3 phase and 1 phase loads, What is my capacity?

[iwire]

I don't see why amps per phase is such a terrible statement,

To me it suggests a DIY, a novice.

Stick with VA.

 

[fostachild]

To me it suggests a DIY, a novice.

Stick with VA.

Smart$ was correct to point out the terminology difference between line and phase, which I was mistakenly using interchangeably. That was a good response.

Yours was not. If it is industry standard to use VA, maybe just say that (or nothing since it has already been beat to death).

Thanks.

 

[charlie b]

I don't see why amps per phase is such a terrible statement. . . .

Because the word "per" means "for each," and that tends to make people want to add up the three phase to get a "total amps." That is, they will see "15 amps per phase" on Phases A, B, and C, and conclude (incorrectly) that the "total amps" is 45. What I am suggesting is that we should all avoid the "near occasion" of that error.

Besides I love me some matrix algebra and differential calculus. . . . Thanks again for the resources, and all of your help.

It that case, I will offer another resource. This is the textbook from my first class in my Masters Degree program on the topic of power systems analyses: William D. Stevenson, Jr., "Elements of Power System Analysis," McGraw-Hill. I have the fourth edition, copyright 1982. You can find it on line, but in a quick review I was not able to find a more current edition. Perhaps the one I have is, in fact, the most recent edition.

 

[Besoeker]

Because the word "per" means "for each," and that tends to make people want to add up the three phase to get a "total amps." That is, they will see "15 amps per phase" on Phases A, B, and C, and conclude (incorrectly) that the "total amps" is 45.

Would people really do that? I've known it to happen.
I think a better way to put it might be the current in each phase. Ultimately, it's the current carrying capacity of the conductors that limits the permissible maximum loading and, without jiggling the loads between phases, it's the most heavily loaded phase that's likely to determine that.