Need to know if my grounds and neutrals are connected right

HouseHelper · 01-06-2012, 03:01 PM

Listen to the guys here about where and how to bond the neutral and ground. The local guys are either wrong or you are misunderstanding their responses.

This is from a licensed master electrician (since 1996).

sissond · 01-06-2012, 03:15 PM

Dorlow, I'm new here but I have done extensive research for the past 2 months on running a feeder to a detached structure. Everything that the guys here have told you is in line with what I have read on reputable websites, in books, heard from electricians I've met, and have confirmed with the local inspector.

Either the guys you are talking to locally are either, 1. all incompetent, 2. messing with you, 3. confusing you to the point where you don't understand what they are telling you.

Just listen to these guys on this site and fix your issues! Stop continuously looking for a second opinion.

I had one of my uncle's electricians do our service upgrade which included installing a new main panel and turning the old panel into a sub-panel. The local inspector told me that our electrician did the best work he has ever had the pleasure of inspecting. And this inspector hates everyone and everything.

I can tell you that right now our main panel has the neutral and ground bus bars connected/bonded and in our sub-panel they are disconnected. That is how the inspector (and everyone else I've spoke to) says I should set up the sub-panel in our detached garage as well.

Either the guy you spoke with, or you, have it backwards.

By the way, from the posts I've read in this thread, you had no where near the knowledge necessary to tackle such an undertaking. My knowledge about running a feeder was similar to yours, so instead of jumping into it head first, I took my time and learned. Now when I finally have time to run my electrical, I'm confident that it may actually pass the inspection. And at the very least, no one will die and the garage won't burn down.

I have spent most of my free time in the last few years since I moved here fixing up my old house from numerous mistakes/hazards made by hack contractors and ignorant DIYer's. Do homeowners like me a favor and stop attempting tasks before you know what you're doing.

Stubbie · 01-06-2012, 03:34 PM

Dorlow

I have to believe there is a miscommunication between you and the local electricians (excluding the school maintenance guy). Any electrician that has been doing this for a while knows that you only bond neutral and ground at the service equipment. In your case that is the enclosure where your single Murray main breaker is located. All the panels after that are fed with four wires (H-H-N-Grd) and have their neutrals and grounds separated in the panels.

Part of the problem is your experience with electrical and the correct understanding of the differences between neutral and equipment grounding vs earth grounding .ie.. ground rods etc.

If you like I will take the time to post several diagrams showing you the why of this neutral ground bonding thing. You have some misconceptions that need to be cleared up.

If so post back and through the course of this afternoon we will discuss the diagrams which you are free to copy and show your electricians for verification of accuracy.

I may take a few hours break but the other electricians and knowledgable members here can discuss my diagrams just as well as I can. These members are very knowledgable ... many are master electricians and residential wireman qualified. As for me I never feel comfortable on this forum spouting about my credentials as many here on this forum are more qualified than I .. especially in residential. Nonetheless I have been in the trade for many years and am now retired.

So if your game I'll take the time

stubbie

jproffer · 01-06-2012, 03:37 PM

Quote:

Originally Posted by dorlow

So, I talked to the head maintenance guy yesterday at a school I work at. He's a licensed electrician and does all of the school's electrical work. They pass their inspections, so I think he knows what he's talking about. I showed him the pictures in this forum. He told me the only place where the grounds and neutrals need to be separated by code is in the main panel. He told me to put another bar in the main panel that would be grounded to the box and move all my grounds to that and then move the ground wire to that bar. The neutrals should be isolated and not connected to anything.

He said after that, that the grounds and neutrals can be all on the same bars. I then ran my idea about changing my barn from being 240 to 120 so i'd only have one hot. one 2 gauge would be hot, one 2 gauge would be neutral and the 4 gauge would be ground. He said that would be fine as long as I tape the ground with green tape and the neutral with white... then it's code.

The only thing he pointed out that breaks code in my main box is that the wires running from the main box to the first sub panel, the wires aren't in conduit... and code states it needs to be in that. Which that will be an easy and cheap fix.

But the one thing I haven't gotten an answer from him on yet is, if grounds and neutrals are ok to be one and the same after the main box, then why bother running a ground and neutral from the barn to the house? Both wires will be running from the same bar in the barn to the same barn in the house... so they're just a duplicate wire. The only thing this confirms is I need to bond the neutral and grounds in the barn.

GOOD GRACIOUS!!!!!

I'm done

dorlow · 01-06-2012, 04:11 PM

Quote:

Originally Posted by Stubbie

Hmmmmm I wonder why he couldn't answer that ???

He couldn't answer that because I never asked him. I thought the question after I left.

Missouri Bound · 01-06-2012, 04:17 PM

If you ask enough people, someone will agree with you. It worked for Charles Manson, Jim Jones, and lest we forget Adolf Hitler.

Stubbie · 01-06-2012, 04:20 PM

Quote:

Originally Posted by dorlow

He couldn't answer that because I never asked him. I thought the question after I left.

Well that certainly shows you are wondering what doesn't make sense.

Look .. why don't we clean the slate and start over ... did you read my other post ?

Billy_Bob · 01-06-2012, 04:42 PM

Quote:

Originally Posted by dorlow

...I have 3 electricians I know personally and they all contradict what everyone is stating in this forum thread...

For most things in life, you can ask 5 people advice and what the majority say is usually pretty good advice. And I do advise people to do that, especially with people/relationship problems...

BUT! I moved to a small town awhile back and encountered the same situation you are in. So far as technical things go, most people here are wrong and misinformed.

Many people here have never lived out of the area. All they know is what people here do. And the same misinformation goes 'round and 'round for years.

All I can say is if you need medical advice, go to a doctor.

If you want to learn to drive and learn the driving rules, read the Department of Motor Vehicles booklet.

If you want to properly repair a car, get a "Factory Service Manual" set of books - 4 books to set. And about 2000 pages total on the specific repair of one vehicle of one model year. Here is an example...
http://www.ncttora.com/fsm/1993/index.html

If you want to properly repair an appliance, you use the troubleshooting guides in a Factory Service Manual for that appliance. Here is an example...
http://bryantrv.com/docs.html

If you have a legal problem and go before a judge, the ruling would be based on LAW, not on what other people say or do.

And for the proper way to do electrical work, the correct information can be found at your local electrical inspector's office and the National Electrical Code books...
http://www.nfpa.org/catalog/product....order_src=B119

Here is one with pictures...
http://www.nfpa.org/catalog/product....order_src=B119

There is a saying: "Get it straight from the horse's mouth!"

That means...
"From an authoritative or dependable source."

dorlow · 01-06-2012, 05:08 PM

what about this?

Multiple Building Power/Grounding
NEC 250.32 [2002 - 2005] Common ac service
If no common grounding conductor extends between the buildings with multiple circuits then each
building must have an established grounding electrode system with a separate neutral-to-ground
bond in each building.
If a common grounded and grounding conductor extends between the buildings, and multiple circuits
exist then a grounding terminal will be required in the connected buildings and no individual neutral-
to-ground bonds will be permitted in each additional building.
If a single circuit extends to a second building and both grounded and grounding conductors extend
to the second building then no ground terminal will be required and a neutral-to-ground bond cannot
be established at the second building.

According to that, if I didn't send a ground to the barn, then I just need to run a ground rod and the neutral and ground need to be connected. Or would I be going by the 3rd statement?

<*(((>< · 01-06-2012, 05:44 PM

Quote:

Originally Posted by dorlow

what about this?

Multiple Building Power/Grounding
NEC 250.32 [2002 - 2005] Common ac service
If no common grounding conductor extends between the buildings with multiple circuits then each
building must have an established grounding electrode system with a separate neutral-to-ground
bond in each building.
If a common grounded and grounding conductor extends between the buildings, and multiple circuits
exist then a grounding terminal will be required in the connected buildings and no individual neutral-
to-ground bonds will be permitted in each additional building.
If a single circuit extends to a second building and both grounded and grounding conductors extend
to the second building then no ground terminal will be required and a neutral-to-ground bond cannot
be established at the second building.

According to that, if I didn't send a ground to the barn, then I just need to run a ground rod and the neutral and ground need to be connected. Or would I be going by the 3rd statement?

You're on the right track but how about checking the 2008 NEC codes as that is when it changed. I'm sure you will find the answer to your question and that it is what people here have been saying.

You do know that ground rods aren't there to dissipate regularly current but rather a lightning strike event, this is a common misconception. The reason that the neutral and ground are tied together in the main service panel is so that the electricity has a channel to head back to the transformer to even out.

Why don't you look at the post below, as Stubbie has done a great job with his post:
Sub panel grounding

brric · 01-06-2012, 05:46 PM

Every one of your panels past the main service disconnect(the big black breaker with the large wires) requires isolated neutrals and grounding conductors--period.

Stubbie · 01-06-2012, 06:46 PM

I'll try to explain. In your case you only have a 3 wire feeder to your barn. This is permissible under certain exceptions and is dependent on the NEC code cycle in force in your local jurisdiction. If your on 2005 or before and no local amendments to the contrary you may run a 3 wire feeder from the service equipment to a detached building. This is only if you do not have any other metallic paths between the building with the service equipment and the building your feeder supplies. This means you cannot now or in the future run metal water pipes or phone or data cables or any other wiring or metal paths that use the grounding system of the dwelling and detached building.

This per 2011 NEC which allows you to have a 3 wire feeder that is existing.

In your case it was not existing

Now this is dependent on the code cycle your jurisdiction is enforcing as said earlier. Pay attention to the highlighted exception.

NEC 2011

250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.
Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non–current-carrying metal
parts of equipment.
(B) Grounded Systems. For a grounded system at the
separate building or structure, an equipment grounding conductor
as described in 250.118 shall be run with the supply
conductors and be connected to the building or structure
disconnecting means and to the grounding electrode(s). The
equipment grounding conductor shall be used for grounding
or bonding of equipment, structures, or frames required
to be grounded or bonded. The equipment grounding
conductor shall be sized in accordance with 250.122.
Any installed grounded conductor shall not be connected
to the equipment grounding conductor or to the grounding
electrode(s).

Quote:

Exception: For existing premises wiring systems only, the
grounded conductor run with the supply to the building or
structure shall be permitted to be connected to the building
or structure disconnecting means and to the grounding
electrode(s) and shall be used for grounding or bonding of
equipment, structures, or frames required to be grounded
or bonded where all the requirements of (1), (2), and (3)
are met:
(1) An equipment grounding conductor is not run with the
supply to the building or structure.
(2) There are no continuous metallic paths bonded to the
grounding system in each building or structure involved.
(3) Ground-fault protection of equipment has not been installed
on the supply side of the feeder(s).
Where the grounded conductor is used for grounding in
accordance with the provision of this exception, the size of
the grounded conductor shall not be smaller than the larger
of either of the following:
(1) That required by 220.61
(2) That required by 250.122

Now forget the grounding electrode requirement .. you keep thinking this has something to do with equipment grounding .. this is not why you bond neutral and equipment grounding.

So if you are on 2005 or earlier you may, considering any local amendments to the NEC, run a 3 wire feeder from the Service Equipment to the panel in the garage in accordance with the exception.

In your case you are not running your feeder from the service equipment but from a panel downstream of the service equipment which is required by code to be fed with four wires or three current carrying wires and metal conduit for the equipment ground..

Put a flow chart together ... your first panel after the service disconnect is fed by four wires which is correct but the ground and neutral were not separated, major code violation, and you now have neutral current returning to the main disconnect panel over the bare equipment ground wire and the feeder neutral. You never want normal system current on the equipment ground where it is not expected. This bonding is energizing all bonded metal, your equipment ground wires and feeder egc as you have given the neutral current other paths to use to get back to the service equipment and then to the source (transformer).

Your second panel is next to the other sub-panel it is fed by 3 wires (another code violation) and you bonded neutral and ground but you do not have your (case) main bonding means installed in the neutral bar. Any hot phase fault to ground or that metal will not trip a circuit breaker ... the metal will be just like a live bare wire and will shock or electrocute you if you touch it and a fault is present.

You ran a three wire feeder from the second panel to your barn (another code violation). In that panel you connected to the left bar with the feeder neutral and one branch circuit neutral ... on the right you connected your grounding electrode conductor and the branch circuit ground and installed the bonding jumper to the metal case.

The neutral is isolated from ground and the case in that panel which is incorrectly fed with a 3 wire feeder. This is telling me you think that the path to earth over the grounding electrode conductor is what is required to open (trip) your circuit breaker. As it is wired right now you will not be able to trip any circuit breaker on a ground fault.

So think about this ..without a complete low impedance/resistance circuit back to the transformer (source) for fault current over an 'effective ground fault path' your circuit breakers will never trip and thereby protect you from electrocution. Notice I said back to the transformer not earth .

As it stands you have no protection against ground fault and electrocution at the second sub-panel or the barn sub-panel.

dorlow · 01-06-2012, 07:50 PM

A question I have is, according to the articles here, it's OK to send a 3 wire feed to the barn under 2005 rules. In 2008 rules, it's not ok anymore. I know this statement doesn't change the safety of the situation... but electricity has been around for a long time. They didn't figure out that breakers wouldn't trip unless a ground wire was ran until after 2008? It's hard to believe that there has to be millions or billions of electrians from the time Benjamin Franklin discovered it in 1750 until now... So from 1750 to 2005 (205 years), all electricians thought it was safe and breakers or fuses would break with only a 3 wire feed, and only 7 years ago they figured out they where wrong for the past 199 years? It's just hard for me to believe that millions or billions of electricians didn't get electrocuted enough if it's unsafe and figured it out a long time before 7 years ago.

Quote:

Originally Posted by Stubbie

I'll try to explain. In your case you only have a 3 wire feeder to your barn. This is permissible under certain exceptions and is dependent on the NEC code cycle in force in your local jurisdiction. If your on 2005 or before and no local amendments to the contrary you may run a 3 wire feeder from the service equipment to a detached building. This is only if you do not have any other metallic paths between the building with the service equipment and the building your feeder supplies. This means you cannot now or in the future run metal water pipes or phone or data cables or any other wiring or metal paths that use the grounding system of the dwelling and detached building.

This per 2011 NEC which allows you to have a 3 wire feeder that is existing.

In your case it was not existing

Now this is dependent on the code cycle your jurisdiction is enforcing as said earlier. Pay attention to the highlighted exception.

NEC 2011

250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.
Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non–current-carrying metal
parts of equipment.
(B) Grounded Systems. For a grounded system at the
separate building or structure, an equipment grounding conductor
as described in 250.118 shall be run with the supply
conductors and be connected to the building or structure
disconnecting means and to the grounding electrode(s). The
equipment grounding conductor shall be used for grounding
or bonding of equipment, structures, or frames required
to be grounded or bonded. The equipment grounding
conductor shall be sized in accordance with 250.122.
Any installed grounded conductor shall not be connected
to the equipment grounding conductor or to the grounding
electrode(s).
Now forget the grounding electrode requirement .. you keep thinking this has something to do with equipment grounding .. this is not why you bond neutral and equipment grounding.

So if you are on 2005 or earlier you may, considering any local amendments to the NEC, run a 3 wire feeder from the Service Equipment to the panel in the garage in accordance with the exception.

In your case you are not running your feeder from the service equipment but from a panel downstream of the service equipment which is required by code to be fed with four wires or three current carrying wires and metal conduit for the equipment ground..

Put a flow chart together ... your first panel after the service disconnect is fed by four wires which is correct but the ground and neutral were not separated, major code violation, and you now have neutral current returning to the main disconnect panel over the bare equipment ground wire and the feeder neutral. You never want normal system current on the equipment ground where it is not expected. This bonding is energizing all bonded metal, your equipment ground wires and feeder egc as you have given the neutral current other paths to use to get back to the service equipment and then to the source (transformer).

Your second panel is next to the other sub-panel it is fed by 3 wires (another code violation) and you bonded neutral and ground but you do not have your (case) main bonding means installed in the neutral bar. Any hot phase fault to ground or that metal will not trip a circuit breaker ... the metal will be just like a live bare wire and will shock or electrocute you if you touch it and a fault is present.

You ran a three wire feeder from the second panel to your barn (another code violation). In that panel you connected to the left bar with the feeder neutral and one branch circuit neutral ... on the right you connected your grounding electrode conductor and the branch circuit ground and installed the bonding jumper to the metal case.

The neutral is isolated from ground and the case in that panel which is incorrectly fed with a 3 wire feeder. This is telling me you think that the path to earth over the grounding electrode conductor is what is required to open (trip) your circuit breaker. As it is wired right now you will not be able to trip any circuit breaker on a ground fault.

So think about this ..without a complete low impedance/resistance circuit back to the transformer (source) for fault current over an 'effective ground fault path' your circuit breakers will never trip and thereby protect you from electrocution. Notice I said back to the transformer not earth .

As it stands you have no protection against ground fault and electrocution at the second sub-panel or the barn sub-panel.

Stubbie · 01-06-2012, 08:45 PM

You still don't understand what is going on. I'm not sure you are going to be convinced of your errors. The people who inspected your home were not electricians but home inspectors, evidently ones that did not have a very good electrical knowledge.

One way to convince you that you do not understand may be to get you to explain how a breaker is going to trip at your barn panel the way it is presently wired. If you can do that I'll go away and you can leave it as is or however your locals are telling you is ok.

Billy_Bob · 01-06-2012, 08:53 PM

Quote:

Originally Posted by dorlow

A question I have is, according to the articles here, it's OK to send a 3 wire feed to the barn under 2005 rules. In 2008 rules, it's not ok anymore. I know this statement doesn't change the safety of the situation... but electricity has been around for a long time. They didn't figure out that breakers wouldn't trip unless a ground wire was ran until after 2008?...

That is a good question.

There also used to be 2 lane highways, then they replaced many of them with divided highways. Cars did not have air bags.

And in the 60's, homes had 2 prong outlets, no GFCI outlets, and no smoke detectors. Many people lived in those homes and never had any problems...

...however MANY other people were electrocuted or died in electrical fires.

We learn from these accidents. Then take steps to make things safer.

So IF everything electrical would ALWAYS function properly. And EVERYTHING powered by electricity always functioned properly. And all electrical circuits were ALWAYS 100% intact and connected. Then many electrical code rules would not be needed.

But we live in the real world and things happen to dangerously damage electrical circuits and electrical devices.

As it turns out, there are some *very* smart people out there who have been able to design things so we are still safe even when an electrical malfunction happens.

Ground wires get cut.
Neutral wires come loose.
Someone digs a trench and cuts an electrical line.
Someone drills a hole in a wall and cuts an electrical wire.

These things happen everyday! But when they do happen, an up to code electrical system will assure you that you and your family are still safe!

Not the case with older electrical systems.

Basically it is the case of there being a problem. Then doing something about it to reduce or eliminate those problems in the future.

As to why this is being addressed now and not a long time ago... Well once upon a time there was just one main electrical panel in a home. One outlet per room. No need for any subpanels.

Now everybody and their brother has a subpanel to power all those electrical gadgets.

Safety problems with subpanels have been noted and corrected.

Something new to come along will be electric vehicles. I imagine there will be problems with that too. If there are, then changes to the code will be made to make it safer. If no problems, then no need for any changes.

Simple as that!