480V breaker on a 240V system

FaradayFF

Senior Member
Location
California
Greetings,
Can one use a 480V, 3 pole breaker on a 240V, 3 phase system? Is that kosher?
How would that affect the kAIC rating of the unit?

Appreciate the help on this one.
Thanks,
EE
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
Can one use a 480V, 3 pole breaker on a 240V, 3 phase system?
I cannot remember ever seeing a 480V breaker that did not also have an AIC rating at 240V.
But yes you can, for non-utilization equipment, voltage ratings are maximums.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
We have used 480 and 277 volt CB's on 208Y/120 volt panels when the engineer specified a high 65 KAIC rating. Something like this:
65KAIC Circuit Breaker.jpg
 

brantmacga

Senior Member
Location
Georgia
Occupation
Electrical contractor
Yeh I’ve used NF PowerLogic 480 panelboards on 208Y/120 systems .


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