Brian,
thanks, like I said in post #300 that Sewerzuk's mod is in between 120 single and 120/208 single but it's really neither one.
The problem comes from the fact that Sewezuk had moved T2 H2, J9 M, X8HH from T8 to T11 which is neutral - he had left T2 H1, J9 L, (forgot wire number) on L3
He had disconnect the end of the L3 coil system from neutral and that changed the setup from WYE configuration to something you cannot find in any text book and connected the end of L3 coil to L2 which is now not used (floating)
With no load, this system will have somewhere from 120 to 208 VAC to Neutral on L3 - hence T2 will work for a while until the load on L3 changes and has to flow now through L2
Connecting T2 H2, J9 M, X8HH to T7 will connect it to L1 - now T2 is between L3 / L1 which should have stable 208VAC voltage. You can see this kind of cycling when your trying to synchronize two parallel Genset's incorrectly
A 240VAC single phase is 180 degrees out of phase - in Sewezuk's mod it could be anywhere from 120 degrees to 240 degrees, depending on how and how much load is connected
This whole thing may work, but this system is anything but stable.
Furthermore, one issue no one has ever mentioned in any of those mod posts is the Governor Load Measurement Unit A8
Even though not used in the utility version, but it is still installed in all 004A/005A's and connected as shown below........
You can imagine of what may happen if you apply 208VAC instead of the 120VAC on the primary of A8 T1...
The best thing is to disconnect all wires from A8 T1 on the reconnection board
View attachment 776550
The Voltage on F1/F2 is neither DC or AC - it is switched from your VR - If you indeed have 3 VDC on it and VR puts out 48VDC then you would get
U/R = I
3V / 2.2 Ohm = 1.36 Amps
48V / 12.2 Ohm = 3.93 Amps ( 12.2 Ohm = Coil 2.2 Ohm + R1 10 Ohm )
3.93 Amps would blow your 3 Amp Fuse, never mind a 1 Amp Fuse - it's switched DC
So, the only way to check F1/F2 is with an oscilloscope, but you can use the 3 VDC as a good reference for trouble shooting.
It would be interesting to see what a VAC measurement would yield on F1/F2
both of those measurements combined will make a great reference when trouble shooting a excitation system