2 phase

[brian john]

DDEPUY:

The only place I saw 2 phase was downtown Philly (old old building) always wondered about the transformer connections. Anybody have a link to s 2 phase xmfr drawing?

http://www.3phasepower.org/2phasesystems.htm

 

[Dave_PE]

That's were my 2-phase project was that I worked on.....it was in Andora, just out side Philly, in an old shopping center. I basically looked at it as two parallel single phase services. I had a 400A, 4-pole main which fed a gutter, where I tapped two, 200A, 2-pole disconnects to feed two single phase panels.

 

[zgozvrm]

Different Systems

Different Systems

could anyone tell me the calculation to covert 2 phase amps to watts

I wasn't aware that there were two types of 2-phase systems in use. One is a 4-wire system that apparently is NOT inter-connected. The other is a 3-wire system which uses a common (not neutral) conductor.

So, I guess it comes down to not only which system you're referring to, but also (with the 3-wire system) how you're measuring your voltage: line-to-line or line to common.

 

[rattus]

Question?

Question?

Does any 2-phase system utilize the phase to phase voltage? For example, in a 3-wire, 120V system, this voltage would be 170Vrms. Not that we will ever encounter such an animal.

 

[jim dungar]

Does any 2-phase system utilize the phase to phase voltage? For example, in a 3-wire, 120V system, this voltage would be 170Vrms. Not that we will ever encounter such an animal.

Actually most 2-phase systems use only the P-P voltage which is typically 240V. The advantage of a 2PH 3W is one fewer conductor, although the common (not neutral) conductor needs to be 1.414 the size of the other conductors.

There is a hybrid 5-wire system that uses the center taps of each phase winding to provide a usable 120V P-N.

So as far as the original OP question, the formula is kind of dependent on what your voltage reference is, but this is really no different than we have with 3-phase systems.

 

[Smart $]

I wasn't aware that there were two types of 2-phase systems in use. One is a 4-wire system that apparently is NOT inter-connected. The other is a 3-wire system which uses a common (not neutral) conductor.

So, I guess it comes down to not only which system you're referring to, but also (with the 3-wire system) how you're measuring your voltage: line-to-line or line to common.

According to the American Electrician's Handbook, there were three types of two-phase systems:

 

[Smart $]

Does any 2-phase system utilize the phase to phase voltage? For example, in a 3-wire, 120V system, this voltage would be 170Vrms. Not that we will ever encounter such an animal.

I believe motors utilize(d) phase to phase voltages of a 5-wire system.

(Courtesy of the American Electrician's Handbook)