Results 1 to 11 of 11
  1. #1
    Join Date
    Mar 2016
    Location
    IRAN
    Posts
    182
    Rep Power
    9

    Compressor for R22 , R134a , R410A



    Dear Friends,

    I have a question. As you know some compressors are made for using for example with just R22 or Just R134a or R410A.
    I just want to talk about bobbin of compressor not mechanical parts.
    I was talking with one of my friends, I told him for example for a compressor that was made for R22 it has bigger bobbin instead compressor that was made for R134a.
    If we use R134a instead R22 in that compressor, As result of R134a lower discharge pressure, We will decrease mechanical load on bobbin of compressor and finally bobbin of compressor will be warm.
    I told him in 2 cases bobbin of compressor get warm, If mechanical load be very high (for example when discharge pressure is very high) or if mechanical load is very low (for example we use R134a instead R22 in a compressor that is made only for R22).
    But he didn't agree with me. Please tell me what will happen if for example we use R22 instead R410A in a compressor that catalogue just let us using R410A. Please share your opinion with me.

    For make it more clear, Copeland scroll type ZP as catalogue says we can just use it with R410A, What will happen if we use it with R22 ? I told him bobbin of compressor will get warm because we decreased mechanical load very much by using R22. Is it true ? Or there is other important reason that catalogue do not permit us using other refrigerant instead R410A on ZP Copeland scroll compressor ?

    Sincerely yours.

    www.generalcooltrade.com
    Last edited by A.Mortezania; 23-03-2020 at 08:26 AM.



  2. #2
    Join Date
    Jul 2006
    Location
    USA
    Age
    73
    Posts
    867
    Rep Power
    26

    Re: Compressor for R22 , R134a , R410A

    What is a "Bobbin"

  3. #3
    Join Date
    Dec 2007
    Location
    australia
    Posts
    3,356
    Rep Power
    39

    Re: Compressor for R22 , R134a , R410A

    Quote Originally Posted by NH3LVR View Post
    What is a "Bobbin"
    I’m guessing cylinder, as a bobbin can be called a cylinder, so might be translated incorrectly.

    https://www.google.com.au/search?q=w...&client=safari
    Last edited by RANGER1; 10-07-2019 at 08:23 AM.

  4. #4
    Join Date
    Mar 2016
    Location
    IRAN
    Posts
    182
    Rep Power
    9

    Re: Compressor for R22 , R134a , R410A

    Quote Originally Posted by NH3LVR View Post
    What is a "Bobbin"
    Sorry,
    I didn't know what you call it. My mean photo is at below :

    Untitled - 1.jpg

    Let me ask my question in simple way, For example we have compressor that works only with R22, If we charge system with R134a instead R22 what will happen about compressor ?

    Sincerely yours.
    Last edited by A.Mortezania; 10-07-2019 at 12:06 PM.

  5. #5
    Brian_UK's Avatar
    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    76
    Posts
    11,192
    Rep Power
    60

    Re: Compressor for R22 , R134a , R410A

    To my thinking I would suggest that as long as the compressor design operating conditions are maintained then the bobbin/motor windings should be fine.

    1. The motor electrical loading should remain below full load current.

    2. The compressor superheat if correct should keep the bobbin within operating temperature limits. This is providing the operating temperature envelope is maintained.

    Both 1 and 2 need to be correct, you cannot operate one without the other.

    Always operate the machine within the manufacturers specification.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  6. #6
    Join Date
    Dec 2007
    Location
    australia
    Posts
    3,356
    Rep Power
    39

    Re: Compressor for R22 , R134a , R410A


  7. #7
    Brian_UK's Avatar
    Brian_UK is offline Moderator I am starting to push the Mods: of RE Site Moderator : and general nice guy
    Join Date
    Mar 2001
    Location
    Dorset
    Age
    76
    Posts
    11,192
    Rep Power
    60

    Re: Compressor for R22 , R134a , R410A

    Or there is other important reason that catalogue do not permit us using other refrigerant instead R410A on ZP Copeland scroll compressor ?


    Loss of manufacturers warranty is the first thing to fail.
    Brian - Newton Abbot, Devon, UK
    Retired March 2015

  8. #8
    Join Date
    Mar 2016
    Location
    IRAN
    Posts
    182
    Rep Power
    9

    Re: Compressor for R22 , R134a , R410A

    Quote Originally Posted by Brian_UK View Post
    To my thinking I would suggest that as long as the compressor design operating conditions are maintained then the bobbin/motor windings should be fine.

    1. The motor electrical loading should remain below full load current.

    2. The compressor superheat if correct should keep the bobbin within operating temperature limits. This is providing the operating temperature envelope is maintained.

    Both 1 and 2 need to be correct, you cannot operate one without the other.

    Always operate the machine within the manufacturers specification.
    Thanks friends

  9. #9
    Join Date
    Aug 2014
    Location
    UK
    Age
    75
    Posts
    508
    Rep Power
    25

    Re: Compressor for R22 , R134a , R410A

    When a compressor manufacturer designs a compressor, part of the design incorporates the size of the motor (HP/kw ) needed to drive the compressor when using certain refrigerant types, at different evaporating and condensing temperature conditions. Ie High Back Pressure loads (HBP) , Medium Back Pressure Loads (MBP) and Low Back Pressure loads (LBP)
    The cost of a compressor is related to the size of the motor required to start and run it.ie the bigger the HP/ kw of the motor the higher it’s cost
    So for a compressor that has to work in an HBP load situation typically air con or positive temperature cold rooms, then the motor has to be sized for it to start and run from a high load condition, say 15deg C and lower. Now if the same swept volume compressor is used in an LBP situation say minus 10 deg C down to minus 40 deg C, then because the compressor can only operate from minus 10 C and below then a smaller motor can be used.
    A good analogy is the old Prestcold compressor designation
    The Prestcold AS 75 12 L compressor was a 1/2 HP compressor that worked on R12 but only in LBP application ie below minus 15 deg C evaporating temperature . So this compressor would need to be fitted with either an MOP expansion valve or a Crankcase limit valve to prevent a motor overload condition.
    The Prestcold AS 75 12H R22L R502L was a 3/4 HP compressor that could work with R12 evaporating from plus 15 Deg C and lower , it could also work with R22 and R 502 on LBP applications evaporating from minus 10 Degree C and lower . So if this compressor was used with R22 or R502 it would need to also have either an MOP expansion valve or a crankcase limit valve, but if it was used on R12 it’s motor would be large enough to work at any temperature without the need for evaporating pressure limitation .
    In modern day compressors the motor is sized to be the most electrically efficient size for the refrigerant type and application
    In smaller semi hermetics and hermetics often a universal sized motor is used to reduce stock inventory .
    Often a cheaper compressor can be used on low temperature systems by using an LBP compressor that can only evaporate from minus 15deg C and lower and using an MOP expansion valve on a one to one system and using a Crankcase limit valve on a multiple evaporator system.
    So by using the correct controls to limit the evaporating Pressure the motor is never in an overloaded condition and is therefore safe.
    Motors use their power to do work, but if the motor is is oversized for its application this oversize portion of the motor simply produces wasted heat and uses energy for no reason.
    In screw compressor control the compressor often has current limiting capacity control . Often the compressor motors on screw compressors are very large in kw . Which means their costs are very high, but a smaller less expensive motor can be used simply by limiting the current that the motor can use by capacity controlling the compressors slide valve when the evaporating temperature is too high and would put the motor into an overloaded condition.
    So if a compressor is designed for HBP applications on say R22 then it will operate on R134A as the motor will be big enough , but if the compressor is designed for R134A and is used on R 22 then the motor will most likely be to small and may trip on overload ,but limiting the evaporating temperature may allow it to operate safely.
    Scroll compressors are slightly different due to their design. Often the scroll design changes from refrigerant types as the scroll compression channel is designed for the gas passing through it , to compress it from evap to condensing condition. Scroll compressors can overheat simply running with a high suction superheat , so scroll design is often critical to the refrigerant type as design.
    It is always worth speaking with the compressor manufacturer when thinking of using a compressor in a non standard application as there are many issues which may prove disastrous such as oil type issues ,contractor sizing etc.

  10. #10
    Join Date
    Jul 2013
    Location
    USA
    Posts
    58
    Rep Power
    11

    Re: Compressor for R22 , R134a , R410A

    Using R22 in a R410a compressor or R134a in a R22 compressor can be done, as seen here:


    The two most important things to take note of are load on the compressor and compatibility of the oil. In most air conditioning applications, the evaporator temperature is on the order of 40-50F while room temperature is generally about 70-80F. If dehumidification is not needed, the evaporator temperature can be increased for an increase in efficiency, but doing so may require measures to prevent overloading the compressor. Using a refrigerant that loads the compressor less in the first place can be one solution. Careful examination of the efficiency curves is required to determine if it would actually net an efficiency improvement.

    The oil compatibility issue is of particular note using R134a in a R22 compressor. Apart from the labor intensive process of changing the oil, it's also possible to add hydrocarbons as an oil carrier.
    DIY researcher of power electronics and embedded systems.

  11. #11
    Join Date
    Feb 2020
    Location
    United States
    Posts
    3
    Rep Power
    0

    Re: Compressor for R22 , R134a , R410A

    Isn't compression ratio also a factor here? With common ratios below 3:1 and above 2:1, they would be different depending on the design refrigerant.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •