Proper Terminology

Little Bill

Little Bill

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What is the proper name/terminology for the ungrounded conductors in a single phase120V/240V service? A guy is trying to call each undrounded conductor as a phase. I just use "leg" in describing one of the conductors. He is saying that "leg" is a made up term and phase is the correct term. He is saying there are two phase brought in, with a grounded conductor, and each ungrounded conductor is a phase.
240V is brought in from a center tapped transformer. I don't see how each end of the transformer is a separate phase.

I'm not saying that leg is the correct term, but phase certainly isn't IMO.
 
Little Bill said:
What is the proper name/terminology for the ungrounded conductors in a single phase120V/240V service? A guy is trying to call each undrounded conductor as a phase. I just use "leg" in describing one of the conductors. He is saying that "leg" is a made up term and phase is the correct term. He is saying there are two phase brought in, with a grounded conductor, and each ungrounded conductor is a phase.
240V is brought in from a center tapped transformer. I don't see how each end of the transformer is a separate phase.

I'm not saying that leg is the correct term, but phase certainly isn't IMO.
Click to expand...
I use "leg" for single phase and "Phase" for three phase
 
infinity said:
What Roger said.

Definitely not phase for a 120/240 volt system because there is only one phase but there are two legs.
Click to expand...

Yes, it is only single phase. It's sometimes called split-phase because it's delivered with a center-tapped transformer that provides two legs of opposite polarity.
 
I've seen the term "phase" (in quotes) denoting a term that many will understand but that isn't really correct.
 
Per the NEC, 'ungrounded' conductor (as @rambojoe says).

The problem is that phase has multiple meanings, one is the 'ungrounded conductors supplying current to the load' and the other is 'the number of different supply phase angles'.

A single phase system only has one supply phase angle (with its inverse), but has two ungrounded conductors supplying current to the load.

A three phase system has 3 supply phase angles and has 3 ungrounded conductors supplying current to the load.

'Two phase' has a very well defined meaning of two _different_ supply phase angles, but may have 2 or 4 ungrounded conductors supplying current to the load.

Calling the two ungrounded conductors of a single phase system 'two phases' is confusing because it conflates the single phase system with a two phase system in a way that isn't a problem for three phases.

That is why it is common to call the ungrounded conductors 'legs' in a single phase system.

If I really wanted to be obtuse, I'd say a single phase system has two 'hemiphase' conductors. (Unless it was 120/208 psingle phase, in which case they really are two phase conductors :) ) Then 2 phase 2 wire has two phase conductors, and 2 phase 4 wire has 4 'hemiphase' conductors, and so called 'hexaphase' is really 3 phase 6 wire with six hemiphase conductors. But since 'hemiphase' showed up in literature a couple of decades ago and isn't really popular, I'd only do this to be annoying.
 
Using single words to describe items can lead to a lot of confusion.
It would propably be better to call it a "phase conductor". My preference is to call it a 'Line' or 'Hot'.

FWIW I was taught to use the number of Line/Hot voltages when counting the number of phases.
 
Little Bill said:
What is the proper name/terminology for the ungrounded conductors in a single phase120V/240V service? A guy is trying to call each undrounded conductor as a phase. I just use "leg" in describing one of the conductors. He is saying that "leg" is a made up term and phase is the correct term. He is saying there are two phase brought in, with a grounded conductor, and each ungrounded conductor is a phase.
240V is brought in from a center tapped transformer. I don't see how each end of the transformer is a separate phase.

I'm not saying that leg is the correct term, but phase certainly isn't IMO.
Click to expand...
I’ve always used the term “leg” in single phase and the two legs are 180 degrees out of polarity , they can’t be out of phase with eachother because there is only 1 phase, they may appear out of phase if your point of reference is the center tap , but the coil at the source is wound in one direction each end is 180 degrees opposite polarity
 
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