Resistive and capacitive loads are in relation to whether the current or voltage is leading or lagging in the phase angle. Tnis can affect the power factor and play a part in harmonic distortion. The nuetral does not care what type of load you have when it is being shared as long as the ungrounded conductors are on opposing phases.

While I fully agree with the over / under voltage conditions well illustrated when there exists an open circuit neutral conductor, the problem remains in that this situation is not cleared by common trip breakers. In the illustration, neither branch will draw suffient current to trip either breaker. Actually we then have a single series circuit connected to a 240 volt supply, with both devices carrying the same current. The voltage drops remain as illustrated until something burns out! This could not be resolved by a pair of GFCI breakers, since they would need neutral conductors that are serarate for each branch circuit. They require balanced current in their line and neutral conductors.

Not strictly related, but a question about multiwire circuits. On a normal three-wire circuit, say 12-3 NMB on a two-pole 20A breaker, each leg could be drawing 20A line-to-neutral without opening the breaker. That would mean 40A on the neutral leg, way too much for 12-gauge, except that the currents, being 180° out-of-phase, cancel on the neutral.

That's really true only if the loads have the same reactance -- zero, for example, if they're both only resistive. What if I run a capacitor-start motor on one leg and a transformer on the other? Couldn't I then exceed 20A on the neutral? And wouldn't that be hazardous? What am I missing here?

Thanks.

Thanks to to your great color pictures, I use them at the Adult Edu. center for the LAUSD Home Repair classes.

Not strictly related, but a question about multiwire circuits. On a normal three-wire circuit, say 12-3 NMB on a two-pole 20A breaker, each leg could be drawing 20A line-to-neutral without opening the breaker. That would mean 40A on the neutral leg, way too much for 12-gauge, except that the currents, being 180° out-of-phase, cancel on the neutral.

That's really true only if the loads have the same reactance -- zero, for example, if they're both only resistive. What if I run a capacitor-start motor on one leg and a transformer on the other? Couldn't I then exceed 20A on the neutral? And wouldn't that be hazardous? What am I missing here?

Thanks.