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  1. #1
    Join Date
    Jan 2005
    Location
    Red Deer,Alberta
    Posts
    53

    start cap bleed resistors

    I,ve got two rural locations [bible camps actually]w/w.i.coolers,freezers,r.i.beverage coolers and other smaller refrig.equipment.I know the power is not great because of wind storms causing spikes/whathaveyou.At the one location this spring I installed metal oxide varistors on individual equip.and seams to be protecting compressor electrics where before they would fry in a storm.Owner declined to do anything more costly and utility co.won,t help either.
    At the other place start capacitors want to die frequently[measured voltages are good while there]I,ve read Copeland literature that says they want to see replacement start caps installed w/15-18kohm bleed resistors esp.if equipment is subject to short cycling due to a cple.of things.Question is :jobber start caps a lot of times don,t c/w.Should I be soldering them in?The relays are sometimes failed.Is this because start cap is discharging yet as unit starts again?

  2. #2
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,069
    :tha,t is the -Purpose o f the Resis,tor's.

  3. #3
    Join Date
    Mar 2003
    Location
    Cochrane, AB
    Posts
    610
    Quote Originally Posted by dfelt View Post
    I,ve got two rural locations [bible camps actually]w/w.i.coolers,freezers,r.i.beverage coolers and other smaller refrig.equipment.I know the power is not great because of wind storms causing spikes/whathaveyou.At the one location this spring I installed metal oxide varistors on individual equip.and seams to be protecting compressor electrics where before they would fry in a storm.Owner declined to do anything more costly and utility co.won,t help either.
    At the other place start capacitors want to die frequently[measured voltages are good while there]I,ve read Copeland literature that says they want to see replacement start caps installed w/15-18kohm bleed resistors esp.if equipment is subject to short cycling due to a cple.of things.Question is :jobber start caps a lot of times don,t c/w.Should I be soldering them in?The relays are sometimes failed.Is this because start cap is discharging yet as unit starts again?
    You can use crimp connectors to hold the resistors, and yes they are there to protect the start relay from arcing.

  4. #4
    Join Date
    Feb 2004
    Location
    Medford Oregon
    Posts
    807
    a potential relay is normally closed, if on shut down, any voltage is in the start cap, it will discharge across the relay points, eventually burning them out. That's why they are REQUIRED by Copeland and Tecumseh on any compressor using a potential relay!.

  5. #5
    Join Date
    Jul 2009
    Location
    In a mechanical room....
    Posts
    1,888
    Do you know how many hits Metal oxide varistor's are good for? One good hit and they are done they work but it's a one time deal.

  6. #6
    Join Date
    Mar 2001
    Posts
    1,516
    Get a baggie of 10 @ Johnstone with the terminals already on em G32-082
    One way to outthink people is to make them think you think. They'll think you're not really thinking what you're trying to get them to think you think...........

  7. #7
    Join Date
    Oct 2008
    Location
    OFFICES IN : ARIZONA - NEVADA - TEXAS
    Posts
    258
    An aftermarket adjustable potential relay would work great for your problem.

  8. #8
    Join Date
    Jul 2004
    Location
    NJ
    Posts
    1,801
    I always install start capacitors with resistors. I don't solder them, don't even need to use spade connectors (have done that too); just put the leads through the holes on the capacitor terminals and twist them nicely with your needlenose. It will do the job.

  9. #9
    Join Date
    Jan 2010
    Posts
    6,624
    I always thought the resistors were to minimize the arc when the contacts open the start winding.

  10. #10
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,069
    its to eliminate the arc when the relay resets to its N.C position.

    The resistor bleeds start cap charge so it will not discharge through the start winding when the compressor comes to a stop. If this is allowed to happen, the contacts will arc. And in time..will weld closed.

  11. #11
    Join Date
    Jan 2010
    Posts
    6,624
    So its not to bleed the charge during the off cycle?

  12. #12
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,069
    nope, its to bleed the charge during the on cycle.

  13. #13
    Join Date
    Jan 2010
    Posts
    6,624
    Refrigeration & Air Conditioning Technology 5th Edition must have it wrong read Unit 20.11

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