Dear all,
I'm looking at a 3-phase, 12-wire generator for single phase operation, and trying to make sense of how the potential wiring configurations differ and the math behind how they produce the "split-phase" voltage. As I see it, I have two options that will produce 120/240 volts (assuming each stator is producing 120V):
1) double delta
2) parallel zig zag
Attached to this post are two pictures, one which show the 6 stators and 12 wires on the generator (each wire labeled from 1 through 12), and the other which shows the wiring configurations for both options mentioned above. These are both taken from the generator user manual.
I understand how the double delta produces the 120/240 volts because line 1 (wire #4) and line 2 (wire #1) come from stators on the same phase (same as they would be in one side of a series delta configuration) so adding the output from two 120V stators, both on the same phase, gives 240V. And placing the neutral wire in between them means 120V from line to neutral for each.
But the parallel zig zag leaves me perplexed...I understand the 120V from the line on the right side (wires #1 and #3) to neutral, but not A) how you get 240V from line to line, or B) how you get 120V from the line on the left side (wires #7 and #5) to neutral.
For A) it seems that you would get the same output as line to line in a parallel star configuration: 208V, since they are 120 degrees out of phase. For B) it seems you might get double that, or 416V, since you have two different phases but also opposite "ends" of the stators.
I think its pretty safe to assume that the generator manufacturer (Mecc Alte) knows what they are talking about, and it seems to be well-established that parallel zig zag will produce the same 120/240V output as double delta, but I can't seem to make heads or tails of WHY.
Can someone please help on how this actually works?
Thanks!
Ben
I'm looking at a 3-phase, 12-wire generator for single phase operation, and trying to make sense of how the potential wiring configurations differ and the math behind how they produce the "split-phase" voltage. As I see it, I have two options that will produce 120/240 volts (assuming each stator is producing 120V):
1) double delta
2) parallel zig zag
Attached to this post are two pictures, one which show the 6 stators and 12 wires on the generator (each wire labeled from 1 through 12), and the other which shows the wiring configurations for both options mentioned above. These are both taken from the generator user manual.
I understand how the double delta produces the 120/240 volts because line 1 (wire #4) and line 2 (wire #1) come from stators on the same phase (same as they would be in one side of a series delta configuration) so adding the output from two 120V stators, both on the same phase, gives 240V. And placing the neutral wire in between them means 120V from line to neutral for each.
But the parallel zig zag leaves me perplexed...I understand the 120V from the line on the right side (wires #1 and #3) to neutral, but not A) how you get 240V from line to line, or B) how you get 120V from the line on the left side (wires #7 and #5) to neutral.
For A) it seems that you would get the same output as line to line in a parallel star configuration: 208V, since they are 120 degrees out of phase. For B) it seems you might get double that, or 416V, since you have two different phases but also opposite "ends" of the stators.
I think its pretty safe to assume that the generator manufacturer (Mecc Alte) knows what they are talking about, and it seems to be well-established that parallel zig zag will produce the same 120/240V output as double delta, but I can't seem to make heads or tails of WHY.
Can someone please help on how this actually works?
Thanks!
Ben
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