Breaker Ratings

[A-1Sparky]

Just wondering if each pole of a 3 pole 20 amp breaker is rated for 20 amps. Basically, can you have say, 17 amps on A phase, 18 amps on B phase, and 18 amps on C phase and not have the breaker trip on thermal overload? Or is it the combination of all 3 phases that's rated for 20 amps?

 

[iMuse97]

Just wondering if each pole of a 3 pole 20 amp breaker is rated for 20 amps. Basically, can you have say, 17 amps on A phase, 18 amps on B phase, and 18 amps on C phase and not have the breaker trip on thermal overload? Or is it the combination of all 3 phases that's rated for 20 amps?

What's your take on it? Its 20A on each, or why else could you take three 20A SP CBs and tie them together and achieve the equivalent of a 20A 3P CB?

 

[A-1Sparky]

What about a 2-pole single phase breaker?

 

[LarryFine]

Here's a hint: multi-pole breakers are usually two or three single-pole breakers with common-trip mechanisms added and the bodies riveted together. You get more power from the same current by having more than one line conductor.