Hi,

I've a GE 120/240V 20A circuit breaker. I know most circuit breakers trip when the rated current is exceeded in the circuit. BUt lets just assume that the current in the circuit is drawing current less than 20A but the voltage rises to 380V. What will happen? Will the breaker trip or the whole circuit will burn down? I've seen breakers trip during lightning strikes, but thats mainly dues to large amount of volts and current.
Thank You.

 

Breakers respond only to current, not voltage.
So if a breaker trips during an overvoltage, it's due to the overvoltage causing an overcurrent.

 

Most of those a thermal based type, so as said, if the energy is sufficient to cause enough thermal energy then it trips.
Max.

 

Most modern household breakers are Thermal-Magnetic so the 'trip' point is not a linear factor of just current. There is a instantaneous magnetic trip and heat associated time characteristics.


http://static.schneider-electric.us/docs/Circuit Protection/Molded Case Circuit Breakers/0100-400 A Frame FA-LA/FA-FC-FH/0600DB0105.pdf

 

Thanks everyone. So, its only a current based device. I'm going to upgrade my panel and wiring with the latest breakers with GFCI. It was just curious to know if my breaker trips during a lightning strike, then will it trip during an over voltage spike too.