Page 1 of 2 12 LastLast
Results 1 to 13 of 23
  1. #1
    Join Date
    Mar 2012
    Location
    Illinois
    Posts
    22

    dual capacitor question

    Hi everyone.
    I'm working on a condenser that had a blown 30/4 370vac370 capacitor in it.
    no supply house I called had it in stock so they told me to use a 30uf for the comp and a 4uf for the fan.
    They said just to hook up the wires the same way they were on the old one with no need to jumper the 2 commons.
    So I did what they said and only the comp kicks on, not the fan.
    am I correct in believing that I have to jumper the 2 common terminals?
    Or can something else be the reason for the fan not kicking on.
    please help.

  2. #2
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,121
    You have to jumper the common from the dual cap to one side of the single 4uf, and plug the wire that was on the cap terminal of the dual cap, to the other side of your new 4 uf. If you did it this way the motor should work.
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  3. #3
    Join Date
    Jun 2011
    Location
    Houston area
    Posts
    1,493
    Yeah, sounds like your not getting line voltage to the fan
    The picture in my avatar is of the Houston Ship Channel and was taken from my backyard. I like to sit outside and slap mosquitos while watching countless supertankers, barges and cargo ships of every shape and size carry all sorts of deadly toxins to and fro. It's really beautiful at times.....just don't eat the three eyed fish....

    ¯`·.¸¸ .·´¯`· .¸>÷÷(((°>

    `·.¸¸..· ´¯`·.¸ ¸.·´¯` ·.¸>÷÷(((°>

    .·´¯`· .¸>÷÷(((°>

    LMAOSHMSFOAIDMT

  4. #4
    Join Date
    Mar 2012
    Location
    Illinois
    Posts
    22
    That's what it was.
    I had to jump the 2 common terminals on the capacitors which is what I thought.
    Just wanted to double check myself.
    Thank you for your help!

  5. #5
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    Cap can't work if both sides aren't hooked up, just sayin

  6. #6
    Join Date
    Mar 2012
    Location
    Illinois
    Posts
    22
    Ya, that's what I thought but I am a recent tech school graduate and was told by the people at the supply house that no jumper was needed so just wanted to make sure I was on the right track before trying anything.

  7. #7
    Join Date
    Nov 2001
    Location
    east kansas
    Posts
    8,038
    Now you know about the advice given at some supply houses.

    And, BTW, direct you attention to my signature line.
    Beware of advice given by some guy on the Internet.

  8. #8
    Join Date
    Sep 2011
    Posts
    59
    30-4 Ive seen those on smaller trane units many times. Trane dealer/supplier should have them in stock... If wiring two caps together you have to wire the common together on both caps and to the com from contactor and one wire to fan on the 4 cap
    and another to herm on the 30 cap. its fairly straightforward. If they said no jumper was needed they may have thought you had a condenser motor with two brown capacitor leads... if thats the case you wont need a jumper.

  9. #9
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,121
    Quote Originally Posted by Milk man View Post
    Now you know about the advice given at some supply houses.
    +1
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  10. #10
    Join Date
    Jun 2007
    Location
    Greenwood Indiana (Indianapolis)
    Posts
    420

    Smile

    I bet you could of used a turbo cap. Usually its says 5 uf on the sticker but if you measure it with your tester its less than what the sticker says. If I need a 50 uf for instance, I connect the 30 and the 20, measure with my tester and its reading only 46-47 uf, so I add in a 5 uf to the equation and now reads 50uf.
    As iron sharpens iron so one man sharpens another Proverbs 27:17 NIV84

  11. #11
    Join Date
    Mar 2012
    Location
    Illinois
    Posts
    22
    The turbo was another option but it was 5 times the cost of buying the 30 and 4 uf separate.

  12. #12
    Join Date
    Apr 2008
    Location
    Maryland
    Posts
    18
    Turbo's can be pricey, but cheaper than going to the job twice. Plus if there hot, they usually will pay up! I keep Turbo's just for those odd ball sizes. If you have a Rheem or Ruud supplier around, they should have those capacitors.

  13. #13
    Join Date
    Sep 2008
    Location
    VA
    Posts
    1,844
    Quote Originally Posted by jedihvac View Post
    Turbo's can be pricey, but cheaper than going to the job twice. Plus if there hot, they usually will pay up! I keep Turbo's just for those odd ball sizes. If you have a Rheem or Ruud supplier around, they should have those capacitors.
    Yeah, if you add in travel cost, your time and possibly an evening or Sunday without cooling, the extra cost is a better VALUE. Many techs worry too much about dollars and cents. A majority of people will go with value and benefits even if the cost is greater, within reason.
    "The only true wisdom is in knowing you know nothing" Socrates

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