Page 1 of 2 12 LastLast
Results 1 to 13 of 17
  1. #1
    Join Date
    Aug 2001
    Posts
    200
    Installed a 3hp copland semi-hermetic 3 phase compresssor.
    Wired the compressor according to schematic. Unit is dropping temperature, but Will not pump-down. Shut-off liquid valve pressure on low side will not budge. it stays at 5psi,. De-energized liquid line solenoid same effect.
    high side is 220 psi. Is it possible that the compressor is wired wrong..

  2. #2
    Join Date
    Feb 2003
    Posts
    1,166
    Maybe you need a depressor in your hose?
    Made that mistake before
    Watts New, Ohm My, I been Electrically Commutated. Are U2.

  3. #3
    I have personally removed ALL my hoses valve core depressors. Maybe one or two hoses still have one.

    I have no use for them.
    I use those brass check valves which screw onto the ends of the hoses. That way I can recover the charge from the hi side into the lo side when I am getting off a system.

    A lot of guys dont bledd off from hi to lo and lose that amount of refrigerant.


    (just running my posts up)

  4. #4
    Join Date
    May 2004
    Posts
    12,028
    It is possible that it is overcharged and the receiver and condenser coil is full. It is also possible that your liquid pump-down valve is leaking. It is also possible that you have a combination of by-passing liquid pump-down valve and receiver valve.

    If it is a rebuilt semi, then it is possible that the rebuild is no good.

    I don't think the compressor is wired wrong but the contactor/control wiring maybe. Is the low pressure control accurate and set properly using gauges? When changing a compressor always change your contactor or relay especially if it is 3ph. If you changed it could you have wired it incorrectly?

    Got a long way to catch 12

  5. #5
    Join Date
    Feb 2003
    Posts
    1,166
    I'm the same way, toss all them depressors, don't work on much that requires them. They just slow down the flow.
    Watts New, Ohm My, I been Electrically Commutated. Are U2.

  6. #6
    Join Date
    Jun 2004
    Posts
    182
    No, it won't be the wiring. Like the others said check hose connections. If the unit is actually pumping down watch your amps also.

    Post the model and serial number with operating suction and discharge pressures along with actual voltage and we can see if the compressor is operating properly.

  7. #7
    Is there a hot gas bypass on it?
    Possible leaking solenoid?
    Hey cockroach, don't bug me!

    www.AskTheDiceman.com

    www.TheColdConspiracy.com

    www.Pennwood-HVAC.Com

    Bring Em Home....

  8. #8
    Originally posted by R12rules
    I have personally removed ALL my hoses valve core depressors. Maybe one or two hoses still have one.

    I have no use for them.
    I use those brass check valves which screw onto the ends of the hoses. That way I can recover the charge from the hi side into the lo side when I am getting off a system.

    A lot of guys dont bledd off from hi to lo and lose that amount of refrigerant.


    (just running my posts up)
    I used to be like you. No use for core depressors. But I am in HVAC now, and those damn units do not come with access service valves, just schrader ports. I hate them. But I am like you. Still no depressors, I use the brass checks.

  9. #9
    Definately not a compressor wiring issue. Close the suction service valve and see what she does. If it won't do a good vacumm with the suction service valve closed call the wholesale house and get another one.

  10. #10
    Join Date
    Feb 2004
    Location
    Medford Oregon
    Posts
    807
    if you want a valid answer tell us
    what gas are you using
    what compressor is it
    what box temp is desired
    what's your condensing temp

    saying 5 low and 220 high doesn't mean much if gas type and conditions are unknown

  11. #11
    Join Date
    Jan 2004
    Posts
    526
    Originally posted by R12rules
    I have personally removed ALL my hoses valve core depressors. Maybe one or two hoses still have one.

    I have no use for them.
    I use those brass check valves which screw onto the ends of the hoses. That way I can recover the charge from the hi side into the lo side when I am getting off a system.

    A lot of guys dont bledd off from hi to lo and lose that amount of refrigerant.


    (just running my posts up)
    i do this also but i still have my depressers in

  12. #12
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    1,795

    did your knees...

    Originally posted by refer dude 2479
    . But I am in HVAC now, [/B]
    refer dude 2479,why are you an HVAC guy after 25 y. of refrigeration.I am curious because I read somewhere that a jouney of thousand miles starts with a single step.And I am more into ref.Did your knees give in?

  13. #13

    Re: did your knees...

    Originally posted by altan
    Originally posted by refer dude 2479
    . But I am in HVAC now,
    refer dude 2479,why are you an HVAC guy after 25 y. of refrigeration.I am curious because I read somewhere that a jouney of thousand miles starts with a single step.And I am more into ref.Did your knees give in? [/B]
    I survived a ruptured disc operation in 1991 and went another 10 years but the hours and the physical nature of refrigeration were taking their toll. Also here in the Bay Area (San Francisco) a/c guys make more per hour. Sometimes I am sorry I changed though because a/c does not challenge your mind like refrig.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event