Transformer 25 foot rule 240.21 Clarification

[kjroller]

In Article 240.21 C(6) it states as one of the conditions that "secondary conductors shall be terminated on a single circuit breaker or set of fuses". Can I use the Main Breaker on the panelboard it will feed as the single circuit breaker? Or does it have to be separate from the panelboard as the panel board will feed multiple different lighting loads? (We are assuming the rest of the requirements are met)

In Article 240.21 C(1) Industrial installation it says "if all overcurrent devices are grouped" what does that mean?

Another question would be is there any instance where a transformer cant feed a general Panel as long as the secondary requirements are met?

Last question can I be over 25ft if I put a disconnect in line with the secondary conductors before it gets to the panel?


Let me know what you think thank you for your time

 

[wwhitney]

In Article 240.21 C(6) it states as one of the conditions that "secondary conductors shall be terminated on a single circuit breaker or set of fuses". Can I use the Main Breaker on the panelboard it will feed as the single circuit breaker?

Yes.

Last question can I be over 25ft if I put a disconnect in line with the secondary conductors before it gets to the panel?

Sure, as long as the disconnect is within 25' of wire length from the secondary terminals, and you comply with the rest of 240.21(C)(6). The conductors after the disconnect are not subject to 240.21(C).

No opinion on your other two questions.

Cheers, Wayne

 

[don_resqcapt19]

Q 2. 240.21(C)(3)(2) permits the use of multiple OCPDs for the protection of the secondary conductors. Those OCPDs must be grouped with each other. This would require multiple secondary OCPDs unless you have switchgear or switchgear as 408.36 requires a single OCPD for a panelboard.

Q3. As long as both the secondary conductors and the panelboard are protected, there is nothing more.