Mixing neutral and grounding connection

[jxofaltrds]

Re: Mixing neutral and grounding connection

I do not know if this is a good thing or a bad thing.

I understand what Bennie is saying.

Sorry, Bennie I do not want to take away from your credibility.

Mike P.

 

[don_resqcapt19]

Re: Mixing neutral and grounding connection

Bennie,
How do your comments apply to 250.142(B)? This section very cleary prohibits the grounded conductor from being used to "bond" noncurrent carrying parts on the load side of the service disconnect. If a panel on the load side of the service disconnect uses the grounded conductor for equipment grounding purposes, then 250.142(B) has been violated. I don't care what this panel is called, but it if the conductors that feed it are not directly connected to the utilty, then it is on the load side of the service disconnect.
Don

 

[reynoldsk]

Re: Mixing neutral and grounding connection

If the neutral and the ground are not separated after the panel there will be current flow on the ground throughout the building. Which also means that there will be current flow through everything that is grounded between the load and the source.

The main problems I see with this is:

If for some reason we inadvertanly broke the ground path, a potential would appear across the break during normal operation.

 

[roger]

Re: Mixing neutral and grounding connection

Reynoldsk,

If for some reason we inadvertanly broke the ground path, a potential would appear across the break during normal operation.

yes it would, but that wouldn't be any different than any time a grounded conductor was opened under load.

With the circuit open would there be a problem or concern with equipment bonding to ground?

Roger

 

[bennie]

Re: Mixing neutral and grounding connection

Utility power is connected to the premises wiring at the distribution panels. The number of switches in the service entrance feeder make no difference.

All panels are service panels regardless of the location on the premises.

Service panels can be grounded by connecting to the neutral. Panel boards are not included in the list of premises wiring systems. Premises wiring equipment should not be grounded with the neutral only when there is a possibility of reverse polarity.

Case in point; What is the ground conductor to a water heater other than a non-current carrying neutral? The ground wire re grounds the neutral bus to a ground electrode, namely the water pipe. This is after the main switch.

What is the ground conductor to straight 240 equipment? This conductor is the same as the neutral being used for grounding. In other words, water heaters, air compressors, air conditioning compressors, 240 volt furnaces, are all grounded by the neutral.

This puts a new spin on using the neutral for grounding and calling panels sub-panels, and fabricating a different wiring procedure than a service panel.

 

[drg]

Re: Mixing neutral and grounding connection

Bennie, have heard you state before that nowhere in the NEC do they say subpanels, you seem so adamant with your views about this so I checked up and down the book could not find anything that says " subpanel" looked in the NEC 2002 and the handbook , in either one found nothing .......looked in the dictionary ,nothing .......in the illustrated guide to the NEC 2002 on page 175 a section shows REMOTE PANELBOARDS ( subpanels )it is refering to grounding and it is the only place I have seen the word subpanel.

In the book subpanels "is with parentheses "following remote panelboards.

Everyone calls them sub's and everyones knows what we are talking about when we say it but how come these books of reference don't use that term and what will you be willing to say that makes you so adamant about the subject ???

This really has got me extremely curious, and what you have said I will agree is true , would just like to know why it's this way.

John

 

[bennie]

Re: Mixing neutral and grounding connection

John: I learned what little I know, from the top scientists, engineers, and technicians in the electrical industry. I worked with people who wrote the upper level college text books.

Years ago, I wrote an article titled "Grounding Mythstakes of Electricity". I have the copyrights to the article.

The subject of grounding is confusing to many due to 95% of the text, in technical manuals, being nonsense.

Again, this is my own opinion.

 

[iwire]

Re: Mixing neutral and grounding connection

Originally posted by bennie:
All panels are service panels regardless of the location on the premises.

Bennie you are the one spinning things.

A 3 wire NM panel feeder will not pass a 2002 inspection.

I truly respect your knowledge Bennie, but you can not convince me that the NEC sees things the way you do on this issue.


Bob

 

[pierre]

Re: Mixing neutral and grounding connection

Bennie
You keep refering your comment back to NM cable. NM cable today has an equipment ground installed with the circuit conductors. Years ago, NM cable did not have an equipment ground and the older panels that were installed did not have an equipment ground either.

Today an equipment grounding conductor is required to be installed to a panel downstream of the first point of disconnect from the serving utility. These downstream panels are not service panels and it will only create more confusion for some by calling them service panels. The delineation for this is not the enclosure, but the disconnect.

In TODAYS installations, everywhere one looks there are metallic paths back to the service disconnect that are the 'effective ground fault current path' for the purpose of opening an overcurrent protective device (fuse, circuit breaker, etc..).
If we were to wire in the fashion you describe, with the REQUIREMENTS that are set forth for us, there would be multiple problems on that system, some of them creating a hazardous situation.
This wiring method we use today has been in place for such an amount of time, that it would become very, very difficult to change to an ungrounded system to rectify some of the problems that a grounded system inherently has.

Including my post, this subject has been beaten to death!!!
Of course this is my opinion

Pierre

Bob
When do you sleep?

[ March 03, 2004, 07:28 AM: Message edited by: pierre ]

 

[Ed MacLaren]

Re: Mixing neutral and grounding connection

Some months ago, I made the suggestion that there should be a forum, one that is not presented as an NEC forum, where controversial opinions, such as some of those put forward by Bennie, could be fully discussed.

I enjoy such discussions, but I'm concerned about causing confusion for those who come here expecting to get answers that conform to the NEC.

Ed

 

[bennie]

Re: Mixing neutral and grounding connection

I will drop this subject, but in my opinion my interpretation is exactly as spelled out,and intended, in the NEC.

I am sorry that some are uncomfortable with my statements. If everyone agreed on the meaning of the NEC sections, there would be no need in these forums.

Mike Holt probably does not like my posts but look at the website forums that get no action and have been shut down. Mike Holt's forum gets more hits than all the others combined. Start quoting only the code numbers and watch the action decrease.

I can disprove a lot of the commonly accepted procedures and beliefs. The SDS topic, the sub-panel topic, and the belief that water and gas pipe fittings can not have a straight thread, are just a few.

 

[drg]

Re: Mixing neutral and grounding connection

Bennie, you have made it clear more than once that your opinions are yours and not meant to mislead anyone.......

Understanding how to get along at work and using the NEC 2002 codes is paramount to other opinions.

Abstracted views sometimes help us understand things that seem simple but they are not, at least it makes a person read over and over again to find a good answer to why things work the way they do.

I do not plan on going to work and tell someone that there is no such thing as a subpanel,stuff like that would cause me all kinds of problems but at least with the help of your views and discussions that others have brought up, today I have a better working knowledge of the subject than yesterday .

Your opinions cause a person to think a little harder and search a lot deeper for a real answer other than just go to page 1 and see answer 2 and then not think about the subject anymore.


John, have a good day everyone.

 

[Ed MacLaren]

Re: Mixing neutral and grounding connection

If everyone agreed on the meaning of the NEC sections, there would be no need in these forums.

I agree. I find these controversial subjects the most interesting, and always check out Bennie's posts.

Because I do not know the actual wording of NEC rules, I am more interested in the basic electrical principles underlying the rule.

I wasn't suggesting a different forum, I meant a "category" in this forum where one would feel free to criticize the "establishment".

Ed

 

[karl riley]

Re: Mixing neutral and grounding connection

Ed, the only trouble with "discussing" these ideas with Bennie, is that his opinion never changes and never responds to the posts which point out his misunderstandings. I don't call this discussion, I call it a broken phonograph record. Sorry, Bennie, but I am tired of going over and over the same thing with no increase of understanding resulting.

And in regard to referencing engineers and writers of electrical textbooks, I have found a great deal of ignorance in relation to grounding in some of these books. I had a discussion with a Professor of Electrical Engineering from a Colorado university in which he adamantly stated that a constant DC current induces a constant current in parallel conductors. If one of my 7th grade science students had said that in a test paper (I used to teach science at several levels) he would have failed the test. And this guy was a Professor!

Karl

 

[Neelesh]

Re: Mixing neutral and grounding connection

I feel this is related to safety.
If grounding is derived from Neutral at main entrance level of installation then it shall not be mixed again therafter.
Earth leakage devices like RCD/ELCB may mulfunction in such cases