Primary Side of Transformer, Feeder wire
- Thread starter kjroller
- Start date
ptonsparky
Tom
- Occupation
- EC - retired
Fused correctly?
Yeah off of a main distribution panel so a breaker I'm assuming the feeder any length is acceptable?
yes
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Yes it can be any length. Any particular reason why you think that a limit to the length may be required?
When I used to work for a commercial outfit they would apply the tap rule even thought the wires were not tapped. So the total length between primary and secondary could only be 25ft. I always thought that was inaccurate but I did not have the final say in the matter. (Also just here to learn and get better so even when I am 95% sure of an answer I like to see what others have come across)
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Thanks for the clarification. In the field you'll hear many "code rules" (I'll call them electrical myths) that do not exist. It's always good to ask the questions.
Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
The only thing I would add is the Art 450.14 about transformer disconnects. Obviously a lockable breaker works but it would need to include a location label or description on the transformer. When everything is within sight, you won't need the lockable or location description parts.
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
There is a tap rule like that, it's 240.21(B)(3) plus 240.21(C)(5). But that only applies if the conductors on the primary side of the transformers are a feeder tap. If they comply with the base requirement of 240.21 of being protected at their point of supply, the primary conductors do not have a length limit.
Cheers, Wayne