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#127547 08/22/01 08:43 PM
Joined: Aug 2001
Posts: 545
aldav53 Offline OP
When measuring each leg on a 3 phase service, if it is a 200amp panel and the feeder wire is good for 200 amps, that would mean each leg is good for 200amps measuring individually with an amp clamp. Is this correct? If it is, does that mean you have a total of 600 amps?, or is that just the relationship between the phasing in the transformer, and actually only have a 200amp total.
Hope this makes sense..

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#127548 08/22/01 08:57 PM
Joined: Dec 2000
Posts: 4,294
If you have a 208 volt system, you'll have 72051 voltamps available. If it's a 120/208 system, you will have a total of 600 amps of 120 volt power available.
If a 480 system you'll have 166272 voltamps available. If a 277/480 system this will give you a total of 600 amps of 277

#127549 08/22/01 09:25 PM
Joined: Mar 2001
Posts: 2,056
Electures explanation is a good one. I like to keep it simple - the conventional definition is a 3 phase 200 amp service. Total available (apparent) power = V x A x 1.73

[This message has been edited by Redsy (edited 08-22-2001).]

#127550 08/22/01 09:54 PM
Note: 1.73 is really the square root of 3.

#127551 08/24/01 06:34 AM
Joined: Jul 2001
Posts: 311
"If it is, does that mean you have a total of 600 amps"? My question is: Wouldn't there actually be 600 amps available for example if all loads were 120 volts, line to neutral? I know it would not be practical. However, wouldn't it be possible?

#127552 08/24/01 06:41 AM
Joined: Jul 2001
Posts: 311
I forgot to mention in my above example the service is: 120/208V, 3Ph, 4W, 200 amps.

#127553 08/24/01 08:22 AM
Joined: Mar 2001
Posts: 2,056
I still say no. It would be a balanced 3 phase 200 amp load, equally divided between the phases at 200 amps each. However, you could supply 20 10 amp 120 volt loads on each leg. This would translate 600 a. x 120 v. which puts you back to 72,000 watts.

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