Results 1 to 12 of 12
  1. #1
    Join Date
    Apr 2012
    Location
    chicago burbs
    Posts
    76
    Post Likes

    What caused it to go bad?

    3 phase contactor went bad, white fluffy stuff by pitted end. What caused this and how? Seriously curious.

    Sent from my SPH-D710 using Tapatalk 2

  2. #2
    Join Date
    Apr 2012
    Location
    chicago burbs
    Posts
    76
    Post Likes
    Thread Starter
    Name:  uploadfromtaptalk1371865929890.jpg
Views: 320
Size:  45.8 KB

    Sent from my SPH-D710 using Tapatalk 2

  3. #3
    Join Date
    Dec 2008
    Location
    Ontario Canada
    Posts
    751
    Post Likes
    Wire not tight?

  4. #4
    Join Date
    Apr 2012
    Location
    chicago burbs
    Posts
    76
    Post Likes
    Thread Starter
    Possibly, had just spades on wires. But the corrosion on just one phase?? One terminal?

    Sent from my SPH-D710 using Tapatalk 2

  5. #5
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    13,619
    Post Likes
    Bad connections started the problem. We see that a lot due to salt air.

  6. #6
    Join Date
    Apr 2012
    Location
    chicago burbs
    Posts
    76
    Post Likes
    Thread Starter
    Heard that before, even southern coastal units vs midwest last 8/12 years beacuase of run time and salt. I think midwest is about 15/20ish? Been reading that low voltage can cause chattering as well. Just thought white stuff was a wierd corrosion, reaction to something only on 1 pole

    Sent from my SPH-D710 using Tapatalk 2

  7. #7
    Join Date
    Aug 2004
    Location
    Tucson, Az
    Posts
    338
    Post Likes
    Looks like the corrosion found on automobile battery cables.

    I've not seen that type of corrosion on a contactor.

    Where is the equipment located?
    Jim
    Tucson, Az
    Keeping the Ice Cream Frozen!

  8. #8
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    26,671
    Post Likes

  9. #9
    Join Date
    Jul 2011
    Location
    Lehigh Valley, PA
    Posts
    506
    Post Likes
    Loose connections get warm/hot and eventually burn up. Sometimes I have seen them get corroded too. I think it has something to do with the aluminum connectors on the contactor.

  10. #10
    Join Date
    Jun 2013
    Location
    N. Canada
    Posts
    873
    Post Likes
    Quote Originally Posted by leaker2 View Post
    3 phase contactor went bad, white fluffy stuff by pitted end. What caused this and how? Seriously curious.
    Chemical reaction (aka corrosion) is directly proportional to temperature.
    Note the contactor points... #3 badly burnt=most corrosion. #2 appears to have a start of corrosion (warmed), and removed #1 seems to have a touch.
    The airborne element that caused the reaction-that's another question.

    edit: not caused by loose wires.
    note the #3 points & bar overheating shows resistance BETWEEN fixed points. Remember your nursery rhymes? Twinkle twinkle little star,
    Power equals I squared R .

  11. #11
    Join Date
    Mar 2011
    Location
    Nw.Connecticut
    Posts
    307
    Post Likes
    copper conductor aluminum terminal=========== loose.

  12. #12
    Join Date
    Apr 2012
    Location
    chicago burbs
    Posts
    76
    Post Likes
    Thread Starter
    Equipment was on a rooftop with about 15 other 3_5 ton units and a couple packages. Just office buildings, but right next to I94 in chicago. Hate using spaded connectors as they are almost always loose on high volts.

    Sent from my SPH-D710 using Tapatalk 2

Posting Permissions

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

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.