To ground or not to ground...

So glad you met up with the right man. The lack of the 4th or ground conductor from the Service was the Main Idea & difficulty surrounding your Post. I am pleased he approve our remedy.

Now; send me a 2way ticket & I'll help you install it };-) I can dream & joke a bit at the same time.

Roy

From: the snipped-for-privacy@sbcglobal.net (tarin) I just visited with our local inspector who been doin' this stuff for nigh on 40 years. He said that code NOW requires 4 wires. However, since I've known him for years, he gave me some advise "off the record". He concurred with what ROY has said: i.e., Bond the ground and neutral at the service entrance and isolate them at the subpanel. I now understand the reason for the 4th wire, but the chances are astronomical that the neutral will fail and if it should with an isolated ground, then everything will just go dead. Better that than being electrocuted by a suddenly hot ground. Thanks guys!!! in article 423f1240$0$ snipped-for-privacy@dingus.crosslink.net, John Gilmer at snipped-for-privacy@crosslink.net wrote on 3/21/05 12:33 PM: You only have three conductors between the yard pole and the cabin. "Around here" a building site ran power from a "service" drop at a pole. That's where the meter and a BIG disconnect (can't tell from looking.) They DEFINITELY ran FOUR wires to the construction area (you could COUNT them.) So "by the book" (at least in Central VA - Dominion Power) you run the four wires. That said, I still find myself wondering what would be a better way (all things consideered.) Personally, I like the idea of bonding the neutral where the "electric" enters the building. =A0 AND if you do that, it's downright silly to run four wires.

ROY---->

I'm using a "Square D" load center. According to my friend, the NEUTRAL is not bonded to the box. To bond it to the metal casing, I would have to utilize the green grounding screw provided with the setup.

Since I don't want to do that, I simply leave that step out and buy a separate EQUIPMENT GROUNDING BAR and attach that to the inside of the box, thus grounding the enclosure, but not the NEUTRAL.

THIS = ISOLATED NEUTRAL/GROUND.

I then attach my bare grounds to the EQUIPMENT GROUNDING BAR and my white neutrals to the pre-existing neutral buss on the panel.

Does this sound about right? Obviously, this is not to code, but I feel it is relatively safe. Don't you agree?

In addition, since my satellite connection is on the opposite side of the house from the panel, I thought I might drive the second grounding rod there and bind the two rods beneath the house a run of about 24 ft.

IF I bury this bare bonding cable about 2 ft deep, wouldn't that provide a better ground?

P.S. Where are you? I want to know before I commit to a ticket. ;-)

in article snipped-for-privacy@storefull-3251.bay.webtv.net, Roy Q.T. at snipped-for-privacy@webtv.net wrote on 3/21/05 5:04 PM:

Mr. Tarin I guess I'm not that good a joker:-) Bronx NY USA, at your service.

I like G.E for City use but Square D is right true for your Country Cabin setting.

Regarding the seperate Grounding Buss Bar and Wire attachment that is just about right & how I'd do it., the measure is up-to-code (actually read it somewhere in my NEC guidebook) we are in agreement.

The grounding conductor burried under the cabin sounds just about right as long you don't let anyone in the future go diggin for gold down there ruining the continuity of it. I'll check if other than purely electrode contact will hinder or reduce it's efficacy. I don't think we need or should bind the 2 seperate electrodes since it's more than 6ft from the

1st electode i am almost sure they should not coverge until the Buss Bar perhaps shy the width of the panel and up in two lengths of conduit to protect them from the Elements (PVC) up with scary Use/ID Tags or Proper Markings just in case someone gets by you and decides to mine anyway :-) ~ (I am guessing the Panel is already Installed somewhere near the Center of the Cabin?)

We could design a pattern prior to locating the electrodes so as to make a geometric array (even if partially under the soil) with respect to the layout of the Electrode/Conductors/Subpanel & Satelite Location. I don't think we should bond the Tel Co Box to your Electrical sys. {harmonics}.

I've never been out there. Attentively }:-{) Roy

From: the snipped-for-privacy@sbcglobal.net (tarin) ROY----> I'm using a "Square D" load center. According to my friend, the NEUTRAL is not bonded to the box. To bond it to the metal casing, I would have to utilize the green grounding screw provided with the setup. Since I don't want to do that, I simply leave that step out and buy a separate EQUIPMENT GROUNDING BAR and attach that to the inside of the box, thus grounding the enclosure, but not the NEUTRAL. THIS =3D ISOLATED NEUTRAL/GROUND. I then attach my bare grounds to the EQUIPMENT GROUNDING BAR and my white neutrals to the pre-existing neutral buss on the panel. Does this sound about right? Obviously, this is not to code, but I feel it is relatively safe. Don't you agree? In addition, since my satellite connection is on the opposite side of the house from the panel, I thought I might drive the second grounding rod there and bind the two rods beneath the house a run of about 24 ft. IF I bury this bare bonding cable about 2 ft deep, wouldn't that provide a better ground? P.S. Where are you? I want to know before I commit to a ticket. ;-) in article snipped-for-privacy@storefull-3251.bay.webtv.net, Roy Q.T. at snipped-for-privacy@webtv.net wrote on 3/21/05 5:04 PM: So glad you met up with the right man. The lack of the 4th or ground conductor from the Service was the Main Idea & difficulty surrounding your Post. I am pleased he approve our remedy. Now; send me a 2way ticket & I'll help you install it };-) I can dream & joke a bit at the same time. Roy

From: the snipped-for-privacy@sbcglobal.net (tarin) I just visited with our local inspector who been doin' this stuff for nigh on 40 years. He said that code NOW requires 4 wires. However, since I've known him for years, he gave me some advise "off the record". He concurred with what ROY has said: i.e., Bond the ground and neutral at the service entrance and isolate them at the subpanel. I now understand the reason for the 4th wire, but the chances are astronomical that the neutral will fail and if it should with an isolated ground, then everything will just go dead. Better that than being electrocuted by a suddenly hot ground. Thanks guys!!!

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D Thanks just the same John

So "by the book" (at least in Central VA - Dominion Power) you run the four wires. That said, I still find myself wondering what would be a better way (all things considered.) Personally, I like the idea of bonding the neutral where the "electric" enters the building. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= John A Rural Configuration is More Likely to not be "by the book" with Coded Amendments. =AE~>

Don't feel obligated any further than this.Please, I found it helpful too & enjoyed thus far.I think I've found my new nitch on the web};-) Roy Q.T.~ E.E.Tech

tarin wrote:

Tarin Please reconsider! I have been an electrician and a fire fighter for over thirty years. I have seen a few electrical injuries and even a couple of electrocution victims. There never pretty. I may not have been in the industry for as long as that inspector but in this case he is wrong. If you do what the inspector has said you will be in real danger. With a three wire feeder if you don't bond the neutral to the building disconnecting means enclosure you will not have an effective fault clearing path back to the source of supply. Both grounding (earthing) and bonding are essential to having a safe system. Your equipment grounding buss and neutral buss will only be connected to each other by the earth. You will have built the system in direct violation of the US NEC which is the code that is enforced as law state wide in Virginia. The applicable code sections read:

250.4 General Requirements for Grounding and Bonding. The following general requirements identify what grounding and bonding of electrical systems are required to accomplish. The prescriptive methods contained in Article 250 shall be followed to comply with the performance requirements of this section. (A) Grounded Systems. (1) Electrical System Grounding. Electrical systems that are grounded shall be connected to earth in a manner that will limit the voltage imposed by lightning, line surges, or unintentional contact with higher-voltage lines and that will stabilize the voltage to earth during normal operation. (2) Grounding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials. (3) Bonding of Electrical Equipment. Non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. (4) Bonding of Electrically Conductive Materials and Other Equipment. Electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path. (5) Effective Ground-Fault Current Path. Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a permanent, low-impedance circuit capable of safely carrying the maximum ground-fault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be used as the sole equipment grounding conductor or effective ground-fault current path.

Take special note of the (3) and (5) above. If you isolate the neutral from the panel cabinet at the house the only fault clearing path between the house's Equipment grounding system and the transformer that supplies the house with it's power will be the grounding electrode system at the house the earth itself and the grounding electrode at the transformer. The resistance of that fault pathway will be too high to carry enough current to clear a fault and all the metallic parts of the electrical system will become energized at 120 volts relative to the earth under a ground fault condition. Ground faults are much more common occurrences than open neutrals are. Even though the earth will not carry enough current to cause the breaker or fuse to open it will carry the tenth of an amp that it takes to kill you or a member of your family. A ground fault under such conditions will be present until it is repaired. You won't even know that you have a fault until someone gets shocked.

-- Yours in Service Master Fire Fighter Thomas D. Horne, Speaking for himself and not the Takoma Park Volunteer Fire Department a cooperating agency of the Montgomery County Fire and Rescue Service, Maryland,

In answer to your last question burying that bonding cable two feet deep would improve the grounding at your house. Better still would be to run a bare number two copper conductor clean around the house buried at least two & one half feet deep. That conductor is called a ground ring and is a grounding electrode in it's own right. If you install a ground ring you are not required to install driven rods.

250.50 Grounding Electrode System. If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system. Where none of these electrodes are available, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used. 250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding. (4) Ground Ring. A ground ring encircling the building or structure, in direct contact with the earth, consisting of at least 6.0 m (20 ft) of bare copper conductor not smaller than 2 AWG. 250.53 Grounding Electrode System Installation. (F) Ground Ring. The ground ring shall be buried at a depth below the earth?s surface of not less than 750 mm (30 in.).

The best practice with any grounding electrode is to install it below the permanent moisture level i.e. below the dry season water table. Doing so is often impractical.

If you leave the equipment grounding system isolated from the neutral and a subsequent ground fault develops then even changing a light bulb will be deadly dangerous. With one hand on the grounded body of the fixture and the other hand screwing in the bulb any contact with the screw shell of an Edison based light bulb, which is connected to the neutral conductor through the screw shell of the bulb socket of the fixture, will result in a shock from hand to hand through your chest cavity. It only takes a tenth of an Ampere to kill.

By the way guys it is considered bad manners to post your reply above what you are replying to because it makes it harder for other folks to follow the conversation. Just hold control and tap the end key before starting your reply. That will move the cursor to the very bottom of the quited text. That is the opposite of Email etiquette were it is presumed the recipient is already aware of the previous exchanges since they were a party to them.

-- Tom H

The code requires that all wire carried utilities into your home, including the telephone network protector, be grounded to the same grounding electrode system. If separate electrodes are installed they must be bonded together to form one single grounding electrode system. Failing to do so will cause any spike or surge on one utility to equalize to the other utility through the devices that use both utilities. In the case of your telephone line any failure to bond it's network protector to the electrical system ground will result in surge or spike damage to answering and fax machines, telephone modems, or any other device that is connected to both the phone line and electric power.

-- Tom H

Roy I mean you no harm but I have to tell you and anybody else that is reading this exchange that you are giving out dangerous advice. All of the approaches you have suggested thus far can lead to equipment damage, fires of electrical origin, serious injury, and even death. You really need to find another niche before someone takes your bad advice and ends up dead.

-- Tom H

Mr. Horne,

Thank you for your very thoughtful and thourough explanati>If you isolate the neutral from the panel cabinet at the house the only fault

In my system, the NEUTRAL is bonded to ground in a 200 AMP service entry on a pole. This box has feed-through lugs.

From there I have a three wire feed to a grounded subpanel(on the house) that I intended to isolate from the NEUTRAL.

By binding the NEUTRAL to the GROUND at the subpanel I would in essence be bonding the two GROUNDS together through the NEUTRAL.

Would this not create a problem? Because there is not a 4th grounding wire run with the two conductors, wouldn't there be a difference in ground potentials?

Mr. Tom H

I already Stated the code that Prohibits Grounding the Neutral at a Subpanel of a System that is already Neutral/Grounded at the Service Disconnect,

Yet you insist in Harassing Mr. Tarin & Other here into believing your way is the Only correct way.

FURTHERMORE: You are even Challenging the Code Inspectors Decision (Not Good Form Fellow) as if your concern for Life is some how Greater than His that is His Job in his specific Field to Prevent the Lose of Life and Oversee Electrical Ethics. Other than charge you as a Nuisance:

With All Due Respect To Many Cases of Death By Electrocution you've seen in your Career., I, in my 28 years in the Field Have Not Caused Ever a single Shock Much Less the displeasure of Witnessing a Death so Horrific, as it apparently is Custom with your Fellow WorkClass Men., Nor Have any of The Men from my Training Academia Ever Suffered a Single Death due to Improper Handling or Design of an Electrical System.

If your Workmanship is anything close to the poor writing skills I've noted in you here today and that you've so Egregiously Displayed here., You should only Be Concerned about Yourself and Seek Professional Help & Counselling.

Your Replies are Alarming and Unfounded., only of your Lack, of Ethics Towards Others & Security in your Profession.

Sincerely: Roy Q.T

Randell: I wish I had the funds to go pick-up Mr Tom H. and go to your Stretch and let him handle the task as he implies but it is not in our Fate to go see him connect a system only to watch it explode.

I will not joke or Humor the night, about the adverse universe he seems to be writing from, his writings read so tragic, but I think it's best he measure his word and watch his troubleshooting, if he cannot follow form and advice.

Roy

From: the snipped-for-privacy@sbcglobal.net (tarin) Mr. Horne, Thank you for your very thoughtful and thourough explanation of the problem. I do have a few questions though, if you don't mind. You said: If you isolate the neutral from the panel cabinet at the house the only fault clearing path between the house's Equipment grounding system and the transformer that supplies the house with it's power will be the grounding electrode system at the house the earth itself and the grounding electrode at the transformer. In my system, the NEUTRAL is bonded to ground in a 200 AMP service entry on a pole. This box has feed-through lugs. From there I have a three wire feed to a grounded subpanel(on the house) that I intended to isolate from the NEUTRAL. By binding the NEUTRAL to the GROUND at the subpanel I would in essence be bonding the two GROUNDS together through the NEUTRAL. Would this not create a problem? Because there is not a 4th grounding wire run with the two conductors, wouldn't there be a difference in ground potentials?

Yeah, yeah.

BUT, in a "typical" suburban application, the pad mounted transformer has both primary and secondary neutrals bonded together. There is so much metal exposed to the soil that it doesn't really matter whether there is a ground rod at the pad.

When that three wire service enters the individual homes, it is again bonded to "local" ground.

Meanwhile, the telephone and cable "grounds" are bonded to the "local grounds" at each home (i.e.: the local ground used for bonding the neutral from the power company.

The reality is that the utilities create a giant "ground plane" of all their stuff.

But getting back to the original problem: the "code" would have us believe that there is some MAGIC about the electric meter. That a few feet beyond the meter the neutral and "ground" must no longer cross. There is nothing special about the meter: it doesn't interrupt the neutral. Thus, there should be no difference in bonding requirements between the meter being mounted on the wall of the house and the meter being mounted on a board set up next to a power pole.

But according to "the code" these situations are quite different.

Well, that's just BS.

No. You have no utilization equipment at the meter location.

The potential difference of concern is AT THE CABIN. That is where you will use your lights/appliances/whatever. You want the neutral

*at the cabin* to be as close to the potential of the physical ground *at the cabin* as possible.

A difference in ground potential from the meter location to the cabin location poses no hazard - they are too far apart for you to be exposed to the difference. But a difference at the cabin between the neutral at the cabin and the ground at the cabin is something you can be exposed to. There is no utilization equipment at the meter location to be adversely affected by ground loops.

You would be well served to read, understand and follow Mr. Horne's advice.

Ed

From: snipped-for-privacy@crosslink.net (John=A0Gilmer) The code requires that all wire carried utilities into your home, including the telephone network protector, be grounded to the same grounding electrode system. Yeah, yeah. BUT, in a "typical" suburban application, the pad mounted transformer has both primary and secondary neutrals bonded together. =A0 There is so much metal exposed to the soil that it doesn't really matter whether there is a ground rod at the pad. When that three wire service enters the individual homes, it is again bonded to "local" ground. Meanwhile, the telephone and cable "grounds" are bonded to the "local grounds" at each home (i.e.: the local ground used for bonding the neutral from the power company. If separate electrodes are installed they must be bonded together to form one single grounding electrode system. Failing to do so will cause any spike or surge on one utility to equalize to the other utility through the devices that use both utilities. In the case of your telephone line any failure to bond it's network protector to the electrical system ground will result in surge or spike damage to answering and fax machines, telephone modems, or any other device that is connected to both the phone line and electric power. The reality is that the utilities create a giant "ground plane" of all their stuff. But getting back to the original problem: the "code" would have us believe that there is some MAGIC about the electric meter. =A0 That a few feet beyond the meter the neutral and "ground" must no longer cross. =A0 There is nothing special about the meter: it doesn't interrupt the neutral. =A0 Thus, there should be no difference in bonding requirements between the meter being mounted on the wall of the house and the meter being mounted on a board set up next to a power pole. But according to "the code" these situations are quite different. Well, that's just BS.

I for the most part I concurred ror the codes sake, but, if i could use an elementary way to gather the why's & how's revolving the issues concerning The Neutral/Earth Bonding Measure Vs The Where-To's it is as Magic it doesn't explode right there at the Meter/Disconnect regardless where it may be.

How so? Elementary< Sample: An Energetic Movement Seen by the Human Eye ie Magnetism< if you have Two Powerful Magnets next to each other the will attract and Bond Electrically/ Electronically though Not Chemically.

Separated by a Healthy Distance their Energy is Unapparent. In the case of Distant Charged Electrical Panel Bodies, Distance =3D Null Energy as well, Add a Path for The Energy & All The Energetic Manifestation Changes.

I gather they take their chances at the Meter/Disconnect for a reason Null Energy to Earth but Conductive to the Grid System.

In 30 years of Service: I'VE NEVER SEEN A NEUTRAL (current carrying return or single common conductor ) GROUNDED TO EARTH NOR BONDED TO EQUIPMENT AT ANY MAN OPERATED HOUSEHOLD DISTRIBUTION PANEL

[As in Hot Conductors; it's called a short circuit]

Thank [all concerned] You Very Much.

" no utilization" ? There Is a motorized contraption (energetic constant) at the meter location....

you that call yourselves engineers,You best be sure of what your saying here with regards to this Specific Manner Installation. where Bonding Is required By Law., Neutral Jumping, Not.

I withdraw From: snipped-for-privacy@bellatlantic.net tarin wrote: Mr. Horne, Thank you for your very thoughtful and thourough explanation of the problem. I do have a few questions though, if you don't mind. You said: If you isolate the neutral from the panel cabinet at the house the only fault clearing path between the house's Equipment grounding system and the transformer that supplies the house with it's power will be the grounding electrode system at the house the earth itself and the grounding electrode at the transformer. In my system, the NEUTRAL is bonded to ground in a 200 AMP service entry on a pole. This box has feed-through lugs. From there I have a three wire feed to a grounded subpanel(on the house) that I intended to isolate from the NEUTRAL. By binding the NEUTRAL to the GROUND at the subpanel I would in essence be bonding the two GROUNDS together through the NEUTRAL. Would this not create a problem? No. You have no utilization equipment at the meter location. Because there is not a 4th grounding wire run with the two conductors, wouldn't there be a difference in ground potentials? The potential difference of concern is AT THE CABIN. That is where you will use your lights/appliances/whatever. You want the neutral *at the cabin* to be as close to the potential of the physical ground *at the cabin* as possible. A difference in ground potential from the meter location to the cabin location poses no hazard - they are too far apart for you to be exposed to the difference. But a difference at the cabin between the neutral at the cabin and the ground at the cabin is something you can be exposed to. There is no utilization equipment at the meter location to be adversely affected by ground loops. You would be well served to read, understand and follow Mr. Horne's advice. Ed

Best Wishes, Attentively };-) Roy Q. T.

Objectionable Neutral Current ­ Section 250-24(a)(5).

A neutral-to-ground connection shall not be made on the load side of the service disconnecting means except as permitted for separately derived systems [250-30(a)(1)], separate buildings or structures [250-32(b)(2)], or meter enclosures [250-142 Ex. 2]. A neutral-to-ground connection at any other location will cause objectionable neutral current to flow on the equipment grounding conductor (conductive metal parts of the electrical equipment). This violates Section 250-6(a) and can create an electric shock or fires, as well as power quality problems.

Gentlemen, it appears from this that a neutral/ground bonding is permitted at the separate building's meter enclosure. It's apparently a bonding elsewhere that creates the hazard.

That is correct. Not only is it permitted, it is mandatory. Excerpting 250-32 (b) (2) (emphasis mine) "...the grounded circuit conductor run with the supply to the building or structure *SHALL BE CONNECTED* to the building or structure disconnecting means and to the grounding electrode(s) ..."

The word shall as used in the NEC denotes mandatory: "90-5. Mandatory Rules, Permissive Rules, and Explanatory Material (a) Mandatory Rules. Mandatory rules of this Code are those that identify actions that are specifically required or prohibited and are characterized by the use of the terms *shall* or shall not." (I emphasizsd the word "shall")

Ed

The neutral and ground must be bonded at the service dissconnect (and connnected to a grounding electrode). This is the "magic" point. The neutral MAY, and usually is, also bonded to the meter box. In the case of a PVC entry raceway that is how the meter box is grounded. After the service disconnect the neutral and ground "must never cross" (with exceptions).

Bud--

John Gilmer wrote:

What do you mean by "feed-through lugs"? (If there is no service disconnect at the pole the service disconnect is at the cabin and the neutral and ground MUST be bonded.)

Bud--