I'm alergic to that white stuff, makes me start to shake and shivver. Blimey, that's why I live herre I guess.
I'm having a hard time seeing any real difference between the 120V components of a 120/240 delta service and a resi service right next door that's taken off the same primary. In the resi you just have some missing components (the other 2 transformers). Kind of a new definition of a really really open delta.
Let's back up a little and change the original situation just a little. Supposing we had 34KVA on ØA and the same on ØC (instead of 41KVA). That would essentially equate to 68KVA across a 240V potential and render the neutral connection an anchor or ground reference point without any current. Current would flow in A and out C, or visa versa at any given instant of time, neutral current would be zero, A-C current would be 284 amps.
I'm still seeing a single 240V potential between 2 points (ØA & ØC) with a grounded center point, nothing more. You've got a single transformer secondary we're dealing with here, the other transformers connected to L2 (ØB) are of no consequence to the 120/240 part of this. IFF (that's if and only if) any of the 120V current also flowed thru the other transformers to L2 (B), then we'd have phase angles and some trig to work out, but that's not the case. All 120V current flow is limited to the one transformer secondary between L1 & L2. We're splitting that in half, so it appears to be a 180º split.
True enough the three phase currents are flowing all around the transformer connections following the 3 distinct sine waves, but the single phase 120/240 leg is not a split phase, it's just 240 volts.
It's getting late (even here), so maybe we'll just agree to disagree. But I will think about it some more.
Take care, my friend. Don't freeze out there tomorrow (eheh - take lots of warm up breaks). Sorry this got longer than I had intended.
Radar
