Grounded Conductor and Neutral

Status
Not open for further replies.
tom baker

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Article 200 is Use and Identification of the Grounded Conductor.
Most of us call the grounded conductor the neutral, and the 2008 NEC added a definition of a neutral.
Now its possible this falls under Charlies Law, and I am missing it.
But where does the NEC tell us a neutral is a grounded conductor?
The neutral is connected to the neutral point (definition) and then if we go to 250.20 we would work out that this point is "grounded", so it can be considered the grounded conductor.

But a grounded conductor is not always a neutral, IE for a 120V branch circuit

The 2011 NEC added 200.4, a requirement for a Neutral Conductor, but its still not clear that the neutral is a grounded conductor.

My proposal:
Add information note: See Article 100 Definitions for Neutral Conductor and Neutral Point.
Add information note: The neutral conductor is also a grounded conductor. A grounded conductor is not always as neutral conductor, for example a 4-wire, delta-connected system where the mid-point of one phase winding is grounded is not a neutral.
 
tom baker said:
Article 200 is Use and Identification of the Grounded Conductor.
Most of us call the grounded conductor the neutral, and the 2008 NEC added a definition of a neutral.
Now its possible this falls under Charlies Law, and I am missing it.
But where does the NEC tell us a neutral is a grounded conductor?
The neutral is connected to the neutral point (definition) and then if we go to 250.20 we would work out that this point is "grounded", so it can be considered the grounded conductor.

But a grounded conductor is not always a neutral, IE for a 120V branch circuit

The 2011 NEC added 200.4, a requirement for a Neutral Conductor, but its still not clear that the neutral is a grounded conductor.

My proposal:
Add information note: See Article 100 Definitions for Neutral Conductor and Neutral Point.
Add information note: The neutral conductor is also a grounded conductor. A grounded conductor is not always as neutral conductor, for example a 4-wire, delta-connected system where the mid-point of one phase winding is grounded is not a neutral.
Click to expand...

Where are you proposing to add these informational notes?

The example in your second informational note of the mid point of one phase of a 4 wire delta is already covered in the 2008 definitions of neutral point and the FPN after it also adds some clarification.

A grounded conductor is not always a neutral conductor. Like a grounded phase conductor on a grounded phase system, a high impedance neutral on that type of system is not a grounded conductor on the load side of the impedance device, and grounded circuit conductor on a two wire source is not a neutral.

A neutral conductor for the most part should be a grounded conductor once you apply 250.20 like you said.

If a neutral has a definition in Art 100, I don't see how 2011 200.4 fits into this discussion.

Appears the definitions remained same in 2011 as 2008.
 
Add to 200.1 as a second informational note.
Or maybe not.
Sometimes when I think its a good proposal, after its made I go what was I thinking.
There just needs to be some clear language somewhere that a neutral is a grounded conductor.
 
My proposal is add the following to 200. Scope
Informational Note No. 2: See 250.26 for when a grounded conductor is a neutral conductor.

Reason- there is not a direct and obvious connection to when a grounded conductor is a neutral. I also am making a companion proposal for 250.26 to change common to neutral.
 
Status
Not open for further replies.
Top