User Tag List

Page 2 of 3 FirstFirst 1 2 3 LastLast
Results 11 to 20 of 26

Thread: Transformer tap

  1. #11
    Join Date
    Jun 2018
    Location
    Glen bunie, md, us
    Posts
    186
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I read the following post which points to NEC 2014 Article 110.3(B) if manufacturer of the transformers allows it use to be way over rating then ok if not then no

    https://www.google.com/url?sa=t&sour...lfrnyt5FAtoDRO


    Sent from my SM-G935U using Tapatalk

  2. #12
    Join Date
    Feb 2003
    Location
    Connecticut
    Posts
    3,240
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hhsting View Post
    I read the following post which points to NEC 2014 Article 110.3(B) if manufacturer of the transformers allows it use to be way over rating then ok if not then no

    https://www.google.com/url?sa=t&sour...lfrnyt5FAtoDRO


    Sent from my SM-G935U using Tapatalk
    110.3(B) doesn't say what most people think it says.

  3. #13
    Join Date
    Jun 2018
    Location
    Glen bunie, md, us
    Posts
    186
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by david luchini View Post
    110.3(B) doesn't say what most people think it says.
    Dont follow

    Nec 2014 Article 110.3(B) says:

    Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.



    The 75kva transformer manufacturer instructions says do not load beyond 75kva then installation which does have potential to go beyond 75kva not comply per nec 2014 110.3(B). Am I missing something?

    Sent from my SM-G935U using Tapatalk

  4. #14
    Join Date
    Feb 2003
    Location
    Wisconsin
    Posts
    10,184
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hhsting View Post
    I read the following post which points to NEC 2014 Article 110.3(B) if manufacturer of the transformers allows it use to be way over rating then ok if not then no

    https://www.google.com/url?sa=t&sour...lfrnyt5FAtoDRO
    Every manufacturer I know of wants to know your loading profile, ambient temperature, cooling, and desired life before they will tell you if the chosen transformer can be used. It is all about the internal heat build up and removal in the core and coils.
    Just because you can, doesn't mean you should.

  5. #15
    Join Date
    Feb 2003
    Location
    Connecticut
    Posts
    3,240
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hhsting View Post
    Dont follow

    Nec 2014 Article 110.3(B) says:

    Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.



    The 75kva transformer manufacturer instructions says do not load beyond 75kva then installation which does have potential to go beyond 75kva not comply per nec 2014 110.3(B). Am I missing something?

    Sent from my SM-G935U using Tapatalk
    Listing and labeling don't involve the manufacturer.

  6. #16
    Join Date
    Jun 2018
    Location
    Glen bunie, md, us
    Posts
    186
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by david luchini View Post
    Listing and labeling don't involve the manufacturer.
    Ok so

    The 75kva listed or labeled transformer instructions says do not load beyond 75kva then installation which does have potential to go beyond 75kva not comply per nec 2014 110.3(B).


    Sent from my SM-G935U using Tapatalk

  7. #17
    Join Date
    Feb 2003
    Location
    Connecticut
    Posts
    3,240
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hhsting View Post
    Ok so

    The 75kva listed or labeled transformer instructions says do not load beyond 75kva then installation which does have potential to go beyond 75kva not comply per nec 2014 110.3(B).


    Sent from my SM-G935U using Tapatalk
    Do you know of any transformer that is listed with those conditions?

  8. #18
    Join Date
    Jun 2018
    Location
    Glen bunie, md, us
    Posts
    186
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by david luchini View Post
    Do you know of any transformer that is listed with those conditions?
    The other post points to UL listing.

    Besides manufacturer instruction say max loading then who would go against it and load more than max kva. AHJ cannot say anything about manufacturer instruction?

    Sent from my SM-G935U using Tapatalk

  9. #19
    Join Date
    Feb 2003
    Location
    Connecticut
    Posts
    3,240
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by hhsting View Post
    The other post points to UL listing.

    Besides manufacturer instruction say max loading then who would go against it and load more than max kva. AHJ cannot say anything about manufacturer instruction?

    Sent from my SM-G935U using Tapatalk
    Do you know of any transformer with a UL listing or with manufacturers instructions that says you cannot load it beyond it's rated kVA?

    It may exist, but I've never seen a transformer with that type of instructions.

  10. #20
    Join Date
    Jun 2018
    Location
    Glen bunie, md, us
    Posts
    186
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by david luchini View Post
    Do you know of any transformer with a UL listing or with manufacturers instructions that says you cannot load it beyond it's rated kVA?

    It may exist, but I've never seen a transformer with that type of instructions.
    What is the purpose of primary breaker? In theory would not the primary breaker if sized 125% protect the transformer from overloads?

    Sent from my SM-G935U using Tapatalk

Posting Permissions

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