Virgil,
Exactly! If there was Two separate Phasors [Sinewaves will also apply] which were 180 degrees apart, they would nullify, or cancel each other out - similar to bouncing a sound wave with an echo of it's own, but at 180 degree phase shift - it will cancel the original sound wave out. This technique is used in Industrial Noise control.
Put two single coil pickups in an 180 phase shift [in parallel], and you have practically no volume, plus that "out of phase" sound.
The Neutral balancing currents for 1 phase 3 wire systems works mainly because the magnetic flow in the core will drive fully across the entire coil in an equal strength.
Where there's an imbalanced current, the magnetic flow in the core will have a higher level from the side of the core which the "Line" with the higher current load is wound from, then to the center of the core.
This occurs when the secondary circuits draw currents from the windings, which changes the stablized level of magnetic flow in the core. The Primary tries to re-establish that steady level in the core by producing more and more flux flowing in the core, until things become stable again.
Easy way to picture the magnetic flow which creates the imbalanced current is to think of only drawing a load from L1 and the Neutral, with no load on L2 and the Neutral.
The magnetic flow in the core will circle around the part of the winding which makeup the L1 and Neutral circuit with a high intensity.
This equals out to have an electrical circuitry setup which is a series current flow with balanced loads, but parallel with the imbalanced portions of loads.
If the loads are equal, they will naturally run in series with the L1 - L2 conductors, simply because it's easier for larger currents to flow this way [easier to drive full current levels through the entire coil].
Any currents which are uncommon to other currents flowing, will be run through the center tap. This would be very common for Harmonic currents and EMI / RFI.
Along with these currents, the currents needed to charge circuits will flow through all taps - regardless if the loads are only across L1-L2 [240 VAC]. There will still be circulation of currents and charging currents on the center tap.
Scott SET
