Distribution panel neutral/ground separation question

[Joshua L. Frederick]

Need some help understanding something.

Since the whole idea of the separation is that its possible for current to follow a parallel path -- over the bare grounding wires -- instead of the insulated neutral wires -- as it finds its way back to the source, which can present the hazard. Right? Now, at yesterday's inspection all of the outlets were 2-prong, not one grounded or 3-prong outlet. Would the distribution panel still need to be separated? Would it matter? Thanks for all replies, and your time is appreciated!

[Jeffrey R. Pope]

Yes, although the term "separated" may cause a bit of confusion. The term should be "isolated" or "ungrounded" at the distribution panel.

The distribution panel must be bonded to the service equipment, which essentially means that it is grounded. If the neutrals are not isolated, they become "grounded" at the distribution panel which (as we know) is improper.

[David A. Andersen]

I was trying to explain this the other day to a client...

Mr. Pope can correct me if I'm wrong (I consider him the expert).

You can connect neutral and ground at the Main service panel because that is the "junction point" where electrical service enters the house. Anything downstream of the main service panel has junctions which may become loose or inadequately connected allowing current to flow back into the neutral, rather than the ground due to inadequate path of least resistance to ground.

There is only one point of connection in the Main service panel for each component. Once you extend the electrical conductors to subsequent service panel's, you increase the potential of increased resistance which may cause electrical failure to back feed on a path of least resistance to a non-desirable location.

The main service panel has two legs of power, one neutral to the transformer, one grounded electrical conductor (to a grounding rod, hopefully below the meter box), one grounded electrical conductor back to the main transformer feed, and possible other connections depending on design.

Any interpretation that electrical current does not flow on neutral lines is a fallacy! It will in fact get you killed! Neutral wires are not on the same level as ground wires. They do carry electrical current where as ground wires do not. If you have an electrical failure which causes current to flow back onto the grounding system, you want the least path of resistance to be on the grounding conductors rather than the neutral.

Neutral wiring carries electrical current, therefore reducing its capacity to provide a line of least resistance back to earth where the electrical current does not cause physical injury. Grounding conductors should never be considered "the same as " neutral conductors.

[Paul W. Abernathy]

Your last sentence is incorrect in it's nature in some parts.....

You stated:

Neutral wiring carries electrical current, therefore reducing its capacity to provide a line of least resistance back to earth where the electrical current does not cause physical injury. Grounding conductors should never be considered "the same as " neutral conductors.

Remember...electrical current on a neutral is NEVER trying to get to the earth...it is trying to get to the source of it's creation and nothing more. If the earth is presented as a path it will travel on all paths...not just the path of least resistance. However, since the earth is such a high path of impedence it is not considered a good path nor is it ever an allowed path. Neutral conductors always carry current....grounding conductors only carry current under an abnormal condition for the most part so they should never be confused.

[Bob Elliott]

Originally Posted by pabernathy

Your last sentence is incorrect in it's nature in some parts.....

You stated:

Remember...electrical current on a neutral is NEVER trying to get to the earth...it is trying to get to the source of it's creation and nothing more. If the earth is presented as a path it will travel on all paths...not just the path of least resistance. However, since the earth is such a high path of impedence it is not considered a good path nor is it ever an allowed path. Neutral conductors always carry current....grounding conductors only carry current under an abnormal condition for the most part so they should never be confused.

Paul when you say Neutral conductors always carry current, you meant when under load?

[Patrick Bolliger]

Originally Posted by belliott

Paul when you say Neutral conductors always carry current, you meant when under load?

Yes Bob...when there is a load. Be it light, motor or toaster...or Bob

Hot wire------> Load<--------"neutral" wire
"Watts"

Now lets place Bob as the "load" Hot wire-----> "bob load"<---"neutral" wire.... ZZZAAAP!


OUCH! Notice the smoke from Bobs...shirt collar...

[Bob Elliott]

Originally Posted by pbolliger

Yes Bob...when there is a load. Be it light, motor or toaster...or Bob

Hot wire------> Load<--------"neutral" wire
"Watts"

Now lets place Bob as the "load" Hot wire-----> "bob load"<---"neutral" wire.... ZZZAAAP!


OUCH! Notice the smoke from Bobs...shirt collar...

Thank You Paul.
You sure have gotten violent since you changed your name.

[Patrick Bolliger]

I like the "hands on" approach.. we can experiment at the next meeting..
I will bring the wires and you can hold them

[Buck Hartley, CMI]

Is the proper way to do the separation? This was found in the main panel today. House is new, never been lived in. The local inspector, told the builder to remove this ground bar.

[Patrick Bolliger]

Originally Posted by bhartley

Is the proper way to do the separation? This was found in the main panel today. House is new, never been lived in. The local inspector, told the builder to remove this ground bar.

Buck,
That piece of copper is used to "bond" the panel to the neutral buss. Known as panel bonding.

If that panel you opened is a distribution panel aka "sub" panel then the neutral buss and "grounds" should be isolated from each other. It would be nice to see a ground buss and a neutral buss in the distribution (sub) panel but it is not often that you see them (at least in my area $$) . Depending on the brand of the panel you may have two "buss-es" present that can be physically disconnected from each other by a bar or some type of connection..

Ideally the ground connections (GEC) should /would be back at the origin of the electrical service entry. Check your local requirements..