient to return the oil to the compressor via the suction side Try to limit the number of cycles to maximum 10 per hour Low gas velocity System gas velocity changes depending on temperature and lo...

Page 36: ... legislation and regulations 9 References Please visit www climate emerson com en gb for free download of Application Guidelines and Technical Information Performance and technical data The latest version of Copeland Select software with performance data and technical data is available from the webpage www climate emerson com en gb Spare parts and accessories An online version of the Emerson spare...

Page 37: ... this publication are presented for informational purposes only and are not to be construed as warranties or guarantees express or implied regarding the products or services described herein or their use or applicability 2 Emerson Climate Technologies GmbH and or its affiliates collectively Emerson as applicable reserve the right to modify the design or specifications of such products at any time ...

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