Understanding Circuit Breaker Terminals: IN & OUT Explained

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 2K views
Gabriel Samek
Messages
1
Reaction score
0
Why does a circuit breaker not show which terminal is IN and OUT?
 
Engineering news on Phys.org
Gabriel Samek said:
Why does a circuit breaker not show which terminal is IN and OUT?
Because it's irrelevant. Circuit breakers have no polarity. That is, there IS no "in" and "out". You can hook it up either way.
 
  • Like
Likes   Reactions: davenn
phinds said:
Because it's irrelevant. Circuit breakers have no polarity. That is, there IS no "in" and "out". You can hook it up either way.
For AC breakers, yes.

DC circuit breakers may have a polarity. Those that do oppose quenching and direct the arc into the switching mechanism rather than aid quenching, and point it into the arc chute when they are wired backwards.
 
  • Like
Likes   Reactions: Averagesupernova, berkeman and cnh1995