Page 1 of 3 123 LastLast
Results 1 to 13 of 27
  1. #1
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27

    Carrier tripping internal breaker

    Carrier mod# 38AKS016 ser# 0804F17661 Compressor=Carlyle mod# 06DH5370BC1200, ser# 1003J02170

    Last week I was walking around the building with my IR temp gun checking supply temps when I discovered a system not cooling. Blower is running so I go outside and check the outdoor unit. It is the carrier listed above. I remove the panel and find the 77a internal breaker tripped. I reset it and the cond. fan started to run for a few seconds before it tripped again. I didn't have time to check it then, so I killed the disconnect and put the panel back on.

    This morning I had time to check it out. I opened it back up suspecting a bad compressor. I connected my amp clamp, turned the disconnect back on and waited for time delay. When it tried to start I was reading 117a on the motor but it didn't sound like it was turning. After a few seconds the breaker tripped. I repeated this a couple times checking amps on the other 2 motor legs. I believe they read 102 and 91.

    I killed the power and opened the terminal box at the compressor and ohmed the windings. All 3 read .4 ohms with no short to ground. Seems a little low to me but I didn't check specs. They did all read the same.

    I am ready to condemn the compressor, but maybe I am missing something. Also, the oil eye is BLACK.

    Any thoughts?

  2. #2
    Join Date
    Aug 2012
    Location
    Toronto, Canada
    Posts
    81
    If you have the right voltage to the comp then it sounds like you're drawing locked rotor amps.. Is the comp 1ph or 3 ph?

  3. #3
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27
    It's 3 phase

  4. #4
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,595
    Is this a part start motor or an across the line start?

  5. #5
    Join Date
    Aug 2012
    Location
    willowick ,oh
    Posts
    261
    try running it backwards for a bump to free it up

  6. #6
    Join Date
    Aug 2012
    Location
    Toronto, Canada
    Posts
    81
    Quote Originally Posted by heresjohnnyb View Post
    try running it backwards for a bump to free it up
    Thats a good idea... Never thought of that....

  7. #7
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    Locked up

  8. #8
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27
    Quote Originally Posted by ryan1088 View Post
    Is this a part start motor or an across the line start?
    Not sure what you mean by that

  9. #9
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27
    Quote Originally Posted by heresjohnnyb View Post
    try running it backwards for a bump to free it up
    Can't hurt to try that but if it did free it up I don't think it would be a long term fix.

  10. #10
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27
    Well, after pricing a compressor, the powers that be decided not to repair this unit. We are suppose to be starting construction on a brand new facility in about a year and unless something is mission critical they don't want to spend the money. That makes 2 out of 10 systems that are out now on the main production floor. Hopefully we don't lose any more or it's gonna start getting HOT in there.

  11. #11
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,595
    Quote Originally Posted by thelmuth View Post
    Not sure what you mean by that
    Does it have 2 contactors or just 1? It will have 6 lugs under the peckerhead instead of 3.

  12. #12
    Join Date
    Feb 2004
    Location
    Brooksville, FL
    Posts
    27
    Quote Originally Posted by ryan1088 View Post
    Does it have 2 contactors or just 1? It will have 6 lugs under the peckerhead instead of 3.
    It does have 2 contactors. Seemed weird to me. It also has 2 additional terminals with wires attached at the compressor. I didn't trace them to find out where they go and didn't really find them on the diagram for the unit.

    I find the diagram hard to understand because it has several different voltage diagrams on the same one with arrows to traces saying "460 v only" etc.

  13. #13
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,595
    I'm not a carrier guru, but both of those contactors probably have to be locked in. We had one a year ago where the 2nd contactor got hung up and caused it to short to ground. Usually it'll engage one, then shortly after you'll hear the second one hit with a clear change in pitch.

Page 1 of 3 123 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