Easiest way to ground a computer?

She asked for a ground. That screw should be grounded. I said 'should'. It's up to her to have it tested, just like the cold water pipe. Ok? Now take a chill pill.

Reply to
Ron Tock
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Irresponsible to connect wall receptacle ground to a water pipe. A wet human in a shower, bath, or touching water in a sink is at greatest risk. And you would dump electricity into those pipes? Shame on you. It is safer to not ground at all rather than connect to water pipes. Even the code does not permit this type connection any more. The only electrical connection to water pipes is to remove electricity from those pipes. Never dump electricity into water pipes.

Numerous reasons to never connect AC receptacle ground to water pipes. Electricity in those pipes is more hazardous than an outlet without safety ground. Sounds as if previous owners replaced all two wire receptacles with three wire receptacles without the necessary safety ground. Therefore those screws would have no safety ground connection. These receptacles are only safe (and legal) if powered through a GFCI. And GFCI was one of two possible solutions provided in another post.

Meanwhile, any recommendati> That little screw that holds the outlet cover on should be grounded.

Reply to
w_tom

w-tom I realize that we may disagree on this but since the US NEC specifically requires the use of underground metal water piping as part of a building's grounding electrode system don't you think it would be clearer to say "interior metal water piping" when saying metal water piping should not be used as a ground for an electrical system. The code specifically permits the equipment grounding conductor that is installed as a retrofit ground to run to any electrode of the grounding electrode system vis..

[VII. Methods of Equipment Grounding 250.130 Equipment Grounding Conductor Connections. Equipment grounding conductor connections at the source of separately derived systems shall be made in accordance with 250.30(A)(1). Equipment grounding conductor connections at service equipment shall be made as indicated in 250.130(A) or (B). For replacement of non?grounding-type receptacles with grounding-type receptacles and for branch-circuit extensions only in existing installations that do not have an equipment grounding conductor in the branch circuit, connections shall be permitted as indicated in 250.130(C). (C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: (1) Any accessible point on the grounding electrode system as described in 250.50 (2) Any accessible point on the grounding electrode conductor (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates (4) For grounded systems, the grounded service conductor within the service equipment enclosure (5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure(copyright 2002 National Fire Protection Association)]

The point you are making is quite valid. The interior metallic piping system must not be used as an equipment grounding or bonding conductor. Having said that I have to take issue with the statement that "any recommendation to connect safety ground to cold water pipes only creates a potentially greater hazard." I realize that this is a fine point but I believe it is important enough to be clear. The US NEC does not offer any option. When an underground metal water pipe that is twenty or more feet in length is available on the premise then it must be used as a grounding electrode vis..

[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. (1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system. (copyright 2002 National Fire Protection Association)]

Please note how carefully the Code Making Panel differentiated between interior and underground water piping.

-- Tom H

Reply to
HorneTD

One plumber need only replace copper pipe in plastic. The human taking a shower or bath is then at extreme risk if the wall receptacle safety ground has been connected to those pipes.

The connection from breaker box to cold water pipe is required by code to remove electricity from that pipe. There is no way that connection can be reliable to a wall receptacle because copper pipe is often replace with plastic. The only way a wall receptacle can make a safe connection to the water pipe is to make the connection adjacent to where that water pipe also connects to breaker box. The connection authorized by NEC article 250.

All of this being completely irrelevant to the earth ground electrode system. Wall receptacles are safety grounded. That means they must connect to breaker box bus bar. Earthing electrode or a water pipe in contact with earth does nothing to provide a safety ground to that wall receptacle.

In places such as Canada, grounding to water pipes is still permitted by code. But the point is (and I believe HorneTD is making the same point), that wall receptacle must be grounded by a method that cannot be 'accidentally' compromised. Leaving the wall receptacle ungrounded is safer than putting a human in bathtub at risk.

Aga> w-tom

Reply to
w_tom

Hi Tom,

Can you explain briefly (technically if needed) why earthing is not grounding?

My understanding is there are 3 wires, hot, neutral, and ground. Hot and neutral connects to the utility lines, and ground connects to the ground. Is it the 'difference' between one ground and the service panels' ground that might be causing some problems?

You mentioned "A safety ground must connect the appliance ground prong to circuit breaker box safety ground - the neutral bus bar", if I am understanding this correctly, you are saying both hot and neutral gets wired to the neutral line? How can this be right? Won't the ground then be constantly hot?

If I connect the ground of a receptacle (using a proper ground wire) to an actual earth ground (and assuming the connection is good, not flaky), what exactly is the problem? (I understand the concern about connecting to water pipes and people taking bath....)

Sorry if these questions are too naive for all your troll sensitive posters. ;) I am just trying to understand this, so if you don't want to answer, just don't say anything.

Thanks.

Raymond

Reply to
nospam.home

Earthing is grounded. Or I should say: "earthing" is UK usage for what in the US and Canada is called grounding. To say that something is earthed or grounded implies that it is electrically conductive to planet earth, which for these purposes we pretend is an infinite sink for electricity. (In electronics where there is no such thing, the word "common" is used instead. The "ground" in your car's electrical system is a "common", since there is no conductance to the earth.)

Quite right, in a normal North American 120 V circuit or a normal 240 V circuit elsewhere. Older wiring simply omits the ground.

(In official code books, the neutral is called the "grounded" conductor and the ground is called the "grounding" conductor. Let's not do that. Grounding is also called "bonding" because of how all junction boxes are supposed to be connected to it.)

Neutral and ground are connected together at - and only at - your main service panel, and that connection is also connected to ground in the form of a buried rod or something appropriate to the local conditions.

And in fact, I believe the neutral is also connected to a buried ground rod at the transformer where your power is stepped down to 120 V from whatever higher voltage the main lines are at. Others may correct me on that.

Not hot and neutral certainly, but ground and neutral yes, which is probably what you meant.

All the grounds from each circuit go to the ground bus (not the neutral bus) in your main panel. All the neutrals from each circuit go to the neutral bus in the panel. Plus, the neutral bus has one connection to the ground bus, and the ground bus has a big wire going to your buried ground rod.

With these connections in place, neither neutral nor ground can ever be hot because they have a (effectively) zero-resistance path to ground. "Hot" you must understand is a relative term; one thing is electrically hot relative to another. Normally the reference point is the ground. Circular but self-consistent.

If your neutral bar became disconnected from ground AND from the utility's neutral feed, then all the neutrals in your house would be hot. Things would quit working because the current that feeds them would have no path to ground. (In fact the "other" hot leg of a North American two-leg 120/240 service complicates this, but let's ignore that.)

If your panel's ground bar became disconnected from ground AND neutral became disconnected from the utility, then all the metal chassis of all your appliances would become hot, via their ground connection. That's really bad for anyone touching such a chassis while they're in good contact with the earth. If you're in slippers on a carpet you're probably ok but if you're loading dishes from steel sink into a dishwasher, you're in trouble.

As I understand it, IF you did this "right" and IF the connection is good, then you're ok, and as I understand it, historically electical code permitted isolated grounds like this as a means of dealing with legacy two-prong wiring. But others may correct me on this.

It's the weakness of the "IF" that's the problem. The trouble begins if your connection is imperfect and has non-zero resistance. Then if your chassis becomes hot owing to an internal fault, current will flow through your makeshift ground, maybe not enough to blow the fuse but maybe enough to overheat your ground wire. And someone near the ground wire, or even standing on the earth over your buried rod, may be a better path to ground (perhaps their other foot is in a puddle, or they're leaning on your meter box, which is well grounded) and the current will flow through them.

And suppose you've got another circuit "grounded" on the same rod, so now the chassis of that appliance is made hot because of the fault in the first one.

So the answer is that the proposal is not prima-facie dangerous, in that if executed perfectly it would work. The problem is that it's so hard to execute well it will certainly result in a half-assed mess, so a better approach is not to try. Code now says that a home has one and only one connection to ground, via the ground bar in the main service panel. Even subpanels in the same building - even outbuildings, with some restrictions - are supposed to have separate neutrals and grounds and no local ground rod.

I'm confident that my responses will draw at least as many flames as your questions would.

Chip C

Reply to
Chip C

It does not have to be what either of us believe is smart to be what is required by law. If the US National Electric Code (NEC) is adopted by reference as law in your location then you have to use any underground metal water pipe that is three or more meters in length as part of the grounding electrode system. It does not matter if in your or my opinion that imperils someone in the shower or bath. You have never to my knowledge accepted the point that whether the water piping in the building is metallic does not effect the requirement to use that underground metal water piping as a grounding electrode. That underground metal water piping is for many homes the only effective earth grounding electrode. I have been doing electrical work for nearly forty years and I have never encountered a municipal water system with a resistance to ground of more than twenty ohms. During that same time I have never had a single or double driven rod electrode of ten feet per rod or less measure less than fifty ohms. The best grounding electrode is going to be the one that puts the most conductive surface in contact with the earth at the deepest level. For many buildings that is the metal service lateral of the water supply.

-- Tom H

Reply to
HorneTD

Thank you for your detailed reply Chip. It is very helpful.

I am still a bit fuzzy about the ground bar and neutral bar being 'connected' at the service panel. Won't all electricity just goes to the ground in that case? I know it sounds silly, but what's the difference between connecting the ground/neutral at the panel vs connecting them at the receptacle? a wire is a wire right?

I suspected the answer to "why only one ground/grouding rod" is the big IF part in my post. Thank you for clearifying that part.

let me ask another (not a troll!) question, in many areas, redundancy is good. if one fails, the other still works. isn't having two properly done ground rods better than one? If one fails, then the other should still work? having the code calling for one and only grounding to be done at the service panel, then the whole system will be depending on that grounding work correctly. The probability of one fails is much higher than the probability of both fails right?

I mean redundancy is why I backup my data to CDRs. ;)

So if I understand it correctly, the grounding for the satellite dish for example, is to connect the metal part of the dish to the ground bar in the main service panel via a proper ground wire? not to the earth right under the satellite dish (or roof) which I can dug a hole and bury the bare copper wire that came with my satellite install kit? And the reason being the ground at the servie panel will most likely provide less resistence than my bare wire?

Thanks again.

Raymond

Reply to
nospam.house

Are there any down sides to replace all the outlets in one's home with GFCI's? Would refrigerators cause it to trip under normal operations?

Thanks.

Reply to
nospam.house

Expense, for one. Nuisance trips, for another.

They can, yes. And that's bad, if you don't catch the problem soon enough.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

Reply to
Doug Miller

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Reply to
John Doe

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Reply to
John Doe

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Reply to
John Doe

Says a troll who is so full of it, he has to post x-no-archive.

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Reply to
John Doe

Raymond

The biggest fallacy in the common understanding of electricity is that electricity somehow seeks out the earth. That is simply untrue. Current will flow from a point of higher voltage to a point of lower voltage if there is a conductive path between them. Given a high enough voltage almost anything will serve as that conductive path. Lightning through the air is one example of this. For general public electrical safety education purposes it is best to think of current as trying to return to it's source rather than the earth. If one leg of the source is grounded and the circuit is grounded at other points, as it is in the US multi grounded neutral system, then the earth will carry part of the current back to the source. Current does not take the path of least resistance back to it's source it takes all available paths back to it's source in proportion to the resistance of the available pathways.

In many main electrical panel enclosure cabinets; that are functioning as the Service Disconnecting Means enclosure in homes; the neutral buss bar and the Equipment Grounding (Bonding) buss are the same buss bar. In some brands of panel, GE comes to mind, that buss bar can be divided in half and used as two separate buss bars. In other brands, such as SquareD, if you need a separate ground buss you add it using a buss bar kit you purchase from the vender. The US NEC requires the neutral conductor of the supply must be grounded to the earth somewhere between the demarcation point; that separates your wiring and the utilities wiring; and the neutral terminal of the service disconnecting means. This connection is made to make the installation somewhat resistant to the damage that would be caused by lightning and other high voltage transient current flows. Lightning, you see, is indeed trying to return to earth and the opposing atmospheric air mass because that is the source of the current. The US NEC states it this way.

[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.

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.(copyright 2002 National Fire Protection Association]

So we ground electrical systems to limit the voltage to ground because that reduces the likelihood of destructive current flows between the systems components and ground or earth.

Grounding does not play much of a roll in the actual functioning of your homes electrical system. Aircraft in flight have a perfectly functional electrical system including regular AC outlets that can be used to power electric shavers and sometimes passenger owned electronic devices such as lap top computers. For ease of design, construction, and maintenance such systems have to have a reference point that can be considered zero volts. The aircraft's frame is used. Obviously we cannot ground anything on an aircraft in flight but we still must bond all of the non current carrying parts of the electrical system back to the source of supply, just as we do in a buildings electrical system, and to the aircrafts common point in this case the airframe.

This bonding; the term of art is presently equipment grounding but there is a proposed amendment that will change this to equipment bonding; is done to provide a low resistance return path back to the source for current which has escaped the normal current carrying conductors thus allowing it to complete it's circuit in a non dangerous and non destructive manner. The US NEC describes the purpose of this deliberate interconnection of all non current carrying parts of the electrical system this way.

[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.

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.

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. (copyright 2002 National Fire Protection Association)]

So lets review what we are trying to do. We want to limit the voltage to ground so as to avoid destructive and dangerous current flows between the system and the earth. In North American practice the techniques used to accomplish this are called grounding. We also want to provide a low resistance pathway back to the source so that any escaped or faulted current can return to the source in a non dangerous and non destructive manner. Those techniques are called equipment grounding but soon to be called bonding.

As to how many different ways you can ground the system the US NEC requires that any of the electrodes in the list that are present on the sight must be used to construct the 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.

A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.

The metal frame of the building or structure, where effectively grounded.

Concrete-Encased Electrode. An electrode encased by at least 50 mm (2 in.) of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 6.0 m (20 ft) of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (½ in.) in diameter, or consisting of at least 6.0 m (20 ft) of bare copper conductor not smaller than 4 AWG. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.

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.

Rod and pipe electrodes shall not be less than 2.5 m (8 ft) in length and shall consist of the following materials. (a) Electrodes of pipe or conduit shall not be smaller than metric designator 21 (trade size 3/4) and, where of iron or steel, shall have the outer surface galvanized or otherwise metal-coated for corrosion protection. (b) Electrodes of rods of iron or steel shall be at least 15.87 mm (5/8 in.) in diameter. Stainless steel rods less than 16 mm (5/8 in.) in diameter, nonferrous rods, or their equivalent shall be listed and shall not be less than 13 mm (1/2 in.) in diameter.

Plate Electrodes. Each plate electrode shall expose not less than 0.186 m2 (2 ft2) of surface to exterior soil. Electrodes of iron or steel plates shall be at least 6.4 mm (1/4 in.) in thickness. Electrodes of nonferrous metal shall be at least 1.5 mm (0.06 in.) in thickness.

Other local metal underground systems or structures such as piping systems and underground tanks.(copyright 2002 National Fire Protection Association)]

About your satellite dish. The reason that it is so important to bond your satellite dish to the buildings electrical grounding electrode system rather than to a separate isolated ground rod is that separate ground points can have a difference of potential or voltage between them. The higher that voltage is allowed to become the more likely a dangerous or destructive current flow becomes. There is nothing wrong with having a ground rod directly under the dish. I would in fact argue that it would be best practice to install one there. The critical thing is to bond the dishes rod to the rest of the grounding electrode system so that they all behave electrically as a single electrode.

That is more than enough for one posting.

-- Tom H

"Can you skin Griz?

Well skin that one pilgrim and I'll bring you another."

Reply to
HorneTD

A GFCI on a refrigerator is actually considered a human safety threat. Not from electricity. Threat to humans is from food poisoning. The human might not know how long or when the electricity had tripped off.

Bedrooms now must use a different type of GFCI on all wall receptacles. This because fires from things like extension cords have proven to be a more serious threat. My personal recommendation is to put an AFGI on the outlet that lights any live Christmas tree. Others have demonstrated how a Christmas tree fire leaves the occupants less than five minutes to get out.

The downside to GFCIs is nuisance tripp> Are there any down sides to replace all the outlets in one's home with

Reply to
w_tom

You are confusing an underground water pipe replaced in plastic with something different from what I am discussing. Plumbers sometimes replace *interior* copper water pipes with plastic. That would make the bathtub 'hot' if wall receptacle was safety grounded to cold water pipe that was 'fixed' by the plumber.

Again, earth ground has nothing to do with the earthing electrode. They serve different functions. But dumping electricity into a household cold water pipe system - pipes inside the house - is unacceptable today because interior pipes are replaced in plastic.

BTW, > It does not have to be what either of us believe is smart to be what is

Reply to
w_tom

A lot of the rules are for what happens if something goes wrong. If you analyze the rules based on normal operation you get a lot of "what's that for? that doesn't do anything! that's redundant! that carries no current!" But many years of analyzing electrocutions, fires and plain old power failures have given us code rules that cover a vast array of what-ifs.

HorneTD's response included some excellent fundamental points: electricity takes ALL routes back to its source, and the US and Canada use a multi-point grounded neutral system in which the neutral is grounded at the power company's transformer AND your house. This means that the ground AND the power company's neutral are both ways to complete the big circuit back to the generator. I believe that this fact has implications that I don't really understand, again in the realm of things that can go wrong in odd circumstances.

Redundancy can bite you back. In the case of grounding there is a phenomenon called "ground loop" caused by natural and other phenomena (soil chemistry, induced voltages from radio waves, earth's magnetic field) which can mean that one point in your yard is at a different electrical potential than another. That means that your two ground rods are at different voltages and a current will flow from one to the other via your ground wires. This can induce a voltage on your ground wires, exactly the opposite of what you want. Effects could range from nothing, to minor static shocks when you touch plumbing, to interference with radio and tv reception and other electronic devices, to constant low-grade currents that promote corrosion in plumbing or structural steel pieces.

"Verily, he who would be wise sayeth: Put not all thine eggs in one basket; but I say to you, he who divides his eggs among baskets has scattered his fortune to the winds, and knoweth not what he hath and hath not; and I say to you, he who is truly wise shall put all his eggs in one basket -- AND WATCH THAT BASKET!"

I'm going to defer to HorneTD's post for this one.

Any discussion of grounding really ought to mention lightening, too; but that's a big complication. It helps to remember that lightening protection, like grounding for masts and lightening rods on the roof, is never aimed at conducting lightening "safely" to the ground, since that would require conductors the size of your arm. It's all aimed at draining off static charge that would otherwise accumulate and attract lighting by providing a path of ionized air.

Chip C

Reply to
Chip C

HorneTD has provided good and detailed descriptions of grounding. I will describe the same thing from a different perspective. Take three D batteries (ie inside a flashlight (torch in UK)). Each 1.5 volt battery adds to apply 4.5 volts to a light bulb. Which part of that circuit is the ground? Top of topmost battery? Bottom of bottommost battery? Select any point. Ground can be arbitrarily defined.

But what is the voltage between topmost battery and earth? Undefined. No connection exists. Voltage could be anywhere from 0 to maybe 20,000 volts. Now we earth the bottommost battery. Topmost battery is 4.5 volts above ground.

Suppose we also have inside that flashlight a 1.5 volt battery. Convention is to connect 1.5 volt lamp to top and bottom of bottommost battery so that both lights share one common point. Arbitrary common point - even if it was not connected to earth - would be called ground. We will call this light bulb ground.

So now we have defined two grounds. Light bulb ground and earth ground. We have put both grounds at the same point.

Let's move the earth ground wire to a point between two other batteries. Now earth ground is not the same as light bulb ground. We still have two different grounds. This time two different grounds are at different locations on the circuit.

Wall receptacles must connect back to the neutral bar inside the circuit breaker box where power originates. This "safety ground" must be sufficient to trip a circuit breaker. We just happen to (for good and well proven reasons) connect building's earth ground to this same point. A concept is called single point grounding. Done this way much for the same reason that stereo components interconnect using single point grounding (which is a but another ground).

Earth ground and safety ground are two different grounds. They share common wires. But they remain different grounds with different purposes.

Why is a building's earth ground so important? The neutral wire inside the transformer had failed. The house also had no earth ground connection. To get back to that transformer ground, household electricity used a gas meter as a neutral wire connection. Fortunately no one was home when gaskets failed and the house exploded. Just another reason why earth ground is so important. It does nothing until that rare time when it is really needed.

Too many instead will say the lights work just fine without that ground. Therefore that ground is not necessary. Same thinking that killed seven Challenger astronauts and seven Columbia astronauts.

C> Can you explain briefly (technically if needed) why earthing is

Reply to
w_tom

w_tom wrote: > You are confusing an underground water pipe replaced in > plastic with something different from what I am discussing. > Plumbers sometimes replace *interior* copper water pipes with > plastic. That would make the bathtub 'hot' if wall receptacle > was safety grounded to cold water pipe that was 'fixed' by the > plumber. >

If you would only add the word interior before water pipe when making statements such as "The connection from breaker box to cold water pipe is required by code to remove electricity from that pipe" There would be no disagreement between us. My concern is that some will see your statements as a reason to not use an underground metal water pipe as a grounding electrode. My other problem is that the US NEC specifically allows a retrofit EGC; i.e. bonding conductor; to terminate in several different places. You always state as an absolute that it must terminate at the supplying panel's ground bar. That may indeed be best practice but your insistence on best practice instead of code compliance will deter the installation of retrofit grounds as specifically permitted by the US NEC vis..

[The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: (1) Any accessible point on the grounding electrode system as described in 250.50 (2) Any accessible point on the grounding electrode conductor (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates (4) For grounded systems, the grounded service conductor within the service equipment enclosure (5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure]

-- Tom Horne

Reply to
HorneTD

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