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  1. #14
    Join Date
    Jan 2005
    Location
    Houston TX
    Posts
    874

    Wye-Delta part V

    First off an apology to acjourneyman, I should learn to read a little closer. These are the original contactors according to the starter manufacturer Cutler-Hammer and the Trane starter ID #. That's why I plan on contacting them on Monday, hell I may call Trane also. The more the merrier. Guys, thanks alot for all your advice. It is truly appreciated-GEO

  2. #15
    Join Date
    Jan 2005
    Location
    Houston TX
    Posts
    874

    Wye-Delta Grand Finale'

    As promised I got all my answers today. The contactor size has nothing to with amps or volts (go figure) NEMA sizing only has to do with motor horsepower. The motor I'm dealing with is 240 horsepower and that is border line between a size 5 and 6 contactor, not a size 4 as is in there now. That would explain all the extra burnt contacts sets I found laying on the work bench. I think they have been changing contacts every year since 1982. That year also played a key role to my fact finding. That's the year Trane change venders with their starters from G/E to Cutler-Hammer, now Eaton, Cutler-Hammer. Ironic part of it all is the customer won't want to spend the money to upgrade to the right size contactors. It is their chiller and I'm only the messenger. Again thanks to all.-GEO

  3. #16
    Join Date
    Sep 2004
    Location
    Kansas City, Kansas, United States
    Posts
    13,832
    i thought it was 57.5%?????????

    Quote Originally Posted by Randy S. View Post
    Theoretically the "main" and "delta" contactors each only carry 67% of the rated full load when running.

    The "star" and "main" would be the ones taking the most beating on start up.

    Is there a big voltage drop at start up?
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  4. #17
    Join Date
    May 2001
    Location
    Western Wa
    Posts
    1,837
    Methinks you right.

    I must have had a snootful of 123.
    God Bless our Veterans

    God Bless the USA

  5. #18
    Join Date
    Sep 2004
    Location
    Kansas City, Kansas, United States
    Posts
    13,832
    what??
    123 is bad for you????????????????

    Quote Originally Posted by Randy S. View Post
    Methinks you right.

    I must have had a snootful of 123.
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  6. #19
    Join Date
    Jul 2006
    Location
    The Great country of Texas
    Posts
    429
    Quote Originally Posted by ga1279 View Post
    As promised I got all my answers today. The contactor size has nothing to with amps or volts (go figure) NEMA sizing only has to do with motor horsepower. The motor I'm dealing with is 240 horsepower and that is border line between a size 5 and 6 contactor, not a size 4 as is in there now. That would explain all the extra burnt contacts sets I found laying on the work bench. I think they have been changing contacts every year since 1982. That year also played a key role to my fact finding. That's the year Trane change venders with their starters from G/E to Cutler-Hammer, now Eaton, Cutler-Hammer. Ironic part of it all is the customer won't want to spend the money to upgrade to the right size contactors. It is their chiller and I'm only the messenger. Again thanks to all.-GEO
    1st of all, it is 57% on each leg V x A x 1.73. That's why it is called a reduced voltage start because you have the windings in series. You have to remember, "S" is already pulled in before amperage is applied. 1M is pulled in by the aux of "S" and you are tying together 1/2 of a winding in series so the contact is not seeing the full brunt of current. I have seen this on a R-113, Carrier 19C that took almost one minute to get to speed. Scared the hell out of me the first time I started it because I had only been exposed to 460 volt chillers.
    "I'm from Texas, what country are you from?"

  7. #20
    Join Date
    Jan 2005
    Location
    Houston TX
    Posts
    874

    Wye-Delta Epilog

    Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed

  8. #21
    Join Date
    Sep 2004
    Location
    Kansas City, Kansas, United States
    Posts
    13,832
    so the problem was indeed undersized contactors from trane??
    is there a service bulletin??????????

    Quote Originally Posted by ga1279 View Post
    Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  9. #22
    Join Date
    Jul 2006
    Location
    The Great country of Texas
    Posts
    429
    Quote Originally Posted by ga1279 View Post
    Stickerhead; Thanks for the comeback, but I had already had gotten my answers from Tech. Services @ Eaton Cutler- Hammer who originally manufactured the starter for Trane (according to Trane guidelines). Even in a Y/D starter all current in, matches all the current out, as in locked rotor and ramp up. The problem was not one of lack of acceleration on start-up, but undersized contactors, as the motor was up to speed within 10 seconds-GEO I'm closed
    Wonder how many others out there "were" like yours!
    "I'm from Texas, what country are you from?"

  10. #23
    yeah it is scarey!!!!!!!!!!!

    Quote Originally Posted by stickerhead View Post
    Wonder how many others out there "were" like yours!

  11. #24
    Join Date
    Jan 2005
    Location
    Houston TX
    Posts
    874

    Wye-Delta (That's all Folks)

    I have no idea, except to say that since the chiller[s] have been in service since Jan 1982 I would not waste my time trying for a service bulletin or compensation. The original building owners (when the chillers were installed) were actually lead to believe that changing contacts every year was part of the annual inspection. I also find it curious that it took 27 years to find the real problem. In that time the owners spent enough money to replace both starters completely. Oh well life goes on.-GEO.

  12. #25
    Join Date
    Nov 2008
    Posts
    1,673
    Quote Originally Posted by ga1279 View Post
    The contactor size has nothing to with amps or volts (go figure) NEMA sizing only has to do with motor horsepower.
    Amps times volts times a factor = hp. It's the same thing. And a motor load is harder on the contacts than a resistive load.

    In general, good closed contacts at rated load current should read less than 30 mV, with bad reading more than 100 mV but I don't know if this rule applies to humongous contacts like these.

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