Same Size Breakers in Seires 1

[rgpe]

Is there any NEC requirement or guidelines relating to breakers of the same ampacity in series?
This would be a situation where electrical system coordination is not necessary.

For example, a 400A main breaker in a panelboard in series with a 400A branch breaker in the same panelboard. Another example would be a feeder requiring a 400A breaker that feeds a 400A panelboard with a 400A main breaker in the panelboard.

 

[dpc]

It's not a Code violation and is done all the time.

 

[dpc]

It's actually pretty common when the panelboard or whatever is some distance from the main switchboard and maybe several floors away.

 

[peebee]

You could feed an 800A from a 400A so long as the cable is protected.