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3 phase total power #127547
08/22/01 08:43 PM
08/22/01 08:43 PM
A
aldav53  Offline OP
Member
Joined: Aug 2001
Posts: 545
Chandler, AZ USA
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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Re: 3 phase total power #127548
08/22/01 08:57 PM
08/22/01 08:57 PM
electure  Offline

Member
Joined: Dec 2000
Posts: 4,274
Fullerton, CA USA
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

Re: 3 phase total power #127549
08/22/01 09:25 PM
08/22/01 09:25 PM
R
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
Bucks County PA
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).]

Re: 3 phase total power #127550
08/22/01 09:54 PM
08/22/01 09:54 PM
A
Anonymous
Unregistered

Note: 1.73 is really the square root of 3.

Re: 3 phase total power #127551
08/24/01 06:34 AM
08/24/01 06:34 AM
F
Frank Cinker  Offline
Member
Joined: Jul 2001
Posts: 311
Pennsylvania
"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?

Re: 3 phase total power #127552
08/24/01 06:41 AM
08/24/01 06:41 AM
F
Frank Cinker  Offline
Member
Joined: Jul 2001
Posts: 311
Pennsylvania
I forgot to mention in my above example the service is: 120/208V, 3Ph, 4W, 200 amps.

Re: 3 phase total power #127553
08/24/01 08:22 AM
08/24/01 08:22 AM
R
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
Bucks County PA
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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