Feeder taps

[mattjglobe]

I have a 400A 480V 3 phase panelboard fed from the main switchboard, protected by a 400A breaker. I want to install a new piece of equipment that requires 300A. Can I tap off of the 400A panelboard with a 300A circuit that terminates in a 400A safety switch with 300A fuses to feed the new equipment? The switch would be located next to the 400A panelboard, not more than 10' away.

 

[Dennis Alwon]

Yes you can if you follow the rules of 240.21(B)(2)

 

[mattjglobe]

Feeder tap

Feeder tap

The new equipment will be located in another room, about 80' from the location of the 400A panelboard. I don't know yet if the new equipment has a disconnect. The feeder tap ends at the first fused disconnect, correct? After that, it is a branch circuit or sub-feeder?

 

[Dennis Alwon]

A branch circuit is the circuit conductors after the last overcurrent protective device as per definition in the NEC.

 

[Dennis Alwon]

The new equipment will be located in another room, about 80' from the location of the 400A panelboard. I don't know yet if the new equipment has a disconnect. The feeder tap ends at the first fused disconnect, correct? After that, it is a branch circuit or sub-feeder?

The new equipment can be as far away as you like as long as the tap is not over 25 feet, in your case , before it terminates in overcurrent protection rated at the ampacity of the conductors