Grounding, Bonding & Parallel Paths

Follow the local building codes for this installation. Only one member of the CR4 forum knows where is this installation and they are not telling.

LOL!!

How true!!!

I have many doubts about your qualifications.

FOLLOW THE LOCAL AND NATIONAL CODES.

New 2015 NFPA 70E - nfpa.org‎

Without knowing where you are.................................................................this exercise is pointless.

Sorry, this installation is in Saudi Arabia. "Browsing" to the local codes you would see mix of references to US/NEC and UK standards. Most of the clients here now a days, especify using UK. But with some, especially with "aramco" projects, they still specify US.

Anyway, as to regards to grounding, what I know for US standard, it is only allowed to bond the neutral at the main, in this case the MDB. My question is, will this ensure operation of the correct branch breaker during L-G fault?

Also, for the bonding of building metal parts, does either US or UK specify single point of connection to the grounding system (ground ring). If I bond them at different location, won't there be an issue with "parallel paths"?

Sorry for the inconvenience. I hope you share your ideas and experiences.

Thank you.

You are reinforcing my doubts about your abilities with each new post.

Wiring Regulations - BS 7671 | Electrical Safety First

Saudi Arabia appears to be one of those special cases where multiple (potentially) conflicting standards and codes apply (as are some sites here in NZ). If you don't know what standards are applicable check the customer/tender documents carefully for clarification.

If you still don't know (and cannot get clarification from the customer), check the socket outlet pin configuration as it is likely a building with American sockets will be wired up to the US standards.

Make sure you clearly indicate in your proposals what standards you are using so if it is not what the customer wants it is caught at the very beginning of the project.

"Saudi Arabia appears to be one of those special cases where multiple (potentially) conflicting standards and codes apply (as are some sites here in NZ). If you don't know what standards are applicable check the customer/tender documents carefully for clarification."

That sounds to me like the country is not an enjoyable one to be a foreign contractor in. Even if the Tender documents say 'US Standards,' how do you know the inspectors won't be pulling out the books marked 'UK Standards' and fining you for things that don't match up? "Forget about what the proposal says, you should have KNOWN that this region uses the Ollieanstan standards for ALL buildings! It says so clearly in the Regional safety codes. What? You never went to the local Buildings and Construction office to review the codes? Oh, you went there and they said they did not know about any building codes? That was an obvious lie by those lazy buerocrats, you should have KNOWN the codes were on public display, in the third sub-basement, behind two locked doors and through the tiger cage."

Or you get different inspectors showing up each day, and they never use the same building codes for evaluation. Or worse, it's the SAME inspector every day, but his book of standards is never the same one as the day before.

ianeil18, did you work on The Address Hotel Dubai?

Have to agree.

One only link between ground and neutral.

Me neither. Someone is going to get zapped/killed if this gets put in.

Your schematic is not just wrong. This is a diagram for a disaster. Someone could very easily be electrocuted. An experienced professional is what you need.

First - I do not have an Engineering degree. Having said that, my background includes over 25 years of process evaluation and improvement in scientific Research and development. I have been a student of learning, hands on, with hundreds of PhDs in Engineering. I have also made discoveries applauded and accepted by those same PhDs. I simply collect facts, share them with those more experienced, and see where they lead.

National Code is a series of specifications developed at a point in time, based on the best know methods and current variables. Humanity has the propensity to modify the variables of every process and still stay within the desired outcome. With each change in variables, though, are introduced learning and additional possible outcomes. Any process that is not reviewed periodically, will introduce factors that impact the process outcome, simply because the initial specification did not, or could not, envision that variable - sufficient conditions did not exist. (As humanity ventures into space, this will likely play a bigger role in coping with change and the unknown.)

Having said that, National Code is a starting point for safety - a ground floor or baseline. It is also an economic floor as to what has to be done to insure a degree of safety. It does not address all variables, but simply provides a safety net in litigation.

Due to discovering a broken neutral (actually two separate breaks between the transformer and the secondary to my home that were undiscovered for over 5 years), the electrical path in my home was forced to use my Earth ground as a Neutral (US - Texas). Code demands that Neutral and Earth be bonded in the service panel. Earth is then linked to a ground, typically in a residence being an appropriate 8 foot grounding rod, driven into the soil. There is information available as to how to enhance the action and resistance of the Earth grounding rod, but all thought appears to relate to temporary and sporadic use - not continually for multiple years. Power companies are reluctant to insure their Neutral feeds from a residence are working properly. Repairs cost money, costs that can be delayed for a long time and forever. The upshot, though, is an unsafe product being delivered to the customer.

In my learning, the electrical charges shunted to the Earth ground, when a broken Neutral exist, seek the path of least resistance. If the copper plumbing underneath a home provide a path of least resistance, the electrical path back to ground then becomes the copper plumbing. This results in continual degradation of the copper pipes as molecules are continually stripped from its surface (pitting). This "pitting" can be enhanced by soil pH and the relative humidity of the soil next to the pipes. Eventually, the pressure of the water inside the pipes overcomes the ability of the pipe to contain the pressures. Pinholes develop, which enhance the saturation around the copper pipes, and the process cascades. This cascading results in interior flooding of a home and the required replacement of all copper under the slab that was linked through that water heater. I have a lot of copper pipe that can be tested in a lab to back up my learning.

Back to the grounding question. It is my observation that to be proactive in protecting safety inside a building or home, that resistance tests (Ohms) be conducted on the separate ground links at the service panel to insure that the primary earth ground (the closest tie to the service panel) has the least resistance in the entire network to insure it will be the path of preference for errant electrical charges. Due to the resistance of my copper plumbing being less than the grounding rod (present grounding rod correct according to all code), a plumber that was replacing pitted pipes was shocked to the extent where he could not release his grip from the electrified pipe. If not for his apprentice being next to him to knock him loose, he would have died. Turned out that the natural gas lines connected to my house were also electrified, as he was again shocked trying to climb out of the tunnels and tried to steady himself while standing up. The power company emergency response technician, who arrived 30 minutes later, measured 88 volts on my "ground". It should measure close to zero. The broken Neutral problem is well known (and not uncommon) in many circles, but ignored with threats of "you're fired if you talk about this outside this room".

I do believe you have posted most of this before on another CR4 blog. It rings a few bells with me.

As I believe I said at the time, if RCDs were also installed, the loss of the neutral connection would have dropped the mains immediately current flows via the earth.....

The plumber would not have been shocked. The danger with the gas mains would have been averted....

Having RCDs installed (Wiki uses this name for all of them, though in the US they are called by different names) brings with them a gigantic leap, of far more electrical safety in houses and offices around the world for the people (and pets!) there.

Not perfect, but FAR better. Touching phase still hurts..... But for most people, they will not die.

You would therefore have been "warned" about the neutral problems far earlier by the action of the RCDs, by probably not being able to actually switch power onto the areas affected by the neutral loss, but thereby bringing far more safely for all living beings (other than being a big P.I.T.A.!) on such premises.

Such RCD breakers are seemingly almost totally ignored by many people of quite normal, or even above normal intelligence. God only knows why.....

Though some countries have brought them into "new build" rules and regs, but still ignore the old build houses completely....even though it is a cheap and easy upgrade.

The OP should also consider having them installed as well, after correcting the wiring errors of course.....

I believe that just about all house/office "normal" electrocution (?) can be mostly avoided with working RCDs, correctly installed, when earth current is involved to some degree (depending upon the actual RCD used).

I do believe, that only a direct neutral to phase electrocution (no contact to earth) cannot be detected as far as I am aware by RCDs. That is my personal opinion at least. But this is a less likely form of electrocution anyway....

See here:-

Residual CurrentDevice

Even a small leakage current can mean a risk of harm or death due to electric shock if the leaking electric current passes through a human; a current of around 30 mA (0.030 amperes) is potentially sufficient to cause cardiac arrest or serious harm if it persists for more than a small fraction of a second. RCDs/RCCBs are designed to disconnect the conducting wires quickly enough to prevent serious injury from such shocks. (This is commonly described as the RCD/RCCB being "tripped".)

(My comment above does not apply to very high voltage systems, ones not usually seen in houses and offices.)

Andy Germany - you are correct and I thank You. In my home, I have RCDs (GFCIs) downstream (from the Service Panel) throughout the house (built 1992) that address wet areas. None of those GFCI receptacles ever tripped. If I understand you correctly, the first and main breaker should be replaced with an RCD so that it can react to an incoming failure of an open neutral? The situation here resulted from the power company Neutral cable insulation being damaged (nicked, whatever) sometime in the past 20+ years and that aluminum wire eventually disintegrating (electrolysis?) to create an open. Since this was a gradual transfer of the Neutral path role (which path has the least resistance) from the transformer to my plumbing, the signs were vague. In the months leading up to the plumbing leaks, I did notice that any appliance or tool that drew over 10 Amps (power saw, power washer, etc) would impact lights inside the house, but this would be recognized only id there were someone inside the house to witness the change - I was working in the yard, in the daylight, with that machine. This never resulted in the main breaker tripping.

Do I understand your advice correctly, that by utilizing RCD technology as the main breaker, when there is a switch from power returning to ground on the Neutral circuit to power returning to ground through the Earth ground of a building, that the switch in paths will be identified? If my understanding is incomplete, what would be a method of identifying when the responsibility of the Neutral was being shifted to a buildings Earth ground network. Any advice or recommendations to topic research are welcome!

GFCI plugs are a great safety feature, but quite temperamental when used with some motors (freezer, any "noisy" motor). The spikes created by some electrical equipment tend to trigger the GFCI. When that happens with food storage, replacing the GFCI with a standard plug is the easiest fix. Would not a GFCI (RCD) being used as the primary breaker be prone to trip when just about any electric motor with a starter downstream energized?

A current clamp will identify when plumbing is electrified, but this is kinda like only having a blinking light on the dash to indicate "gas tank empty".

The OP of this topic, in my understanding, is trying to understand how to enhance a building ground network to address recently learned variables. Yes, there are extra costs that are hard to justify to the bean counters, but perhaps a process can be developed to monitor these new variables over time?

On a single phase building, its probably better to have an RCD covering several circuits, but not all on one, though that will work, so that in the event of a trip, not all power is suddenly removed.

At night, that could be equally dangerous. Or at least have emergency lighting, they are cheap on ebay....

I live where 3 phases into a house are normal. I have one on each phase. They have never been tripped, except when testing....

You appear to not understand how a correctly installed RCD works, it "notices" any tiny difference between the current flowing in the phase and the current flowing in the neutral. Which should be identical (though some also might say, equal and opposite!)......

It then makes the assumption that the missing current is flowing somewhere else to earth, via a human body for example. And removes power, very fast, fast enough that it should not kill anyone, but still hurts, believe me....I KNOW!! But not at home!! At work!!

In your case, it would have tripped VERY fast when power was going via the earth.....assuming that otherwise, all wiring was to code and no "extra" links between neutral and earth....Just one and one only.

Having them in wet areas is a good start, they can be set to trip even earlier on a lower fault current.....

The only way to get a normal main breaker to trip is over current.

You still need over current protection, though there are RCD breakers that trip on either fault.

You asked:-

If my understanding is incomplete, what would be a method of identifying when the responsibility of the Neutral was being shifted to a buildings Earth ground network. Any advice or recommendations to topic research are welcome!

I cannot help you there, but some who know your area code here probably will. If you had had the RCDs already installed, you would have had RCDs tripping, warning you that something was wrong IF there was any error, as there was!!!......

Unless your installation is "clean" you will get tripping of RCDs....it can be very annoying I have heard.....but better safe than sorry.

Power leaking to ground will still be logged onto the power meter, you pay for that.....

I learned the hard way. I work on boilers Mfg and install. Got neutral to ground low voltage on a motor ,single phase 120v. Saying that I had to help to fix the problem and I found the fix. I also learn that the ground and the neutrals have to be tied in at the main panel.

If it's not what it may happen is that if you have a short anywhere in any circuit, it may ruin other circuits, burn controls are the most danger. In my case most experts wanted me to ground the neutral, but I refused their fix. I think you can do the same so the answer is: ground and neutral from the main panel. Note I'm in the USA. Using Uniform electrical Code. Regards.

Recently discovered and received permission to share the following, This is part of a safety training lecture regarding the purpose of Neutral and Ground in an electrical distribution - based on USA codes. It was an "Ah Ha" moment for me, as it was spot on for my situation. Easy to understand presentation, which was wonderful for me. This will be basic 101 for many of you, but as the author noted, it took him several years before he could define it in simple concepts for those who don't work with electricity daily. I hope some find this useful - I did.

https://www.youtube.com/watch?v=-n8CiU_6KqE

Mostly good, except who double earths the load? He appears to not understand that part exactly....

Which may be misleading for a beginner....

The installation diagram does not conform to British Standard 7671. It isn't a design. It's a potential disaster _{[sorry about the pun]}.

End of.

I guess he forgot to mention that (most of it) conforms to Canada, the USA and some parts of Japan, if I remember correctly. Not to the UK system, which blankets most of the rest of the world.....

I have come to the conclusion that the US 120/240 VAC system is actually in practise, more dangerous to life than the rest of the world's system with 240 VAC, Neutral and earth... Only one hot wire instead of two....

Maybe thats why the US system is not everywhere?

Thanks to all for their views and input. The critical understanding needed on my part, to address the root cause of the problem in my home, was discovered through the video. I needed to understand the role of Neutral and Ground, and what happens to the rest of the home electrical system when either becomes open. Applying US type code, when the Neutral is open at the first service panel, the Ground system becomes a sacrificial anode for the entire home electrical system. In doing so, electrolysis begins to strip away metal from the sacrificial anode. In my situation, the copper plumbing from the hot water heater under the foundation carried the biggest burden. Pitting began, especially where there was any change of water flow resistance (connections, bends, slight dents in the circumference of the pipe). This electrolysis accelerated degradation of the pipe, causing it to fail well in advance of its projected lifetime. This understanding will save me from having to hire a professional witness for court - a cost close to a year's salary!

The problems, the dangers generated and the damage to the copper piping, were all as a result of not following code, plus illegal and dangerous modifications to "bridge over" a broken neutral. Your own post (#9?) mentioned the crux of the problem here:-

Due to discovering a broken neutral (actually two separate breaks between the transformer and the secondary to my home that were undiscovered for over 5 years), the electrical path in my home was forced to use my Earth ground as a Neutral (US - Texas). Code demands that Neutral and Earth be bonded in the service panel. Earth is then linked to a ground, typically in a residence being an appropriate 8 foot grounding rod, driven into the soil.

You appear to feel that Texas code allows this (possibly?). "the electrical path in my home was forced to use my Earth ground as a Neutral (US - Texas)."

Luckily I don't live in Texas if what you say is true, but I do not understand what you exactly mean by forced.

It sounds to me as though an amateur, illegal modification was made to link neutral and earth in a position that code had not foreseen. In a wiring to code standards situation, if neutral was damaged/broken, code wiring would have stopped all current flow in your house....as it should have.....

So it was not "forced" it was "lead" by illegal cables or links or similar.

If code, perhaps Texas is trying to reduce the population size without using the electric chair, instead, the electric house!!

If you had had the problem correctly repaired when it started (you must have noticed! as you knew there were 2 breaks in the Neutral!!) to code specifications, none of the "follow on" problems could have happened, including copper degradation and giving a plumber a shock that could easily have killed him (from memory and from a previous post!).

In fact, there was the possibility to have killed someone from day one of the neutral break(s) and the "repairs" that did not follow code....you were simply lucky that it did not happen....

As I have mentioned many times, (here and elsewhere), if RCDs (or the local equivalent name!) had been in use, NONE of this would have happened, and a proper repair, 5 (?) years before, would have been needed to resolve the problems to such a state that would allow your house to have been safe(r) to use for everyone.

This would "have had" to have been to follow code correctly.

The REAL question is, have you learnt your lesson or not?

Saving the cost of an expert witness, would appear to be the least of all the problems seen......but you appear to feel its the best one. I don't think that an expert witness would have been a help anyway, in fact he might have put your head in the "noose".....

You will have to wait and see if the prosecution "expert witness" does it for you anyway.

Going against a prosecution expert witness as an amateur, is not something that I would recommend myself.......wait up!!

Losing a child or any loved one (or a plumber!) was high on the list for 5 years.....you were simply lucky......try seeing it as it is and was!!! Money isn't everything.....

The house has now been returned to code (one would hope!), at a significantly higher cost than needed 5 years before, plus you have a court case coming up, that may not go how you would like it to and some serious money may be needed for any fines imposed, correctly so.

Also, as the copper (earthed) was used as neutral incorrectly and dangerously, the degradation was due to that, a further extra cost would have been prevented.

So what was saved? Money was certainly not, and people's lives only by the grace of God!!

Remember, everyone must live by their own decisions....

<Unsubscribing in absolute disgust>

Andy - you make assumptions not in reality. I've only made discovery of what is within code. I did not modify my ground. it is to code. The home was to code when I purchased, Between the time I purchased my home and today, the aluminum Neutral cable, which was the responsibility of the power company, between their transformer and the secondary connection at the edge of my property that also connects underground to my usage meter, failed. It no longer supplied a return current path as contracted. Since it did not function, the return current path to ground was forced (path of least resistance) to my Ground, or Green wire circuit. The result was an eroding of my plumbing that resulted in financial loss. This may not be common in your neighborhood, but due to code differences, it is common here in the USA. It sounds like your response implies other than understanding alternate construction code. In the USA, the neutral and ground are bonded in the primary (main) service panel. If the neutral link fails between the transformer and the primary service panel, all current is forced to follow the least path of resistance to ground and migrates to "earth ground". The Earth ground is, according to code, all potential metal earth contacts under a structure. This includes gas lines, plumbing lines, and every metal to earth contact. There is a direct electrical ground line (green wire) run from one of the two water heaters input pipes (behind sheet rock) back to the primary electric panel, that also ties to my 8 foot buried, code ground rod about 8 foot from the primary (fuse box). Apparently, my underground plumbing provided less resistance and became a sacrificial anode. Regardless, it is not my responsibility to provide a sacrificial anode for the power company. I pay for that service. It was not provided, and I suffered financially. I'm simply trying to pass along to others information that places responsibility for damages were it belongs.

All discovery here was not immediate. I simply reflect what I have learned over the course of 7+ years. As one who lives on diminishing assets, I don't call the electrician when a bulb fails, I go into discovery mode. All of the discovery was on my own, as I have been unemployed for 8+ years, now have to rebuild my home, and am simply trying to survive in poverty created by elective government. Your response, like one other I have received from this forum (but not all) reflects a less than helpful and more of a "you probably don't know which side of a shoe to shine" response. I'm well above average and have partnered in patents and many microprocessor discoveries. The smart phone and streaming video included. I figure everyone has a bad day and can lash out on strangers, as long as there is an apology. Real men are not afraid to admit being human and incorrectly insulting others.