Results 1 to 9 of 9
  1. #1
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40

    heater contactor always closed

    what is the purpose on carrier package units with a heat kit. 480v coil on the contactor is always closed? isn't that the same as just a terminal block? Then they have a normal 24v coil contactor after it that energizes when calling for heat. I have been finding alot of them burnt up.

  2. #2
    Join Date
    Jun 2009
    Location
    NYC
    Posts
    458
    What's the model# of the unit?

  3. #3
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40
    I don't have it off hand

  4. #4
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40
    hear it is 50HJ-009-641
    1008G50715

  5. #5
    Join Date
    Jul 2007
    Location
    New Jersey
    Posts
    3,031
    Heres your info / schematic on page 76.

    http://www.docs.hvacpartners.com/idc...,62aq-3sis.pdf

    It looks like you have a heat relay and heat change over relay (what ever the hell that is...never heard of it before.

    Why this is, I would like it explained also.
    “If I have seen further than others, it is by standing upon the shoulders of giants.” ~ Sir Isaac Newton


    I'm learning all the time, the tombstone will be my diploma!!!


    Did you ever stop to think, and forget to start again?

  6. #6
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40
    Yes it does have a pilot relay for heat.

  7. #7
    Join Date
    Dec 2009
    Location
    Southern US
    Posts
    504
    We had one of those that kept eating 460v contactors and the bimetal switch in the 460v loop and popping main fuses too.

    After a few trips pulled out the 460v contactor and installed a 24v contactor and a stepdown transformer to power the heat control loop. Have not had a call back since.
    I'm good at making things cold...You can ask my first two wives!

  8. #8
    Join Date
    May 2007
    Posts
    733
    Some duct heaters have primary contactors with line voltage coils that will be energized anytime the duct heater has line power and the manual reset high limit is closed, with 24V contactors for cycling on W1-W2. The 460V contactors are a safety in case the 24V contactors' points weld.

  9. #9
    Join Date
    Aug 2006
    Location
    houston
    Posts
    40
    thank fxjb that make sense. That for the help it's been bugging me.

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