Single-Phase House Wiring: Earth/Ground Conductor

You are right. The earth wire is never in the perview of the Electricity Supply/ Distribution Company.

You have to stand on your own ground .

Just remember, I have heard, and may be true, a lot of shortcuts are done by using the waterpipeline as the earth electrode. Ensure it is not done.

get an earthpit dug in your compound, and put the earthing electrode over there. And then if you like as in my house, we have run the 3 core cables (Phase, neutral and earth) all around.

Also put and ELCB in the circuit for safety of the persons. Tell the electrician and he will put it.

You'll get plenty of answers to this request. For my computers, I have run dedicated earth wires from a ground rod driven into the ground to the outlets my computers use. I had to change the outlets from two plug to three plug.

For a whole house, hire an electrician. If your house has old wiring, it will have an obsolete breaker box, probably. All the wires and boxes will need to be replaced, all the circuits will need to be re-engineered. GFI is code in kitchens and bathrooms, probably utility rooms too.

While rewiring, consider running phone, cable, networking, etc. The electrician can recommend what you will need.

change your supply board to include an RCD on the main incoming supply, all the fuses change to MCB's run an additional earth cables to ALL outlets (sockets and light fittings) and get a 2 meter copper earth rod and bury it in the ground, (if sandy ground even longer and maybe several) but DO NOT attempt it yourself and ask the electrical contract what he would do, look for these answers coming back from him, then you know he knows his stuff, you can also check the IEE 16th Edition Elect Regs - covers its all.

You can run a grounding wire separate from the devices and fixtures you are connecting to. Just make sure they return to the "single point of ground" at the main service. All other grounding rules apply.

Most home owners find grounding all devices and fixture too expensive to do. I don't know what country you are in, but in the USA you are allowed to use Ground Fault Equipment to simulate a grounding point on your receptacles. I refer you to NEC 406.3 (D).

Also I will recommend a small UPS for computer equipment inside a residence like this. It creates its own isolated ground, provides surge protection and prevents a hard crash of the computer in the event of an outage.

I'm not sure Ground Fault Equipment will simulate a grounding point. It will disconnect the power from the circuit if it detects ground fault.

A UPS might serve as an isolation transformer.

I ran dedicated ground wires because I read that the computer memory needed a ground reference. Also it protects my equipment from lightning strikes better than just the white wire.

EARTHING SYSTEMS These have been designated in the IEE Regulations using the letters: T, N, C and S. These letters stand for:[p/] T - terre (French for earth) and meaning a direct connection to earth. N - neutral C - combined S - separate. When these letters are grouped, they form the classification of a type of system. The first letter denotes how the supply source is earthed. The second denotes how the metalwork of an installation is earthed. The third and fourth indicate the functions of neutral and protective conductors. TT SYSTEM A TT system has a direct connection to the supply source to earth and a direct connection of the installation metalwork to earth. An example is an overhead line supply with earth electrodes, and the mass of earth as a return path as shown below. Note that only single-phase systems have been shown for simplicity.[p/] TN-S SYSTEM A TN-S system has the supply source directly connected to earth, the installation metalwork connected to the neutral of the supply source via the lead sheath of the supply cable, and the neutral and protective conductors throughout the whole system performing separate functions. The resistance around the loop P-B-N-E should be no more than 0.8 ohms. TN-C-S SYSTEM A TN-C-S system is as the TN-S but the supply cable sheath is also the neutral, i.e. it forms a combined earth/neutral conductor known as a PEN (protective earthed neutral) conductor. The installation earth and neutral are separate conductors. This system is also known as PME (protective multiple earthing). The resistance around the P-B-N-N loop should be less than 0.35 ohms. SUMMARY OF EARTHING SYSTEMS The TT method is used mostly in country areas with overhead transmission lines. In contrast to the TN-S system there is no metallic path from the consumer's terminals back to the sub-station transformer secondary windings. Because the earth path may be of high resistance, a residual current circuit-breaker (R.C.C.B.) is often fitted so that if a fault current flows in the earth path then a trip disconnects the phase supply. For protection against indirect contact in domestic premises, every socket outlet requires an RCCB with a maximum rated current of 30mA. The TN-S system of wiring uses the incoming cable sheath as the earth return path and the phase and neutral have separate conductors. The neutral is then connected to earth back at the transformer sub-station. Remember in TN-S, the T stands for earth (terre), N for neutral and S denotes that the protective (earth) and neutral conductors are separate. The TN-C-S system has only two conductors in the incoming cable, one phase and the other neutral. The earth is linked to the neutral at the consumer unit. The neutral therefore is really a combined earth/neutral conductor hence the name PME. In order to avoid the risk of serious electric shock, it is important to provide a path for earth leakage currents to operate the circuit protection, and to endeavour to maintain all metalwork at the same potential. This is achieved by bonding together all metalwork of electrical and non-electrical systems to earth. The path for leakage currents would then be via the earth itself in TT systems or by a metallic return path in TN-S or TN-C-S systems. NOTES Older houses in towns use TNS (solid) i.e. separate earth say cable sheath. Around Towns new houses use (PME) TNCS i.e. neutral and earth shared. Single House in country with own transformer uses TT i.e. own buried earth electrode. Petrol stations, Swimming pools, Changing rooms etc. are not allowed to be PME.

http://www.arca53.dsl.pipex.com/index_files/elect4.htm follow this link

The way it was taught to me is "White meets green at the meter, not before"

There is an article on this topic in Wikipedia. Look at TT earthing for reference.

As indicated above, it is desirable to install a whole-house RCD on the incoming wires. In the UK, 100mA imbalance is a typical trip point on TT systems, though local electrical codes must always be followed. If in doubt, consult a qualified electrician locally.

House current in the US is 110/220. There are two hot conductors of 110 volts each,and a white neutral fed from the pole. Most appliances use 110, one hot and a white. Stoves and dryers use 220, two hots, no white. If the stove or dryer needs 110 for a motor or clock, the white wire is used. Green is for earth ground, the safety, it's clamped to a ground rod.

How is it done in The UK?

Mike......... In the UK, 240 volts, single phase. 3 conductors, 1 live @ 240v potential, 1 neutral and one earth. If you look at my previous answer, long as it might be, that is the type of systems we use in the UK. We conform to the 17th Editions elect regulations which conform to BS 7576. All domestic & office appliances are 240 volt including lighting, only industrial tools are 110 volt & some safety equipment (sometimes lower than 110 Volt). A house can be supplied either overhead from suspended cables or via buried cable. Also we have different sockets or outlets, whereas in the UK each socket has its own isolator switch, in the States the outlets do not, you just pull them out or push on and you have power. Hope I've helped

Thank You all for your replies!

I live in India and we've 240v/50hz single phase supply (similiar to UK?).

Once again, thanks for your answers!

in south africa we use 380V transformers (secondary side) connected in Y. your Y point is always earthed. any of the 3 phases to earth will give you 220V. i think thats why you only have 2 wires to your house, one live wire and one neutral(earthed at your transformer). it is only after your earth leakage protection (ELCB) that you seperate your neutral and earth. your neutral wire must be earthed before entering your ELCB and after that you should seperate them.that is when you start using a 3 wire system.all your equipment must be earthed by using an earth spike and connecting it to your water pipes and all steel structures around your house. your earth leakage protection is very important as it will cause a power trip for earth faults either caused by faulty equipment or electrocution