NEC 240 Trans secondary conductors

[dsewing]

NEC 240.21 and 92 have some specific requirements for protecting the secondary conductors of a transformer. It is not clear to me if the following is permissible:

Given data: 5MVA 3 phase delta/ungrounded Y transformer in a industrial supervised installation.

Can I put a Current transducers on each set of the secondary phase conductors located at the transformer terminals and wire them back to a overcurrent relay that will trip the transformer primary feed breaker as a sufficient means of protecting the secondary conductors. If acceptable this looks to be the cheapest means of protecting the secondary conductors.

 

[charlie]

Re: NEC 240 Trans secondary conductors

If you have to ask us, you can't do it. The intent of the Supervised Industrial Installations is to have qualified engineering supervision. Work with the engineering supervision for your protection schemes.