Code or Myth

[bwyllie]

I hear from time to time people say that the NEC requires 10% capacity in panelboard breaker spares and/or amperage capacity on a feeder. I cannot find it in the code, has anybody run across this or is this more of a good engineering practice?

 

[iwire]

Myth as far as the NEC

 

[infinity]

It maybe a good engineering practice to provide some room for future expansion but it's not required by the NEC. Personally if I were a client I would expect an engineer to provide some room for future expansion without asking.

 

[480sparky]

Closest you will get is 90.8(A).

 

[iwire]

Closest you will get is 90.8(A).

Which of course is not an enforcable section of the NEC.





Well it least not in my opinion.

 

[sandsnow]

90.8(A) should be a FPN. I think it used to be.

You will find inspectors/jurisdictions that treat it as a "shall be" requirement.

 

[480sparky]

Which of course is not an enforcable section of the NEC.





Well it least not in my opinion.

Why not ?

 

[iwire]

Why not ?

How could 90.8 be violated?