Neutral Wire

[papa smurf]

Does the neutral wire ever have voltage on it.

 

[iaov]

Only if opened or not bonded. In a properly installed system you might read a few milivolts to ground because of resistence in the wire. Any more than that and you have issues.

 

[wbalsam1]

Does the neutral wire ever have voltage on it.

the AC voltage on the "neutral" (grounded) conductor is zero with respect to earth ground :smile:
http://www.apcmedia.com/salestools/SADE-5TNQYQ_R0_EN.pdf

 

[Pierre C Belarge]

If you mean a "true neutral", it carries the imbalance between the energized conductors.

If you mean the white conductor of a two wire circuit, then yes it carries the same amount of current as the energized conductor.

If it is the grounded conductor of a 3-wire circuit that is installed from a 4-wire circuit, Wye system, then the grounded conductor will carry a substantial amount of current.

Take a look at 310.15(B)(4)

 

[ItsHot]

Does the neutral wire ever have voltage on it.

Usually when you didn't want it too!

 

[don_resqcapt19]

the AC voltage on the "neutral" (grounded) conductor is zero with respect to earth ground :smile:

That is true only for the neutral at the point where the main bonding jumper is located or for a neutral that is not carrying any current. All neutrals that carry current will have a voltage to earth that is equal to the voltage drop on the neutral conductor between the point of measurement and the main bonding jumper.

 

[raider1]

Does the neutral wire ever have voltage on it.

In relation to what?

The neutral wire in relationship to the EGC would have voltage of 0 or very nearly 0 depending on the voltage drop of the conductors.

The neutral wire in relationship to an ungrounded conductor would have a voltage equal to the system voltage.

Chris

 

[charlie]

Does the neutral wire ever have voltage on it.

Yes. There will be a potential from the current carrying neutral to the normally non-current carrying grounding conductor. The voltage drop will make the difference as well as the difference in sizes of conductors. As stated before, the voltage will be low but it will be there. It all depends on how much return current there is on the neutral and the other parameters.

 

[quogueelectric]

Yes it can have a few volts with reference to ground.
Depending upon its distance from the source and the load on the entire system it would not be unusual to measure 1,2 or 3 volts on a large commercial building with respect to ground from the neutral.
It is simply voltage drop due to a combination of the load and the resistance/length of the wire. This will also sometimes create a small spark/arc when you touch it to ground.
This used to mystify me when I was a first year apprentice in 84 and hardly anyone could answer correctly what caused the spark/arc.

 

[wbalsam1]

Yes it can have a few volts with reference to ground.
Depending upon its distance from the source and the load on the entire system it would not be unusual to measure 1,2 or 3 volts on a large commercial building with respect to ground from the neutral.
It is simply voltage drop due to a combination of the load and the resistance/length of the wire. This will also sometimes create a small spark/arc when you touch it to ground.
This used to mystify me when I was a first year apprentice in 84 and hardly anyone could answer correctly what caused the spark/arc.

If any body should be an expert on voltage, it should be a cow. They certainly have to put up with a lot from untrained farmers doing electrical work.