3Phase, how many single phase A

[aries]

Hello -

If I have a 120/208 3-Phase 200A service in a delta configuration. How many single phase 120V Amps can this accommodate and how would I calculate this?

Thanks
-J

 

[roger]

You can not have a 120/208 service in a Delta configuration.

Roger

 

[Volta]

Hello -

If I have a 120/208 3-Phase 200A service in a delta configuration. How many single phase 120V Amps can this accommodate and how would I calculate this?

Thanks
-J

You can not have a 120/208 service in a Delta configuration.

Roger

Of course, Roger is right, that doesn't exist as stated.

Is it the case that you are asking about a "high-leg" delta 240 volt system? That would provide 120 volts, 208 volts, and 240.

If so, you could use up to 200 amps @ 120 volts, twice.:smile:

Welcome to the forum.

 

[charlie b]

When dealing with three phase calculations, I always want to do the math in terms of power. Convert everything about your supply and your loads into units of KVA, do what you need to do, then convert back to amps. Some might say that engineers aren?t happy unless the process is complicated, or that we are suspicious about ?simple solutions.? I prefer to say that I want to know that the method I used is correct, rather than relying on unverifiable short cuts.

Let me answer your question with the modification that I will presume you meant 120/208 volt WYE. That will, at least, show you my method.

? At 120/208V, a 200 amp service is equivalent to 200 times 208 times the square root of three, or 72,050 VA.
? If you are serving only 120 volt circuits, then take 72,050 VA and divide by 120, and you get 600 amps.

OK, you could have simply taken 200 times 3 and been done with it, but would you have had confidence that that was the correct approach?

Welcome to the forum.

 

[aries]

You can not have a 120/208 service in a Delta configuration.

Roger

Roger -

Of course, you are correct. I was tired when I posted that. The configuation is Wye.

Thanks
-J

 

[aries]

When dealing with three phase calculations, I always want to do the math in terms of power. Convert everything about your supply and your loads into units of KVA, do what you need to do, then convert back to amps. Some might say that engineers aren?t happy unless the process is complicated, or that we are suspicious about ?simple solutions.? I prefer to say that I want to know that the method I used is correct, rather than relying on unverifiable short cuts.

Let me answer your question with the modification that I will presume you meant 120/208 volt WYE. That will, at least, show you my method.

? At 120/208V, a 200 amp service is equivalent to 200 times 208 times the square root of three, or 72,050 VA.
? If you are serving only 120 volt circuits, then take 72,050 VA and divide by 120, and you get 600 amps.

OK, you could have simply taken 200 times 3 and been done with it, but would you have had confidence that that was the correct approach?

Welcome to the forum.

Hi Charles -

Thank you very much for the answer, and more so the explanation. I am studying with the goal of becoming licensed and explanations such as yours are exactly what I was hoping I would find in this forum! Very helpful!

And, thanks for the welcome. I'll try to keep my simplistic questions to a minimum but I'm sure I will have a few more.

-J