I had a talk with an Electrical Engineer yesterday about a project that he is involved with that is not in my jurisdiction, but was curious about other opinions. There is an 800A feed to this ATS, with and 800A feed going out on the load side. The engineer wants to add an additional tap, 25 ft to an electrical panel. The project has been engineered and the circuit can handle the additional load, the State Inspector says he cannot do this. His reasoning is the tap can only be made to a conductor, not the transfer switch. I don't understand his reasoning.
Tap from an ATS
- Thread starter Lcbrown
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- Location
- Lockport, IL
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- Semi-Retired Electrical Engineer
Re: Tap from an ATS
I cannot give a useful opinion on this one. I have recently moved, and my NEC books are somewhere in the garage, amongst a hundred boxes of other stuff. But I can vaguely recall having seen something like this before. From what I recall, I think that this would not be allowed. The reason has to do with the tap rule being limited to the first component encountered (e.g., starting at the transformer secondary). Beyond that first component, you need an overcurrent device to continue with another conductor to another load.
Can anyone confirm or refute my memory with a code reference, before I can get around to unpacking the right box?
[ June 16, 2005, 05:20 PM: Message edited by: charlie b ]
It sounds to me like you are confusing the definitions of "conductor" (i.e. wire) and "conductor" (something that can carry current). I would say that a lug meets the later definition, but not the former. I would also say that the NEC's use of the word "conductor" is limited to the context of something wire-like.
I cannot give a useful opinion on this one. I have recently moved, and my NEC books are somewhere in the garage, amongst a hundred boxes of other stuff. But I can vaguely recall having seen something like this before. From what I recall, I think that this would not be allowed. The reason has to do with the tap rule being limited to the first component encountered (e.g., starting at the transformer secondary). Beyond that first component, you need an overcurrent device to continue with another conductor to another load.
Can anyone confirm or refute my memory with a code reference, before I can get around to unpacking the right box?
[ June 16, 2005, 05:20 PM: Message edited by: charlie b ]
- Location
- Massachusetts
Re: Tap from an ATS
I can not think of any rule that would prohibit this.
The load side terminals of an ATS are feeders and can be tapped.
Install a set of double lugs and tap away.
I can not think of any rule that would prohibit this.
The load side terminals of an ATS are feeders and can be tapped.
Install a set of double lugs and tap away.
Re: Tap from an ATS
I'm not really sure the NEC is consistent in the use of the term "conductor". If the word "conductor" always means a "wire", why does the word "wire" occur so frequently in the NEC?
(I could be convinced its just the keep the NEC from sounding even more monotonous )
And then there are a few specific cases where conductor is clearly not just a "wire like thing".
250.118:
I'm not really sure the NEC is consistent in the use of the term "conductor". If the word "conductor" always means a "wire", why does the word "wire" occur so frequently in the NEC?
(I could be convinced its just the keep the NEC from sounding even more monotonous
)And then there are a few specific cases where conductor is clearly not just a "wire like thing".
250.118:
Steve
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