I need some help- circuit breaker question 6V vs 12V

[rotorwrench]

Originally Posted by mshmodela

V=IR, or I=V/R. 30A = 12V/R , divided both side by 2.

30A / 2 = 12V /(R x 2) = 15A = 6V / R where R is the resistance of the breaker. So a 30A, 12V breaker would pop with only 15A at 6V.

Amps are current draw or flow and volts are the carrier in a circuit. The theory applies to a circuit but the circuit protective device is largely only affected by current that flows through it. Voltage only affects it when it is a lot higher. If you look at most circuit protective devices, they have the current and maximum voltage printed on them. Cheap automatic reset breakers made in third world counties may not though.

In aviation, we use the same manual reset type breakers for both 12 and 24-volt systems since they are both below 32-volts DC. There is no difference.

This is an old thread.