turbodog
Flashaholic
I have been thinking about this for a while. While laying a power cable to my shed today I though a good deal about it.
I ran a wire to my shed today for power out there. The wire was 10/3 w/ ground. So I have 2 hot conductors, 1 neutral, and 1 bare ground in a nice sheath designed for underground burial.
Now, all the wires appear to be 10 gauge in size. And 10 gauge is rated for (I think) 30 amps. The 30 is really immaterial anyway for my question. For now, let's just say 30.
This wire was hooked to my outside breaker panel with the hots going to a double pole breaker and the neutral and ground going the the grounding bus.
In my shed, I just have two circuits. One is from 1 hot (say black) and neutral (white). The other is from the other hot (red) and the SAME neutral (white). Ground is properly used.
Now, when I use circuit 1 and load it to 30 amps, the black and white wires are carrying 30A apiece. At this time, no load is on circuit 2.
Now, the reverse works the same, load 2 to 30A. Red and white are carrying 30A each.
But, when I load 1 and 2 to 30A... I used to think the neutral (common to BOTH) was carrying 60A, while black and red carried 30A each. This didn't make sense in that the white conductor was the same physical size as black/red. If this was true, either white was being pushed way beyond rated specs or black/red were oversized.
Then it hit me... black and red are out of phase by 180 degrees. So..... the neutral conductor's amperage is really the difference of the black and red load amperage.
Anyone that KNOWS for sure care to comment?
I ran a wire to my shed today for power out there. The wire was 10/3 w/ ground. So I have 2 hot conductors, 1 neutral, and 1 bare ground in a nice sheath designed for underground burial.
Now, all the wires appear to be 10 gauge in size. And 10 gauge is rated for (I think) 30 amps. The 30 is really immaterial anyway for my question. For now, let's just say 30.
This wire was hooked to my outside breaker panel with the hots going to a double pole breaker and the neutral and ground going the the grounding bus.
In my shed, I just have two circuits. One is from 1 hot (say black) and neutral (white). The other is from the other hot (red) and the SAME neutral (white). Ground is properly used.
Now, when I use circuit 1 and load it to 30 amps, the black and white wires are carrying 30A apiece. At this time, no load is on circuit 2.
Now, the reverse works the same, load 2 to 30A. Red and white are carrying 30A each.
But, when I load 1 and 2 to 30A... I used to think the neutral (common to BOTH) was carrying 60A, while black and red carried 30A each. This didn't make sense in that the white conductor was the same physical size as black/red. If this was true, either white was being pushed way beyond rated specs or black/red were oversized.
Then it hit me... black and red are out of phase by 180 degrees. So..... the neutral conductor's amperage is really the difference of the black and red load amperage.
Anyone that KNOWS for sure care to comment?