lost rule

[george lohri]

hi where is the breaker down sizing rule thanks

 

[cadpoint]

Come on and pony up some more information as the the nature of the service that your trying to apply a circuit breaker too ? :roll:

 

[mdshunk]

Conductor de-rating, perhaps?

 

[infinity]

One place would be when sizing a feeder for more than one motor. Look at 430.62.

 

[Dennis Alwon]

hi where is the breaker down sizing rule thanks

You can often downsize a breaker as long as the load is not greater than the breaker capacity. More often one can upsize a breaker---
Article 240.4(B). It is really about upsizing the breaker but gives the rules for when you can. Thus it will tell you when you cannot upsize.

Art. 240.4(C) says if the OCP is over 800 amps you cannot upsize at all.

 

[Pierre C Belarge]

You can often downsize a breaker as long as the load is not greater than the breaker capacity. More often one can upsize a breaker---
Article 240.4(B). It is really about upsizing the breaker but gives the rules for when you can. Thus it will tell you when you cannot upsize.

Art. 240.4(C) says if the OCP is over 800 amps you cannot upsize at all.

I would bet all of Dennis's money that the section number that Dennis posted is what the OP is referencing.

 

[Dennis Alwon]

I would bet all of Dennis's money that the section number that Dennis posted is what the OP is referencing.

Good morning Pierre--- that was the most generous offer I heard in weeks.:grin:

 

[Pierre C Belarge]

Good morning Pierre--- that was the most generous offer I heard in weeks.:grin:

It is a safe enough bet...only don't post any of your accounts just yet, this site sometimes produces some wacky ideas. If I should lose the bet, we will start a collection for you. :wink: