ECN Forum Forums Code Related Discussion NEC & other Code issues Tap rules

Bob, there is one condition for an indoor tap exceeding 25' for a high bay building you forgot about that one. Of course this tap has the "qualified persons" caveat. Back to our 10' tap rule: If I'm wrong on this one, I would like to know. My understanding is based on information from Jim Pauley of Square D. I think that what he taught that day made sense. So if you are installing a tap that requires a 600 amp switch, and the load is only 410 amps, I guess I'd put in an 11 foot tap :-) Maybe some of our more learned monitors and book writers will express their opinions. Good to spar with you Bob.

Another thought: For our 10' tap rule, we are not required to fuse it in any way, we are only asked to size our tap conductors to minimum 1/10 the size of the overcurrent device on the feeder and to be adaquate size for the load and have the ampacity of the device they terminate at. If this device is a MLO panel, or a safety switch, makes no difference. If it is a CB or a MLO makes no difference. Not required to terminate in a single set of fuses or a CB. When we move to the 25' rule we must terminate in a CB or single set of fuses.

George


Thank you and I feel the same way.

How about looking at this thread and giving your opinion.


https://www.electrical-contractor.net/ubb/Forum2/HTML/001514.html

Bob [ Iwire]:

thanks for getting me straght with me with the tap rules here. i am accommodated [ adapted] with metric mesurement for long time.

and one more question it came up in my mind here about the transformer tap here


quote:
There are times outside for transformer secondary conductors you can tap longer than 25' feet. Service conductors come to mind.

sure bob, but if the tap is super long run from the transformer to the ocpd like 100 feet [33 meter] away from transformer you have to put a ocpd at the transformer or not bear in mind this is a secondary side.

merci, marc

One can install breakers/fuses smaller in ampacity than the rated enclosure they are installed into, as long as the breaker/fuse is listed ('fits') for the enclosure.
So a 40 amp breaker/fuse can be installed in a 60 amp rated enclosure fed by 8 AWG. See Art 240 and Art 408.
What some may want to do (possibly exceeding code requirements) is up to the individual, but code is minimum and an inspector cannot ask for anything more.
Some of us have installed work a certain way as a practice, and when we see a 'code' minimum installation we may cringe, but it is permitted none the less.

Pierre