5 wire, 2 phase

[BKDog]

I apologize for not being able to remember where this question comes from but does anyone have any experience with a "5 wire, 2 phase" installation? I am unable to find an illustration of this. Is this "double 2 phase"? Parallel neutrals would still be a 4 wire system, right?

 

[drbond24]

http://www.mikeholt.com/forum/Forum1/HTML/005278.html

http://forums.mikeholt.com/showthread.php?t=53674

 

[BKDog]

so I actually have 2 sets of "2 phase"
would this be supplying 2 separate panels? what would the voltage be between legs? can I figure this with an RMS formula? Any idea what the application be?

Thanks for your time guys

 

[jim dungar]

so I actually have 2 sets of "2 phase"
would this be supplying 2 separate panels? what would the voltage be between legs? can I figure this with an RMS formula? Any idea what the application be?

Thanks for your time guys

You need to explain what you are trying to accomplish. Is this mental gymnastics or do you have a real world application?

2-phase is an archaic, and rare, system that was primarily used in heavy industry. Yes, a true 5-wire system is actually two 2-phase systems which share a common reference point. There was no practical connection between the phase conductors of the different systems, and also in fact, the were few practical reasons to use a phase-common conductor voltage in any 2-phase system.

 

[electricalperson]

the electricians handbook talks about 2 phase systems. although its interesting to learn about and see, you probably will never actually work on them since they are obsolete. i dont even know if power companies supply 2 phase power anymore. only place where you will see 2 phase is very old factories. how many old factories are around now?

 

[rattus]

I apologize for not being able to remember where this question comes from but does anyone have any experience with a "5 wire, 2 phase" installation? I am unable to find an illustration of this. Is this "double 2 phase"? Parallel neutrals would still be a 4 wire system, right?

This system has been described by some authors as a 4-phase system, but it is derived from a single 2-phase system by connecting the CTs of the 2-phase secondaries. The common CTs form the 5th wire--the neutral.

 

[quogueelectric]

There used to be an old system which had 2 phases 90 degrees out of phase to create rotating field. It was all but extinct when I switched to commercial in 1984. It was still around on some state run facilities and was being PHASED OUT. I dont know of any in existance now though.

 

[LarryFine]

It was still around on some state run facilities and was being PHASED OUT.

Very punny!