Grounding Rod

Let me try to break the news gently: lightning goes wherever lightning bloody wants to go and doesn't give one hoot in Hades about what we think it is supposed to do. However, it does appreciate any and all efforts on our part to lead it to ground as directly as possible. Considering that lightning currents can exceed 200,000 amps through a potential difference of a 100 million volts (up to a billion volts very large positive strokes), leading it back to the 'source' (presumably a power substation) is a very, very, VERY bad idea.

thanks!!

Just a note regarding lightning protection systems: you want the lightning-protection conductors to have as much surface area as practical. Why? Lightning contains a great deal of high-frequency components well into the VHF band. Where DC and low-frequency currents tend travel through a conductor's bulk, high-frequency currents tend to travel very near the surface only, due to skin effect, and so you want the surface area to be large to conduct as much of this high-frequency current as possible.

This is why you see straps used in such systems instead of round conductors. Round conductors are a bad idea because they have a minimal surface area/volume ratio. As a result, if the high-frequency components meet too much resistance in such conductors, these currents can arc from the conductor to nearby conductors which present a lower impedance at these frequencies. Not good. Flat and wide is the way to go.

That's interesting. Where do the high frequency components come from? How does static electricity generate any frequency at all? It must be a by-product of the ionization of the air or something.

Arcs generate copious amounts of RF. Run a transistor radio near an arc welder, for example. A lightning stroke is a very complex beast. It doesn't propagate in a nice, smooth pulse at the speed of light, but as steps. Overall it travels around 100 km/s.

And speaking of pulses, any current having a duration less than eternity has AC components; the faster the pulse, the more amplitude its high-frequency bits 'n' bobs. As the stroke progresses, each step is a fast pulse. Hence, lots of high-frequency components. Copious amounts. The high-energy RF content typically peaks around 60-70 kHz, but the total bandwidth extends into the VHF.

There is a very good listing in Wikipedia that explains all.

All voltages are relative to something and for practical reasons in electrical power distribution, the ground is used as a reference point.

In certain applications cases like tram lines and single wire supply in the country, the earth is also the return path.

In more conventional situations, 240 volt AC is just the difference between the active wire and the neutral, and without a grounding connection the neutral could float at "any" voltage level with the active wire being just being 250 volts on top of that.

If the neutral floated very high for whatever reason, that which insulated the circuit from ground would have to be so much better, and in the event one touched a wire (with your feet on the ground) so much more dangerous.

much appreciated.

Static Electricity (Direct Current) travels from Negative (Earth) to Positive (Clouds),in most instances. You are correct that the current must travel back to the source in a closed circuit; however, Static Electricity is a build-up of opposing charges. The catastrophic discharge results from the dielectric breakdown, between Earth and Clouds. To be most effective, the ground rod must be connected to the highest point, usually a tower. The grounding rod helps eliminate a catastrophic discharge by draining the charge from earth to cloud.

Thanks! So if I understood correctly, the sole purpose of grounding rod is to protect the equipment against lightning?

One thing more, if I don't connect grounding rod, wouldn't it be a lot safer as I won't get a shock even I touch live wire standing bare footed as the circuit through ground won't exist (open circuit)?

as stated in my reply the supply authority neutral in most circumstances is bonded to earth as well so there is still a very good chance of getting a shock but the resistance through the ground may reduce the amount of shock you get if your lucky

So my point is, if there is no grounding rod at either side, and equipment is energized and I touch it, nothing should happen to me as the circuit is not complete (the Earth is isolated completely)... at least as per my understanding :(

Theory and reality can be totaly different. It's impossible to have 100% effective insulation to prevent all leakage currents. You shouldn't bet your life hoping that everything's perfect. Even if it was, it probobly wouldn't stay that way for long.

Is this a Charles Darwin award waiting to happen?

Not really, in fact, grounded equipment, might actually sustain far worse damage entirely due to the grounding. But who cares.

The idea of a grounding rod is to link the ground frame of any electrical equipment to the planet earth.

Just to make it safer for the sensitive (easily damaged!) humans who might use that equipment.

Without that "clamp", the frame could easily soar to voltages similar to the mains itself, with respect to planet earth, and anyone touching both might die!!

Many years ago, (1983) I installed a W.U.M. (washing up machine), on a 220VAC grounded socket- I was sweating and as I plugged it in, my hair brushed the frame (white goods) and I got a shock.

I was at ground potential.

The earth pins in the socket had been painted over and the WUM frame was unearthed.

I checked the insulation of the machine and it was over 10 MOhms, so I was in no big danger, but I surely felt that!!!

After cleaning of the paint, problem resolved.

Did that make sense for you?

Really you need to go and study electrics, not including high school, I spent around 12 years studying and probably there is a lot I don't know, but I simply then look it up, but you never, ever stop learning!!

"I know what I don't know!!"

<<Without that "clamp", the frame could easily soar to voltages similar to the mains itself, with respect to planet earth, and anyone touching both might die!!>>

If the frame or neutral point of generator is not connected to Earth at all, why would it matter if potential of frame rises as the circuit won't be closed (open circuit between generator and Earth).

The mains is earthed all the way from the power station.......by you touching phase and being in contact, even if not a 0 Ohm contact, with earth, you complete the circuit......Try it!!!

Thats why it not recommended to do this.....and why RCDs are a must!!

Okay I get. Let's talk about a portable generator. Like the ones commonly used in construction.

It's 625 KVA, 3 PH, 380 V, 60 hz generator. As advised by the manufacturer (CAT), a grounding rod has to be driven. I can't see any advantage another than protecting it from lightning.

To me it's seems safer not to connect generator to "The Earth" so in case of fault at equipment side, the circuit won't be complete.

You need to forget lightning, as I have previously posted here, its not really important, unless of course you have above the generator a pole, grounded, to attract lightning in the first place....

Which I personally have never seen done.....but its possible.....

The ground rod is to safeguard human beings.

Adding an RCD, improves the safety dramatically for them too.

Alright. Thank you for taking out time to reply. Much appreciated.

A "grounding rod" is meaningless unless you know what it is you're grounding. Everybody knows what a grounding-rod is, but what you connect to it makes all the difference. Are you grounding it as a "return-line" or as a "leakage current drain-line?" Also, "at equipment side" is meaningless unless you know if it's the supply equipment or the load equipment.

I was talking about grounding the neutral point of the star connection of the generator. I didn't want to drive a rod at all and connect it to the neutral point.

What seemed logical to me was to take the grounding conductor from the neutral point of the generator all the way to the equipment's grounding terminal.

Excluding the grounding rod seemed safer as it would completely isolate "The Earth" from the system. Meaning, even if live wire was exposed to equipment frame, the current wouldn't find its way back to generator via "The Earth."

What seemed logical to me was to take grounding conductor from neutral point of Generator all the way to the equipment's grounding terminal.

NO NO NO NO!!! That's a good way to find out if there is a heaven or hell.......

The neutral ground link is made at the source. Two different cables are lead away from this point, one called the neutral, one called ground.

Colours of insulation should follow code for each cable, allowing the installer to know which wire is which.

A phase wire generally goes with, so you have three wires insulated from each other, each one coloured differently to tell you what each is, in a 3 wire cable.

The ground is also attached to a ground spike at the power source, following local code requirements, so that machine ground and planet earth are the same potential = 0 Volts (hopefully!)

The neutral is used with phase to supply and return power to equipment. The ground is attached to any frame of anything that is not double insulated for safety reasons...

Here is a scenario for you if you don't have the earth to neutral bonding at either end generator or final circuit.

What If without you knowing it has happened, your gen set insulation breaks down some where in its windings, say for arguments sake close to the starpoint / neutral making it's frame the same potential as neutral & the frame has become grounded for some reason like it's been raining or is in a wet area or something is touching its frame resting on the ground & you are thinking no it's all isolated so I'm safe & the insulation in an appliance breaks down making it's case active potential & your using it. Or even the other way round the genset becomes active potential & the appliance becomes neutral potential will you still be safe.

I know these are a lot of what if & maybe situations & might be a 100 to 1 chance of happening wouldn't you prefer to have some sort of safety protection in place just in case it does happen?

Many things in life happen without us knowing in advance they will happen so we use safety practices & take action to help prevent them as best we can. Just like using a safety rope while your climbing up high to protect you just in case a strong wind blows & you loose your grip. We can't all be superman & be indestructible.

I must be missing something here, what you describe is close to what is "designed" to "be" in a portable generator. Normal business......tell me why that is dangerous please.

Can you maybe pick apart your comment and make it simple to understand what you are thinking of.....

As written, I see no obvious problem, and if an RCD was also correctly installed and there is a leak to ground from phase that "bypasses" the neutral in any way, the RCD will immediately drop the supply, rendering it safe and showing to the operator that something is wrong....

Remember, in a 3 phase alternator, the star/neutral point NEEDS to be connected to ground AT A SINGLE POINT, as near to the star point as possible.....less cable resistance between them.

After this point, the phase supplies the power to th load and the neutral carries the return current from the load.

If an RCD is installed, it monitors both currents (phase neutral)to see that one is as near as possible exactly the opposite of the other. Any "leaks", that is current diverted away for any reason, will cause the RCD to drop the supply completely.

Especially leaks via the earth cable.

RCD Drop current varies by type/setting and speed of disconnection also can be variable, but for the human, you can consider them instant.....

My apologies if what you wrote has any useful values, but I read don't see it at this time.

Please rewrite. If you wish.....

The statement "After this point, the phase supplies the power to the load and the neutral carries the return current from the load.", is not necessarily true.

Depending on the load, the source/return wires can both (or 3, if 3-phase) be non-neutral. 120vac uses a neutral, but 240vac does not.

Even if the generator's star-point is grounded to frame, it's still safer to also ground frame-to-earth to ensure a short travel distance. If the load-center is also grounded to earth, you don't rely on a lot of long cables/connections that can go bad or have a large voltage-drop. Some faults can be deadly without tripping any breakers.

You cannot count the ground wire as being the "neutral" wire. If 3-phase uses a neutral, then it will be a fourth wire besides ground (ground being a fifth wire). If 240vac uses a neutral, it will be a 3rd wire besides ground (ground being a 4th wire).

And vice-versa: you cannot count the ground wire as being the "neutral" wire. It's strictly for safety.

I have never ever said that. (At least not intentionally!)

You may have understood wrongly what I wrote, or I did not write it specifically enough, so please post the Post # where I wrote/you read that, as I must offer a correction immediately.

Thanks in advance.

For the OP.

3 Phase

Although the ground wire and the neutral point are at the beginning linked to each other, as close to the neutral point as possible. They MUST be regarded as two separate wires after that, doing two separate jobs, in the same cable of course.

So "usable" 3 phase here for example, comes into the house as 4 wires, 3 x phase, 1 x neutral. The neutral is bonded to a heavy earth connection, that must be buried in the ground at one end, it must also achieve certain parameters of resistance etc etc., as well as being linked to each socket and all plumbing in metal piping.

Portable Single Phase Generator

The manufacturer (here anyway) decides/marks one side of the two output wires as neutral.

He bonds this to the frame of the generator.

He usually/should recommend that an earth spike be used (maybe one is supplied!) from the frame of the generator. Sadly many do not bother......

Also, few have an RCD installed by the manufacturer (though I have not examined any very new ones lately, hopefully that is changing!)

For the record, my house in the UK was built around 1450, before the USA was "officially" found! But from 1976, it got completely rewired by my Father and I and a RCD of the type then usual, installed.....they have improved since then I am told....

In many areas of the world, there are still many older homes without such safety features.......

Even my caravan has one!!!

Naturally my house has three.....

Puh-tay-toe, Pah-tah-toe, we're both saying the thing. the words might different/strange, but it means the same.

We were speaking English first, by the way....... Before 1492!! Like my house!!

The OP is referring to a situation where the neutral is not bonded to the earth of genset including the frame of the genset with no earth electrode in the ground so as to completely isolate the electrical system from earth & remove the earth from the circuit completely saying wouldn't this be safer.

My reference is if you don't have the bonding & earth electrode, then the failure in the genset happens, it then causes the potentially lethal situation to appear without your knowledge with a fault in an appliance that can have the opposite potential.

Your saying "IF an RCD is correctly installed"

The OP does not refer to or state there is any RCD device attached to the system & with a portable genset there is rarely if ever an RCD installed usually just an over current device with a socket to plug into.

If the OP doesn't understand about neutral bonding do you really expect him to understand about RCD's

You wrote:-

Your saying "IF an RCD is correctly installed"

You appear to have missed/overseen some important points. Let me explain:-

1) I had previously posted a link for the OP to the Wiki page for RCD devices. This link:-

http://en.wikipedia.org/wiki/Residual-current_device

2) I had also already mentioned them several times and exactly how they work, like on these posts for example:-

Posts # 41, 31, 29, 25

How many times do you yourself need to see/read something before it "sticks"? Do let us know please? Maybe I have simply not realised just how long some people need to understand something maybe?

Also, you appear to have missed another point too, I was simply trying (with so many of my posts mentioning it, not counting other people's posts) to "EDUCATE" him into getting one or more installed for good logical safety reasons.

Because if he had one or more correctly installed, some of his "wiring ideas" would have simply (and correctly) removed power!!!

RCDs are cheap and relatively easily to install by an electrician......its not rocket science.

Do you have your family protected by such units in your house/apartment by the way? Be honest!!

I know many simply do not care either way, sadly!! That is till someone is injured or worse.....

my replies were purely addressing his question of why have the earth electrode & neutral bond, you were going off on a tangent into other technical discussions of the safety of RCDs. They are not mentioned by the OP or in other peoples posts & would be considered off topic as they have no bearing on the topic.

If there was no earth bond & electrode They would be ineffective without any bond of the neutral to earth & no electrode in the situation he describes, as the only fault that can occur in that situation with the supply completely isolated from earth would be between active & neutral & no path for any fault current to go to earth.

Your condescending comments about my person were not warranted I am a tradesman electrician with over 35 years in the industry & understand the benefits of RCDs the cost & ease of installation. I have installed many even as far back as 35 years ago in commercial & industrial situations many years before they had started using them in domestic situations in Australia.

Engage a qualified local Electrician.

Because no matter how hard you try, you'll never get a perfect isolation from ground. Even if there is no resistance, there will still be some kind of capacitance, allowing leakage currents to flow. And even if you could get a perfect isolation from ground, nothing lasts forever (especially in the weather).

What happens if the generator has become active potential because of an internal fault, then you are holding an appliance in your hand that is faulty & it is at neutral potential, Maybe it's a lead light so you can check the generator fuel or some other thing.

Both would be safe to touch individually but if you touch both at the same time what will happen??

If you say that's a 1 in a million chance of happening it'll never happen to me, are you willing to take the chance?

Imagine the same situation in your house 2 seperate appliances 1 with a fault making it at active potential all safe to touch until you touch another faulty appliance at the same time with a fault at neutral potential.

You said (brilliantly if I may add!):-

Imagine the same situation in your house 2 seperate appliances 1 with a fault making it at active potential all safe to touch until you touch another faulty appliance at the same time with a fault at neutral potential.

Reminded me of just how lucky a girlfriend of mine (and her family) was many years ago......

She had lived in South Africa, and similar to Australia (at least many years ago!), many devices were two wires only. Like ceramic jugs, with a bare heating element in the water, and waffel irons. UGH!!!

She had simply brought them back with her.....

The supply in SA has a polarised plug, neutral/ground on one pin and phase on the other.

Totally illegal in many countries, but in the UK where I was at the time, it could have been wired not to kill anyone....but still nowhere near correct or legal! As each plug is polarised.

She was using it, right next to her Mother's gas cooker (earth potential of course), and her father, an office manager, had wired it up!!

I told her to stand back, picked it up by the two plastic handles, and touched the metal part to the gas stove burner, causing a huge spark, a large melted bit and a loud bang, and took the whole mains off the house..........

He had wired UK phase to the frame......she was working between live chassis and grounded chassis......I had seriously saved her life......

The whole family was present, no one could speak......that must have been in 1970 when I first met her......

Even then I was MOST safety conscious.....nothing really changes.....

That unit was thrown away with the mains lead cut off at the unit.....

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Its not difficult to guess who posted this now is it? DUUHHH

I suppose I did post a difficult question to answer and still remain intelligent looking I suppose!! Sorry about that....

A full understanding of the posts you are answering to, is ALWAYS a good idea.....

Have a great day anyway, we will meet again soon I would bet!

It was me.

Australia has always used a 3 pin plug to plug into the wall socket allowing for an earth to be wired in every lead.

The only 2 pin plugs used to plug into appliances in Australia had an earth included that was the strip of spring metal that went down the broad side of the plug that made contact with the metal surrounding where the plug was inserted & gave the metal body of the appliance an earth.

The ceramic jugs were classed as a double insulated appliance as there was no metal exposed unless the lid was opened & the lid could not be opened while the plug was inserted.

So any mini stoves, waffle irons, toasters, frypans & even vacuum cleaners that had a metal body actually had earths supplied to them in this manor, so not so similar to what you are describing as in SA using the neutral as an earth connected to the body of an appliance Australia has never done that.

True. But the jugs killed a lot of people over the years, usually because it was plugged in and they dropped it, covering the local landscape with water and a live, open element!!

One would hope they have been banned by now......as even with a 3 core mains lead, they were still dangerous, no place (as you said as well) to attach a proper ground to.....to make it safer....

Though of course, as I have said many times, even such horrific jugs and other devices, would have been far safer with an RCD installed.

In SA, there was no provision for a frame ground, except much later when they started installing the UK 3 pin plug system at last..... as one side of the element was attached directly to the frame, as it was a combination Neutral/ground connection, and if you wired it wrongly, the frame went live!!

Also, if the neutral/ground wire went open circuit for some reason, you had then full phase on the frame.....horrific.....

For the uninitiated here are some pictures:-

Inside of jug showing exposed element and wiring. Only safety (?) device was that you had to unplug it to open the lid!!! If the lid got broken, mains voltages were possibly exposed.....

See here:-

Ceramic electric Jugs

Well they were used from 1020's through to early 1970's & surprising enough never heard of any deaths from using them they actually were invented by the english but they were too scared to use them lol.

Most of my family are Australians (over 70 at the last count).

I saw them being used in a cafe, while on a visit, and I remember my cousin Bob telling me that they were considered dangerous and in our Australian family, they were never used, as my Uncle (born in the UK in 1908), had forbidden them, many years before....it stuck...

I have to admit I have not seen any statistics, I simply believed Bob.....maybe not as dangerous as they "appear" to be.....no idea!

In Europe we are tiny family in comparison, with only about 18 people in all....most of the males are Electrical Engineers....some in Oz are too, but no idea how many.....

you have to decide if you are talking about a grounding rod for protecting against lightening strikes on a structure, or are you asking about the purpose of the earthing/ grounding rod or electrode in an electrical installation these are 2 different subjects.

The earthing of an electrical installation is not there for the protection from lightening strikes it is there for the protection of the consumer in the case of a fault in equipment

For example, if the power cable of your washing machine is exposed and the electrical wires come into contact with the metal case of the machine, you could be electrocuted if you touch the machine. Fortunately, when it is earthed the current goes straight into the earth wire that is bonded to the neutral at the switch board and you avoid any danger.

the grounding rod or earth electrode at an installation also works to help when there is a break in the main neutral attached to a installation if there is a fault the earth will provide a return path for the fault current back to the supply authority neutral that is also bonded to earth

Thank you! I was asking about grounding for Electrical Installation. I understand the purpose of grounding wire/ cable (to protect in case of fault) but what I don't get is driving a rod in the ground.

Even if for any reason, grounding cable breaks still using "The Earth" as return path doesn't seem plausible given it's high resistance which can't trip the breaker quick enough to save anyone in contact with faulty equipment.

Sorry, but I'm still confused. :(

You are right that the ground will not be able to trip the breaker from a ground rod alone, but neither will you if you get in the path!

Usually the ground is also interconnected to the metallic water supply system, and any building structural metal. If the soil is poor and has too high a resistance, a ground field is established using multiple grounds, connected together, usually with welded connections. If a water supply system is interconnected, a heavy jumper wire between the hot and cold piping on the water heater is required. Many water heaters use dielectric water connections to avoid electrolysis, and do not provide an adequate low resistance path between the cold and hot pipes to safely ground the system.

Yes, it can get pretty involved, without even trying!

Thank you ... very much

<...still confused...> Evidently, though reading the Wikipedia article as already suggested ought to remove it.

• The purpose of the earthing/ground conductor in an electrical supply installation is to provide a return path for the fault current that appears during a fault event that will satisfactorily operate the circuit protective device(s) to disconnect the fault from the supply without the potential on any part of the earthed/grounded equipment rising to levels that could cause harm. For example, the phase wire drops out of the contact block inside a piece of metal enclosure; because the metal is connected to the earth/ground conductor, a high current flows for a brief period as the upstream fuse blows. As the earth/ground conductor has been correctly sized and tested for integrity, the fuse disconnects the supply before the voltage on the metalwork is high enough to cause harm to anyone unfortunate enough to be in contact with it during this event.
• The purpose of the earth/ground conductor in a lightning protection installation is to create a preferred path for the lightning current to travel and in so doing effect a measure of protection against lightning strikes to the supporting structure and others in the vicinity. For example, using the Eiffel Tower as an earthed lightning rod protects surrounding structures around the Champs du Mars in Paris, lowering the chances of lightning striking them, by providing a preferential path for the discharge.

These are two different things.

<...driving a rod in the ground...> merely connects the outer extremities of metal housings for electrical equipment installations so as to provide a return path for the fault current during the brief fault event; see "TT" installation in the Wikipedia article for the reasoning. TT is not used everywhere, as the article explains, and the selection installation and verification by testing is best carried out by engaging a qualified local Electrician, who should leave a record of test of the installation at the Client's premises upon completion, and is required to do so in many nations' electrical codes.

Testing the installation at regular, prescribed, intervals in either case will establish the integrity of the earthing system conductors and identify where improvements and corrections need to be carried out. Regular testing is prescribed by many nations' standard electrical codes.

A faulty electrical installation can make one unpopular with a premises' fire insurance company; their Loss Adjusters are trained to investigate and drive the insurance claim downwards, ideally to zero.

If in doubt, engage a qualified local Electrician. These highly-trained artisans recognise substandard installations and have the skills and up-to-date trade knowledge with which to correct them as well as to install correctly from new.

I sort of get it. Thanks for detailed response.

<...when there is a break in the main neutral...>

• Were the break between the dis' board and the appliance, the appliance simply won't work, as no current can pass through it.
• Were the break somewhere on the distribution network, then consumer voltages will swing wildly as load is attached and disconnected, possibly damaging appliances to the point where they either operate the circuit overload protective device or fail open circuit in themselves.

Neither of these has anything to do with an earth electrode at the consumer end of the distribution, as the presence of a consumer earth electrode would mean it is either a TT system or an IT system, where the neutral and earth conductors are not conjoined at the consumer's premises.

Absolutely Right!

Absolutely dead right you might be!

The power company also establishes a ground reference for it's distribution.

When the power enters the premises, the neutral wire is bonded to earth ground for safety purposes, not to return energy to the source.

The farther away from the distribution panel, because of voltage drop, the greater is the difference in potential between the neutral and ground, but multiple grounds are prohibited because of the difference in potential. If you install a transformer for power Distribution, say to provide single phase from 3 phase, or from a higher voltage to a lower voltage, a ground must be established on the secondary side of the transformer, since it considered to be the source of the power.

Many sensitive electronic load installations now require an isolated ground system. It is an extra wire that feeds only the ground pin on a specialized outlet. The usual bare ground wire is connected to the enclosure or device mounting strap, and the neutral and feed wire are connected as expected,

I said in a earlier post that...

The neutral is an INTENTIONAL current carrying conductor.

The ground is an UNINTENTIONAL current carrying conductor.

The differences are critical to safe electrical distribution.

Old Joke.. My father was a conductor ----Oh really! Bus, train, tram

None of those. He was hit by lightning!

Observations regarding lightning.

Thunder is good. Thunder is impressive. But it is lightning that does the work!

Do not be upset with thunder. If you hear it, you probably were not hit!

Ever wonder how fast lightning would travel if it didn't zig-zag?

-0-

<...When the power enters the premises, the neutral wire is bonded to earth ground for safety purposes...> Ahem, ah, er...not in TT and IT earthing systems.

https://en.wikipedia.org/wiki/Earthing_system

"why does all the energy from lightning go to the Earth? Isn't it supposed to go back to source?"

In my opinion, you are speaking about Earth self-capacitance and since it is a huge capacitance no need to discharge this "to the source".See-for instance https://en.wikipedia.org/wiki/Capacitance self-capacitance.

The issue with grounding and lightning are similar. Equipment grounds are not necessarily for power-returns as in a car. They're for safety, so that if there is ever an insulation fault somewhere in the equipment, then any current leakage won't go thru the case of the equipment thru YOU to ground, but instead go thru the ground wire to ground, keeping you alive. And when lightning strikes, it's better that it goes thru a wire instead of you. However, to complete the circuit of lightning, is not like in power-systems. The strike itself is the completion of the circuit. What you missed was the charging-up of the "natural-capacitor" from static electricity. When that "natural-capacitor" reaches a threshold that exceeds the resistance of air, then it arcs across it, discharging that "natural-capacitor". And it's hard to NOT notice THAT part of the electrical circuit. Lightning can go from cloud-to-ground or cloud-to-cloud.

Thank you! Now that makes it a lot clearer. One thing more, I was watching one of Mike Holt's videos, where he explained that even though "Earth" will behave as a return path in case grounding conductor is broken, but due to high resistance, current will take all paths available including the guy touching the faulty equipment. This current will be enough to kill that person.

Which is why RCDs are recommended for all installations.

Tripping one with part of your anatomy will forever remind you to not do it again!!

But you will live!!

Read here:-

https://en.wikipedia.org/wiki/Residual-current_device

The really interesting part is that they work using only the line and the neutral, and they continuously compare that the current in one is equal and opposite to the other.

Even a tiny difference of a few milliamps, depending upon the setting and type, will trip out the mains a few milliseconds later, as it assumes that if the currents are different to each other, it has somehow found another path to earth via say a human - maybe!!

It still hurts though......

You need a Residual Exclamation Mark Device.

Two points to add.

Yes... lightning does go back to its source when it flows to the earth. A "source" is nothing more than a "source of potential difference." In the case of lightning, the source is the earth itself and the charged parts of the weather system.

On the common North American 3 wire split phase 120/240 volt single phase system, another benefit of connecting the neutral to an earth ground is that it helps to maintain system voltages to normal levels in the case of a dropped incoming utility neutral conductor.

If the neutral was not grounded at the service panel and you lost the incoming utility neutral, 120V loads on opposite rails in the panel would be connected in series across 240V.

When the neutral is tied to earth ground, because the utility neutrals are earth grounded at their poles, the connection to earth ground at the neutral keeps the middle point basically still connected, though at some unspecified impedance, to the middle of the 3 wire source.

In fact, in most customer service agreement fine print sections from the utilities, the utility mentions this fact. It is another way they get out of paying for damaged equipment when their neutral drops but the line conductors do not.