We had a lively discussion at work yesterday and I'd like some comments from this forum on the subject.
Suppose I have a service from a Y-connected 3ph-208/120VAC 200amp panel protected by 200amp fuses. I use a standard Amprobe to measure each leg of the panel feeder wires
and it reads 150 amps. Does this mean there is also 150 amps phase-to-phase flowing thru
each fuse, or is it less than that?
One fellow was saying that measuremening the current on one leg will be significantly
higher than what is flowing through the entire system, because of the characteristics of 3ph transformers (vectors, phase angles, etc.) In other words, an ammeter can indicate that the panel's load is more than 200 amps and still not blow fuses. I'd appreciate your input on this.
Thanks
