Originally Posted by Jim18655
This is wrong! Each half of the breaker is capable of 50 amps of current. It is NOT measuring 50 amps total for the circuit.
Ummmmmm...... Yes it is.
The ganged breakers each control one "line" of a 240 VAC circuit. The 2 lines are 180 degrees out of phase as has been explained multiple times in this thread and on this forum. In a strictly 240 VAC circuit the current will be the same on both lines and the maximum is 50 amps. If you want to look at it instantaneously: as current leaves one breaker to the load it is coming from the load to the other breaker.
However, when you use the neutral to "split" the 240 VAC into two 120 VAC circuits you could have different currents on the two lines, but neither line can exceed 50 amps. If you have unbalanced loads, say 20 amps on line 1 and 30 amps on line 2, the neutral will carry the difference; but in no case will the neutral ever carry more than 50 amps.
Many people think of this system as two 50 amp circuits for a total of 100 amps, but that is at 120 VAC which is the same power as one 50 amp, 240 VAC circuit.