Busway

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Hoyt

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I have an 800 amp 120/208 3 phase busway in a welding shop. Feeds 11 welding booths.

They would like to take half the welding booths and move them to the other side of the shop.

I would like to tap the existing 800 amp feeders and feed the relocated 5 boths on the other side of the shop.

I do not see anything in the NEC that would not allow me to do this, am I missing somehting? Is this legal? 25'-0" max tap distance?

Thanks.
 
I don't quite follow. At what point will you be connecting the wires going across to the new booth location? Upstream of the busway? Connected to the busway (e.g., by bus plug breakers)? Will you be installing a new busway on the other side of the room, to supply the 5 booths?

Please note that if you protect any given wire at its ampacity value, then you do not have a "tap," as that term is used in 240.
 
The existing feeders come into the room from the east wall and cross the room and land at the bussway along the west wall. They would like the new booths at the East wall.... so the existing feeders are currently above the new location. I would tap into them and drop a feed down to the new bussway / booths.

I would relocate a portion of the existing bussway to the new booths, I believe they are in 10'-0" sections. The relocated booths would be relocated with thier existing bussway.
 
Sounds possible.

When you connect into the feeders on the east wall are you planing on running 800 amps of conductors to the relocated bus duct or where you planning to make a tap with reduced size conductors?
 
800's, its a short feed and the sections of busway I would be relocating are rated at 800 amps. So that made the most sense to me.

They have a tight budget and I am attempting to be the most econimcal without getting myself in a tight spot.
 
Sounds good code wise, assuming proper sized box etc.

It also sounds good for the customer, save some money but still retain the flexibility of bussway.
 
So when you're done all components of the installation will retain the 800 amp ampacity rating? The would include the original feeder and the spliced conductors to the relocated busway? If all of this is true then you wouldn't have a tap you would have a splice.
 
Correct, everything would be 800 amp rated - Existing OCPD, existing feeder, new splice from feeder to relocated busway and relocated busway.

If it was a tap I believe I would be violating 240.21((b)(2)(2). I would need to termiante in a single circuit breaker or set of fuses. THis would be over 10', closer to 20'
 
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