Up sizing breaker

[JJorg]

Hi, can you help me understand the "next common size breaker rule"
I am wondering if 4/0 AL wire running to a panel (sub feed) can be protected by 200 amps.
table 310-16 allows 180 amps for 4/0 AL at 75 degree column, can that be rounded to 200 amp by code?

thanks

 

[iwire]

Hi, can you help me understand the "next common size breaker rule"
I am wondering if 4/0 AL wire running to a panel (sub feed) can be protected by 200 amps.
table 310-16 allows 180 amps for 4/0 AL at 75 degree column, can that be rounded to 200 amp by code?

thanks

Yes, in most cases you could use a 200 amp breaker with a cable rated 180 amps.

Keep in mind this does not change the allowable load on the cable. The calculated load would have to remain under 180 amps.