Results 1 to 10 of 10

Thread: Using a buck-and-boost transformer on a hot case

  1. #1
    Join Date
    Aug 2019
    Posts
    5
    Post Likes

    Using a buck-and-boost transformer on a hot case

    Has anybody ever heard of using a buck-and boost transformer on a hot case in a C-store? The building has 240 and they bought a 208, 6.9kv hot case that's already on site.

  2. #2
    Join Date
    Nov 2004
    Location
    Northern Calif
    Posts
    475
    Post Likes
    Have you priced one of those? they might change their mind..and send the case back.
    I'm not young enough, to know everything...

  3. #3
    Join Date
    Aug 2002
    Location
    Southold, NY
    Posts
    32,807
    Post Likes
    Change the elements!

  4. #4
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    2,042
    Post Likes
    I thought 208/230 was used universally in most applications
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  5. #5
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    10,557
    Post Likes
    It will work but like crazzycajun said.....
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  6. #6
    Join Date
    Oct 2008
    Location
    In a kitchen with my head stuck in an oven
    Posts
    1,597
    Post Likes
    He didn't provide a make/model of the hot case, but replacing the elements with 240v ones would likely be the cheaper solution.

    FWIW: He said the case is rated for 208v at 6.9kv (probably meant kva). Some quick calculations resulted in just a smidgen over 33a of current draw under full load. If those same elements were to be supplied 240v, the current draw would be 40a (assuming it's all just a resistive load).
    He could "let it ride" as is, so long as the source wiring & breaker is rated for it. However, the heating element's expected service life may be reduced since they will be running hotter.

    240v elements will have higher resistance, so would last longer.

    I've never done a buck & boost to resolve equipment issues, so I'm no help there. I DO know they can be rather expensive.

  7. #7
    Join Date
    Aug 2019
    Posts
    5
    Post Likes
    Thread Starter
    Just to follow up for future reference, a buck & boost transformer was sized and installed by electricians and has been working for a couple of months without any problems. As often as I have found frequent burned out elements when 208v elements were installed in stores that had 240 volts or more, and with the ridiculous cost of replacing all the heaters in a hot case, I don't see why this wouldn't be just fine.

  8. #8
    Join Date
    May 2014
    Location
    Bay Area California
    Posts
    30,583
    Post Likes
    When a transformer is used in a buck/boost application, the VA rating is substantially less than the VA rating of the equipment, they aren't really that expensive. Maybe three phase is, because you'd need three of them.
    I do a triple evac with nitro to remove non condensables.

  9. #9
    Join Date
    May 2014
    Location
    Bay Area California
    Posts
    30,583
    Post Likes
    For a 6.9 kva load, looks like you need a 1 kva transformer.
    I do a triple evac with nitro to remove non condensables.

  10. #10
    Join Date
    May 2014
    Location
    Bay Area California
    Posts
    30,583
    Post Likes
    Check my 'math' . . .


    Name:  20210601_191933.jpg
Views: 111
Size:  1.15 MB

    Name:  20210601_192046.jpg
Views: 111
Size:  493.0 KB
    I do a triple evac with nitro to remove non condensables.

Posting Permissions

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