Feeder "tap"

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102 Inspector

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As a small town inspector, I am having trouble finding chapter and verse to support or deny an installation. Owner has a feeder from a disconnect that runs underground to a building approximately 300 feet away. He would like to install a tap onto this line to serve a second building and cutting the run length of a new feeder. The load calculations are no where near maxed out when considering both buildings. Can he install a splice box in the ground and tap off the feeder or does he need to run new feeders from the disconnect to the newly proposed building? Hope this make sense.
 
infinity said:
Interesting. How do tap conductors that feed a panelboard in a separate building meet to definition of a feeder? They would not be feeding the final OCPD.
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Wouldn't they be between the service equipment and the final branch circuit OCPD? That would make the tap a feeder.
 
infinity said:
Then is it actually a feeder? The OP said a feeder.
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From the 2017 NEC:

Article 100 Feeder. All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

Article 240 Tap Conductor. A conductor, other than a service conductor, that has overcurrent protection ahead of its point of supply that exceeds the value permitted for similar conductors that are protected as described elsewhere in 240.4.

Tap conductors are still feeders or branch circuits, as applicable.

Cheers, Wayne
 
petersonra said:
a tap is pretty much always a feeder
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If it has OCPD ahead of it it is likely a feeder, unless that OCPD is not deemed as being the service OCPD for some reason, or some other feeder.

If the OCPD is greater than allowed for protecting the conductor - it is a "feeder tap".

the word tap itself is not specific enough in NEC terminology without accompanying it with the word feeder for this situation.

So if OP is tapping a properly protected feeder his tap is legal if the feeder tap ends in an overcurrent device. If the conductor being tapped is already a feeder tap - you can't tap it again.
 
240.21(B). Also, the connection to the feeder does not have to be a tap, it can simply be an extension of the feeder (same size) to the other remote building. You'll need to comply with the disconnect rules (225.31 & 32). as well as the electrode requirements in 250.50 & 52.
 
The "tap" will be made after the Overcurrent Protection devise and will be sized with the same size conductor, which will then extend to a load center with a "main" disconnect incorporated in the panel. The first overcurrent device is sized to handle all the calculated load for the conductors. A grounding system will then be re-established. Additionally, we are still under the 2008 NEC. Thanks to everyone for the comments, I am digging into the book deeper and reading all the sections that have been referenced for additional education. That is why I enjoy this site!
 
102 Inspector said:
The "tap" will be made after the Overcurrent Protection devise and will be sized with the same size conductor, which will then extend to a load center with a "main" disconnect incorporated in the panel.
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You've correctly put the word tap in quotes because you do not have a tap. What you will end up with is a splice so no tap rules will apply.
 
I’m not a NEC guru, but…

IMO tap rules are in place only for the allowance of smaller wires to be used in specific circumstances with larger OCPD..
motors, feeders, etc with specific limits on lengths or locations.

a splice, as mentioned above by infinity, is when the conductors are the same size, yet protected by the same OCPD at the correct rating.
 
Hv&Lv said:
a splice, as mentioned above by infinity, is when the conductors are the same size, yet protected by the same OCPD at the correct rating.
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Correct, I would add one more thing, the splice conductors can be smaller than the conductors they're connecting to as long as they're properly protected by the OCPD ahead of the splice.
 
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