25' tap rule

[domnic]

I want to tap off a 400 amp disconnect fed with 500 kcm to a 100 amp load center 20' away i will use 1/0 wire is this 2008 code compliant?

 

[iceworm]

I want to tap off a 400 amp disconnect fed with 500 kcm to a 100 amp load center 20' away i will use 1/0 wire is this 2008 code compliant?

Sure. Put 150A fuses (or smaller) in the disconnect.

Or, look at 240.21 or 240.92 for tap rules.

ice

 

[Smart $]

On the surface, as described, it is. Without all the other details pertinent to compliance, it's hard to say

Referring to details such as MCB loadcenter has to be assumed. Then there's the calculated load vs. rating. 20' point-to-point away, or 20' of conductor away? ...etc....

 

[infinity]

Does the panel have a main?

 

[domnic]

tap

tap

The 100 panel has a 100 main breaker.

 

[kwired]

If it is outdoors there is no length limitation on your taps.

otherwise for the general rules for up to 25 foot taps make sure you meet all the requirements in 240.21(B)(2).