80% Breaker Loading/Trip Setting 125% above load)

[kingpb]

If I have a 100% rated power circuit breaker (800A) feeding a MLO 800A rated panelboard. I believe I can load the panel to 800A and do not have to limit it to 640A since it doesn't have a min breaker ( or if I did it isn't 100% rated).

Looking for thoughts on this.

 

[jaggedben]

I believe the panelboard itself needs to be listed at 100% along with the breakers you plan to put in it.

Your 100% rated circuit breaker would allow you to feed 800A of continuous load to a 1000A rated panelboard without using a 1000A breaker.

 

[david luchini]

If I have a 100% rated power circuit breaker (800A) feeding a MLO 800A rated panelboard. I believe I can load the panel to 800A and do not have to limit it to 640A since it doesn't have a min breaker ( or if I did it isn't 100% rated).

Looking for thoughts on this.

You are not limited to 640A on an 800A panel with a standard breaker. If the panel is rated 800A, you can put an 800A load on it.

You can put 800A of non-continuous load on an 800A panel with a standard breaker.

You can put 800A of continuous load on an 800A panel with a 100% rated breaker.

 

[jaggedben]

Sorry, I assumed without reading carefully that the load must be continuous, because that's when it would be an issue. Otherwise there is not any issue.