Earthing

[esperowl]

Hi, what is the proper name for the technique when a heavy duty earth cable is connected to earthing spikes placed outside of your house?
So that I can research the correct term, its not simply called 'earthing' is it?

Also, do I connect the other end of the earth cable to my mains box? Has anyone tried this and found it beneficial?
Many Thanks.

[Barry]

Hi, what is the proper name for the technique when a heavy duty earth cable is connected to earthing spikes placed outside of your house?
So that I can research the correct term, its not simply called 'earthing' is it?

Also, do I connect the other end of the earth cable to my mains box? Has anyone tried this and found it beneficial?
Many Thanks.

Try "earth rod", "earthing rod" or "grounding rod".

Before you do anything though, it would be wise for you to contact you local electricity provider to find out what the earthing provisions are already in place with the supply into your house. With some earthing arrangements, adding additional earth rods can be a potentially dangerous thing to do!

[The Grand Wazoo]

Hi Chang,
Whatever you discover and then decide to do, can I offer some friendly advice please?
Since your question reveals the depth of your knowledge on the subject of mains, please, please don't do it yourself. You are quite obviously not equipped to do this, so recruit someone who does.

[esperowl]

Cheers guys and thanks for your concern. There's no way I would do this by myself. I have to double check with forum members before even attempting to connect a transport to a DAC - see my last thread :rolleyes:).

[The Grand Wazoo]

There's no way I would do this by myself.
That's good to hear!

[PaulStewart]

Hi Chang,
Whatever you discover and then decide to do, can I offer some friendly advice please?
Since your question reveals the depth of your knowledge on the subject of mains, please, please don't do it yourself. You are quite obviously not equipped to do this, so recruit someone who does.


+1 to thatget a qualified electrician to do the work. The correct term for a separate earth is a "Technical Earth", the best way to instal one is to either use a series of rods driven at least one metre into the earth or bury a metal sheet about 1.5 meters square about a metre down. The other way, that I have used myself is and old water 2m down. you need the shortest, thickest earth lead you can use. This will dramatically reduce noise levels. When i put one of these under a manufacturers HiFi Showroom in the 70s we measured a 4.5 volt difference between this true earth and the board earth at the fuse box, so a tremendous potential for noise was removed.

But I repeat the suggestion that you get a sparks to do the work

[esperowl]

The other way, that I have used myself is and old water 2m down.

Again please?

So the potential benefit is that you get a true voltage and this reduces noise levels?
Is there any point in a technical earth if I'm already using an AC regenerator?

[PaulStewart]

Sorry mate I'm picture editing and typing between pics that should have read an old water tank buried 2 metres down

The advantage is you have no voltage offset on the earth, it's a true earth and will prevent a lot of spurious nasties. With a regenerator you are just recreating a clean wave form, in my opinion a true earth is always best as are clean spurs and balanced mains supply, then a regenerator/conditioner and proper mains leads for the best mains you can get. After that you just have to sort out suppressors on the fridge/extractor fans and other motors and the worlds your lobster :lol:

[Barry]

The following might be of interest:

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

http://wiki.diyfaq.org.uk/index.php?title=Earthing_Types

and

http://www.acoustica.org.uk/t/earth.html

The latter explains why, if your mains supplier uses the TN-C-S earthing arrangement (also known as PME), adding extra earthing rods can be potentially dangerous.

Before you do anything, consult your local mains electricity supplier, and if you decide to have additional earthing rods installed, have the work done and tested by a qualified electrician.

[lurcher]

When i put one of these under a manufacturers HiFi Showroom in the 70s we measured a 4.5 volt difference between this true earth and the board earth at the fuse box, so a tremendous potential for noise was removed.

But, just for balance, you may also have added noise to the system. The board earth is just the supply company "neutral" bonded to the house protective earth. So now if all your kit is referenced to the new earth, it can "see" noise and DC on the neutral, when before everything moved up and down together.

Also if you connected the new earth to the protective earth, that 4.5v would create a earth fault current, it would possibly be large, potentially setting fire to your house large under certain conditions.

And if you keep the two earth’s separate, your protective earth in the house could under the same fault conditions become 100's of volts different from your new earth. You will find that if you come into contact with both earth’s at the same time. If as is normal everything is bonded to the normal earth, you will never notice, as everything moves up together.

Not saying its not a good thing, just pointing out a couple of the potential problems.

[Naughty Nigel]

I don't want to offend anyone but it does worry me that people discuss earthling arrangements on open forum when they clearly don't have a clue how these systems work! There was a similar discussion a few weeks ago when someone advocated DISCONECTING the earth connection to an amplifier because they thought it sounded better that way. :rolleyes:

As Nick says, the 'Board' earth is simply the supply company neutral connection, which formed by the protective metal sheath on your incoming supply. This will be connected to ground (via a large copper plate) at the local transformer, and must be connected to your household earth circuit. Crucially, the Board earth must (by law) be connected to your incoming water supply pipe, unless it is plastic, in which case it must be bonded to the copper pipework immediately downstream of the water Stop Cock using copper cable of 10 millimetres cross section. Similarly, the Board earth must also be bonded to any incoming gas pipe if fitted, again using 10 mm2 copper cable. This is known as 'equipotential earth bonding'.

(The above describes the usual underground supply arrangements here in the UK, which rarely include any form of earthling rod. Where an overhead electricity supply is involved the electricity company should also provide an earthling rod.)

Similar requirements apply where electric sockets are fitted within reach (1.5 metres I think) of kitchen sinks and so forth. In this case equipotential earth bonding must be fitted between the socket outlet (earth connection) and ALL water pipes connected to the sink, or to the sink/taps themselves if the pipes are plastic. (Six millimetre copper cable must be used.) Similarly, equipotential earth bonding must be fitted between each pair of hot and cold water pipes directly beneath each sink, bath and so forth.

The object of the Protective Multiple Earth system is to safely conduct away any fault current so that a fuse or circuit breaker trips before any harm is done to people or property. This system is designed so dangerous 'differential' voltages do not develop between adjacent metalwork (i.e. hot and cold taps) and so forth.

However, the PME system was not always effective, so 'equipotential earth bonding' was introduced to provide additional safeguards against dangerous voltages between objects which could be touched at the same time. So, if for example an electric kettle develops a leak to earth, the equipotential earth system will ensure that the kettle and cold water tap remain at the same potential. Even if the main earth circuit fails the kettle and cold tap will still be at the same potential, even though they may both be live, as that is much safer than having one at earth potential and the other at 240 volts.


I have not, so far discussed earth leakage protection, which provides an additional safeguard against electrocution. Present day RCD systems simultaneously measure the current flowing into a circuit or building through the Live conductor and out through the Neutral conductor. Any imbalance indicates a leak to earth somewhere, which trips the circuit breaker if a certain threshold (usually 30 milliamps) is exceeded. (Older systems measured current flowing to earth, but these were unreliable and were prone to false triggering during thunderstorms.)

Most electrocutions involve leaks to earth so an RCD (Residual Current Device) is strongly recommended, and will not affect the sound of your HiFi!

Nigel.

[Ali Tait]

Good advice. I run my system via a balanced transformer, both legs protected by a two pole RCBO.

[PaulStewart]

Nick,

In most cases when I've used external earth's it has improved noise performance. Back in the late 60s the trick was taught to me by my uncle. He was a former Chief electrical engineer on tankers and a construction industry sparks, so he knew a thing or two about electrical safety he also encouraged me to get my ticket and work as a sparks. He was a very early HiFi enthusiast and ham radio operator too. I used to help him out when I was a teenager and needed money :lol: I have to say that these days with RCDs etc. it's pretty easy to keep these things safe, but I would always reiterate GET IT DONE OR CHECKED OUT BY A PROFESSIONAL BEFORE YOU SWITCH IT ON.

[brucew268]

Based on anecdotes I've read, not every sparks really has any idea what it takes to implement an effective earth system, and often the end result has worse earthing effectiveness rather than better... even if you don't have a PME system that it needs to 'play well' with. So may be a good idea to read a little about various earthing systems and how soil conditions, special materials, and multiple rod arrays are sometimes implemented and then ask the sparky some questions to see if they are conversant with various approaches and when one is indicated or contra indicated. If you get a blank stare or non-substantive answer, I'd be looking for another electrician. But that's just me, not wanting to throw good money after bad.

[Naughty Nigel]

Presumably the Americans have fewer earth related problems than we do in Europe as their supply voltage is much lower, (117 volts nominal), and I believe is centre-tapped to earth? Hence their maximum phase to earth voltage is less than 60 volts, compared with 240 volts in the UK, although currents are more than doubled.

Nigel.