Conflicting AHJ requirement regarding NEC 240.21 (C)

[electrofelon]

It is implied in 240.21(C)(2)(1)(b) "the equipment containing an overcurrent device(s) supplied by the secondary conductors...", as in a fusible safety switch... otherwise called a disconnecting means in Code speak.

Ok so you are saying that a fusible safety switch is just one of the few things that the conductors can supply/terminate to and that a non fusible switch doesnt qualify as one of those items?

I have a different interpretation and do not see an issue with a non fusible switch or transfer switch in between the transformer secondary terminals and an OCPD. I justify this by the following:

1. considering what the intent of the code is and that is to limit the load on the secondary conductors. Inserting a switch does not remove this protection
2. In terms of these code sections, I take the word "terminate" to mean "the end" of the secondary conductors, not necessarily just landing on any lug or terminal.

Admittedly, this was less ambiguous before they added the words "...equipment containing an overcurrent..." to 240.21(C)(2)(1)(b)

 

[jaggedben]

I was just trying to explain those sections. Perhaps I am not understanding what you are questioning about those sections. Maybe try it this way: All transformer secondary conductors need protection. There are some cases when the primary protection will also protect the secondary (C1). In installations where that is not the case, you have to meet one of C2 thru C6

I think what I'm questioning is this: 240.21(C) says "as specified in 240.21(C)(1) thru (C)(6)." It does not say "as specified in (1),(2),(3),(4),(5) or (6)." To me this implies that secondary conductors have to comply with all of the sections, except in as much as (2) thru (6) all begin with obviously conditional statements that clearly apply to only particular situations. (1) does not begin with such a conditional statement, and so I'm not sure why it doesn't apply to all situations, along with any of the others which are applicable.

That is, I can see how it could be read this way. Again, I'm not defending this interpretation as the correct one so much as saying that if the AHJ has this interpretation, I haven't heard a convincing argument for why it is wrong.

 

[Smart $]

Ok so you are saying that a fusible safety switch is just one of the few things that the conductors can supply/terminate to and that a non fusible switch doesnt qualify as one of those items?

I have a different interpretation and do not see an issue with a non fusible switch or transfer switch in between the transformer secondary terminals and an OCPD. I justify this by the following:

1. considering what the intent of the code is and that is to limit the load on the secondary conductors. Inserting a switch does not remove this protection
2. In terms of these code sections, I take the word "terminate" to mean "the end" of the secondary conductors, not necessarily just landing on any lug or terminal.

Admittedly, this was less ambiguous before they added the words "...equipment containing an overcurrent..." to 240.21(C)(2)(1)(b)

Well before 2014, people would just interpret it however they wanted, including connecting to a "device" without overcurrent protection.

The rest we'll have to agree to disagree and let the pertinent AHJ rule on it. Keep in mind that I said most AHJ will likely approve a switch-ocpd combo serving as a disconnecting means... but I frown on the switch being an ATS, as it has no OFF position.