After viewing the thread in the Mike Holt Forum named

What Is A Neutral...Again

located at http://www.mikeholt.com/forum/Forum1/HTML/003110.html

I wanted to poll members here and get some discussions going for the benifit of all members - new and legacy, from persons just entering the trade to persons retiring with 50+ years under their belt.

If we keep the thead "Flame Free" , we can really move forward.
This is why I brought the topic here to ECN - for a quality discussion with people that would rather discuss the topic in detail instead of flinging flames.

If this one takes off and covers the topic well, let's tackle some others!

I'll check back later and post something.

Scott S.E.T.

P.S. came back and editted the message so it looked a little better!
S.E.T.

[This message has been edited by Scott35 (edited 07-16-2002).]

I'll dare--

I don't consider a grounded conductor on a 2-wire secondary to be a neutral.
I don't consider the grounded phase conductor of a 3-phase, 3-wire, corner grounded delta system to be a neutral.

I do consider the following to be neutrals:
The grounded, 4th wire of any 3-phase, 4-wire, wye connected system.
The grounded, center-tapped conductor of a 3-phase, 4-wire, delta-connected system.(Although this one is debatable)
The grounded, 3rd wire of a center tapped single phase, 3-wire, (residential) system.
Let it fly!



[This message has been edited by Redsy (edited 07-16-2002).]

I've ben told that there's no such thing as a neutral in single phase, but someone needs to tell Square D that! (They have the grounded conductor lug marked "N")

Actually, I like Redsy's definitions.

I'll have to agree with Redsy, except for the 3Ø 4W Delta. The grounded conductor is not electrically equidistant from all of the phase conductors.

I guess my personal criteria for defining "neutral" is whether or not the grounded conductor will potentially carry no current on a balanced load. This is the case on "Edison-type" systems and on the grounded conductor of a "high-leg" system.
I also have heard the common connection point on wye connected systems referred to as the "neutral point".
Of course, this is only my take on the subject.

This is just one of those things where the technical definition and the common trade usage are never going to match. Maybe for the purposes of the code and the application of rules like 310.15(B)(4), we need a formal definition, but I would expect that most in the trade will continue to call all white wires neutrals.
An example of a definition that does not match the field usage of the word is the word "fitting". The field usage of the word fitting really means conduit body. Look at how the code defines this word. This even caught CMP 8. The code about 4 or 5 cycles back said that you can have no more than 360° of bend between fittings. That is not what the code really meant, but that is what it said. It was code legal, at that time, to have 360° of bend between each coupling at that time based on the code rule and the definition of fitting. Now the rules says between pull points not between couplings.
Don

I've been following that thread as well.

Common usage over here uses neutral even when referring to a 2-wire single-phase circuit. In fact, all of our receptacles and other accessories are marked "N" for the neutral/grounded conductor.

How about the term "common"?

IMHO,

The common conductor on 1Ø 3W 120/240V system or the 3Ø 4W 208/120V or the 3Ø 4W 480/277V or other similar systems where all conductors are being used on a circuit, ( not the 3Ø 4W 240V system ), the Grounded Conductor may be called the Neutral Conductor.

In all other senerios, 1Ø 2W circuit from a 1Ø 3W system, or a 2W or 3W circuit from the 4W systems noted above, the Grounded Conductor is the "Grounded Conductor".
Definitely not a neutral conductor.

And YES, I am occasionally guilty of calling the grounded conductor the neutral when I should not. Old habits are hard to stop.

I also have problems with the use of Grounding and Bonding terminology.

Glenn

There is no big sin in a little trade slang on the job, it however opens up wiggle room as applied to technical concerns.

Some jobs tend to create thier own brand of slang...

case in point, a somewhat err..'literary challenged' helper once wrote 'steak-ons' on a box holding sta-kons.
He later ran the box over....
thus 'hamburger-ons' became the norm, with all hands relating.

I've not seen too many delta 3Ø 4 wire systems carry a balanced load.

"Common"...

Heh heh!

Oooo Boy, that conjurs up some confusion...

I've seen neutrals connected to 3-Way switches (and a black wire connected to the ground screw once) when a homeowner tried to replace a 3-Way. The words "common" and "ground" sure confuse *some* auto mechanics...

Auto wiring gives me the heebee geebees... I hate troubleshooting vehicle electrical systems...

How about the term "floating neutral" Do you consider this correct?

Does "neutral" mean no potential to ground, or carrying no current under balanced conditions, or anything else?
electure,
Although the whole delta system would not be in balance, I believe the 2 lines with the center tap between them could be balanced with respect to one another, and therefore, the (neutral?) would carry no ccurrent.

BTW,
You union guys, what does the IBEW teach on this matter? I would put some stock on their take on the issue.

Oh yes! I've come across one or two auto people here like that. Really confusing when you start talking about something like an RV. Because the 12V auto side uses "ground", "earth", or whatever as one circuit conductor some of them seem to have great difficulty understanding that the AC power ground is really something quite different.

The definition for neutral conductor that makes the most sense to me, and which happens to be the Canadian Electrical Code definition -

"Neutral means that conductor(when one exists) of a polyphase circuit, or a single phase, 3-wire circuit, which is intended to have a voltage such that the voltage differences between it and each of the other conductors are approximately equal in magnitude and equally spaced in phase."

According to this definition-

1. The grounded conductor of any wye connected system, or center tapped single-phase system, is a neutral.

2. The grounded conductor of a 2-wire, single phase system is not a neutral. (I just think of it as a "return".


3. The grounded conductor of a 4-wire delta is only a neutral for phases A and C, but not for the high leg.

4. The grounded conductor of a corner grounded 3-wire delta system is not a neutral.

Ed

[This message has been edited by electric-ed (edited 07-20-2002).]

That one sounds good to me!
S

Looks like for electric-ed's posting, in 1. the definitions of neutral are consistent with NEC’s definition of being mutliwire circuits; whereas 2., 3. and 4. are not.

Bjarney, but they are correct.

As others have stated, there will always be slang or generic language used in everyday life.

If we use a screw driver to remove a knock out, do we change our norm and say hand me the K.O. removal tool?
And then expect someone to know what we are talking about.

Roger

Great responses, everyone!!! Glad to see so many different angles.

My $0.02:

Grounded Conductor suits me the best all around.

In lieu of that, I like to use these terms:

1 Ph. 3 wire systems: Center Tap, or Grounded Center Tap, along with Noodle,

3 Ph 4 wire Wye systems: Common, Common Conductor, Common Grounded Conductor, along with Noodle,

3 Ph. 3 wire Corner Grounded systems: Grounded Conductor, Grounded "Phase" [ewww!], Grounded Line, and even Noodle would work for me!

Thanks for the contributions!

Scott S.E.T.

Official definitions and common slang usage are often at odds with each other.

Over here, plugs and other wiring devices are typically marked with L, N, and E, which stand, officially for Line, Neutral, and Earth. But the average person almost always calls L the "live" wire or terminal, and it's common trade slang as well, something akin to your use of "hot."

The official IEE definition of "live" though is any conductor which carries current during the normal operation of the system. In other words, it includes a neutral/grounded conductor.