National Electrical Installation Standards

Standards as High as Your Own

Friday, April 27, 2018


I have a project that I am currently working on that requires the replacement of 15 KVA primary transformers. Upon research of the existing transformers and branch I ran across a transformer that feeds a bank of disconnect switches. The secondary side of the disconnect switches then feed back into the secondary section of the transformer and out to their specified load in underground conduit.  “see attached email with pictures of existing and notes from plans”

Can the secondary section of the transformer be used as a wireway?

Thank You, Roger Schmidt



Hey Roger thanks for your question. We were not able to view the pictures and notes and also are wondering if you meant 15 KV primary transformers especially because you mentioned separate secondary section. Possible concerns can be restricting ventilation and having sufficient space for the additional conductors. But Article 450 does not specifically prohibit conductors from being routed back through a transformer enclosure to supply other equipment.

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