I live in Egypt where the neutral wire is grounded. The ground wire is not separated from the neutral wire. A wall outlet has two holes only (live and neutral), The third whole (ground) does not exist.

According to this question, I can NOT use neutral wire as a ground:

Why don't we use neutral wire for to ground devices and earth wire for closing the circuit?

So, How can I protect myself from the weak electrical shocks that happens when I touch the metal case of an electric device? Such as: The metal case of a personal computer or a washing machine.

I have one more question, What makes the shock too weak? I accidentally touched the live wire before and it was horrible.

If the live wire touches the metal case and then I touched the metal case, What makes the shock weaker? And If the live wire does not touche the metal case, What is the supply of the metal case? What causes the weak shock?

Thank you very much,

  • 1
    \$\begingroup\$ Is the earth wire connected to anything or just left unconnected? \$\endgroup\$
    – Transistor
    Commented Jul 28, 2016 at 22:50
  • \$\begingroup\$ You write: "I live in Egypt where the neutral wire is grounded." and then you go on to write: "According to this question, I can NOT use neutral wire as a ground:", which confuses me since, if your neutral wire is grounded, and you've only got two terminal outlets, how is it possible to unground it? \$\endgroup\$
    – EM Fields
    Commented Jul 28, 2016 at 22:53
  • 3
    \$\begingroup\$ @EMFields I think the OP is referring to a system where the neutral is connected to ground at the panel, but shouldn't be used for protective earth purposes. (Since there's so much potential (sorry for the pun) for the outlet to be wired backwards for example.) \$\endgroup\$
    – John D
    Commented Jul 28, 2016 at 23:20
  • 2
    \$\begingroup\$ +1 For actually writing your country instead of handwaving it in some misguided pretense of trying to make the question "generic". It annoys me so much that I had to write a long rant on my profile page. \$\endgroup\$
    – pipe
    Commented Jul 29, 2016 at 4:06
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    \$\begingroup\$ Some places in the UK are similar, we call this TN-C-S (see this PDF for info). Individual outlets still have their own earth. \$\endgroup\$
    – David
    Commented Jul 29, 2016 at 6:11

6 Answers 6


Usually the tingle you feel when touching an ungrounded case of a device is due to a capacitor (called a Y-cap, for EMI reduction) from the line to the case. This is a special safety-rated capacitor which will not allow a dangerous amount of current to leak onto the case. Nevertheless, the case is intended to be grounded so that you don't feel the tingle. You could connect the case to a grounding rod or maybe a cold water pipe.

For safety in the case of a live wire contacting an ungrounded case you could replace your outlets with ground fault interrupter type outlets. Then if you come between line (hot case) and some external ground you would be protected.


Using a very nice description linked in a comment from user @David:

TN-C-S system mains wiring

(Image source: The IEE, Wiring Matters magazine, issue 16, Autumn 2005)

Neutral and earth are connected together, but in main cabinet side. The Neutral and Earth may be split from PEN just once. Then you have got three wires, so you need to change the entire installation.

In case the PEN wire breaks, there is still danger, therefore an earthing rod is needed. In the image, an "Additional Source Electrode" is shown. For further safety, a GFCI can be installed at the point where the circuit is split with dots in the image.

What you may not do, is the link you added. You may not connect neutral to earth in the connecting plug of an appliance. Also the used terminology is incorrect:

I can NOT use neutral wire as a ground.

Rather, the neutral is split from earth (therefore you already have the earth) and not vice-versa.

  • 2
    \$\begingroup\$ Using an earthing rod may be difficult in Egypt. In a dry area, the earth resistance will be high and the current caused by a short between live and earthing rod may be to low to break the fuse. \$\endgroup\$
    – Uwe
    Commented Jul 29, 2016 at 7:53

Egypt's electrical wiring regulations conform with IEC standards.
It is likely that what you are describing is what is typically done and not what is required to be done. ie it is likely that the installation is technically illegal. This does not mean that anyone in authority cares enough to do anything about it.

This document International electrical standards & regulations shows wiring standards applicable worldwide. On page 2 it shows Egypt as using IEC standards. Sockets are meant to be to the IEC German standard - page 16 - two pin no polarised with side wiping earth contact.

They say

  • GENERAL CIRCUITS These circuits supply both lighting points and socket outlets. The rating of the protective device is usually 16 A. There is no limitation of the number of outlets on a circuit. This limit is calculated according to expected/ probable use of the circuit. Socket outlets are generally of the 2P+E type “German". These plugs are non polarized. All German socket outlets are earthed. In general, the protective conductor is distributed throughout all circuits. For class II devices < 2.5 A, the Euro-plug is used. The wire cross-section of the fixed installed cables is normally 1.5mm² (protected by a 16 A Circuit Breaker).


  • EARTHING Earthing is local, usually through a foundation earthing arrangement. All metallic services shall be bonded (gas and water pipe, heating, waste systems, etc.) with a 10 mm2. In bathrooms the local equipotential bonding could have a cross sectional area of 4 mm2. Neutral is re-earthed in the control panel. A protective conductor is distributed to all socket outlets.


IEC membership

Electrical outlets

World electricity standards


As JohnD said - a GFI / ELCB (ground fault interupter / earth leak circuit breaker may disconnect the circuit when you feel shocks (depending on how much leakage is present, but with the system you describe this could be a major inconvenience.

I'm not suggesting that the following is sensible or practical or even safe - but it is a system that SHOULD work, but which is non standard and may violate local regulatory standards:

Provide a local ground with waterpipe or similar.

  • This MAY exist already and MAY already be connected to neutral at your switch board. @Alephzero noted that connection to a "waterpipe" at random locations in a residence may be both dangerous - and also illegal in some countries. I agree that this is unwise. What I intended to convey is that the point where a main metal water-pipe for a home enters the ground is usually a good point for either an earth rod and/or for connection to the metal water-pipe. In some regulatory systems it is required that a suitably designed ground system be established AND that this is bonded to the water pipe at the point of entry to the ground (soil). This ensures that the ground-connection is a good one (by design) and that the formal and water-pipe ground connections do not develop a potential difference during a major fault, due to one or other having a lower resistance to true ground.

Provide 3 pin appliance sockets with ground connection.

Extend ground as above to socket ground.

Fit appliance with 3 pin plug and cord and connect body to ground wire.

Safe?: Probably but not certainly. IF your local system happens to provide high voltage to the body of an appliance, connecting ground may or may not be a 'good idea'.


Regulations and practices in NZ as an example:

Here is the related NZ code of practice for earthing. It is essentially certain that Egypt has equivalent standards documents available.


NZ electrical safety regulations and as DF here


Wikipedia Earthing Systems

Here is a worthwhile 76 page pdf from AVO on ground resistance testing
Introductory page PDF A practical guide to Earth Resistance Testing

  • 3
    \$\begingroup\$ "Provide a local ground with waterpipe or similar." That is bad advice. One day, an electrical fault will connect the live side of the mains supply to your water pipe, which for some reason was never actually connected to earth even though you thought it was (Teflon plumbing tape used for sealing joints is a pretty good electrical insulator). If somebody then touches a metal tap with wet hands, they might not survive the experience. Using water or gas pipes as an electrical earth is illegal in the UK. \$\endgroup\$
    – alephzero
    Commented Jul 29, 2016 at 4:38
  • 1
    \$\begingroup\$ @alephzero (1) Note that I specifically said: " I'm not suggesting that the following is sensible or practical or even safe ... is non standard and may violate local regulatory standards...". The main point was to show how much effort is involved in providing a ground system & 3 pin socket - ground, connection, new socket, new cable, connection in appliance. ... \$\endgroup\$
    – Russell McMahon
    Commented Jul 29, 2016 at 10:09
  • \$\begingroup\$ @alephzero ... (2) I agree with you that the "ground" in such a system MUST be GROUND. When I said 'local ground' I meant one which was connected to true ground. I apparently should have made that clearer. As this was a concept (unsafe/illegal/impractical ... works) I did not go into detail about how the ground should be made. Your concern was worth noting ! :-) \$\endgroup\$
    – Russell McMahon
    Commented Jul 29, 2016 at 10:10

So, How can I protect myself from the weak electrical shocks that happens when I touch the metal case of an electric device? Such as: The metal case of a personal computer or a washing machine.

Start with an isolation transformer so that the "new" neutral and live are isolated. Connect the new neutral to earth at one point (distribution point or "new" fuse board) and wire this point also to a very solid gounding rod. Next use RCDs (GFCI in the US) for your power circuits.

Yes it's complicated but you asked!


Thank you for this thread. I too live in a part of the world where the "tingling" is almost as common as the nonexistent grounding/earth path available at the outlets.
When asked about how the existing circuit is grounded, adding a ground path, potential danger of there not being an independent ground circuit, the most common response is a sideways tilt of the head combined with a furrowing of the brow, mild squint of the eyes and a far-away look displaying the question; "hmmm, what is this guy talking about?" :-) Rewiring the home was not an option. So I ended up adding an isolation transformer to the 230V service where I have sensitive electronics and devices that require direct, constant contact (both in the same area) such as guitar/amplifier, laptop computer, etc. So far, for me, this has worked out well. I sunk a dedicated ground rod into the ground tied to the ground leg of the secondary side of the iso.
No more tingling, and my outlet tester now shows that all three components of the wall power are doing what they are supposed to.
I know this idea isn't feasible for everyone. But I wanted to share that it did work for me.
Good luck


The tingling you feel when you touch an appliance is due to (current caused by) a difference in potential between the appliance, and something else which you are touching. The other thing you are touching which has a different potential could be another appliance, the floor, a pipe, etc.

One step that you can take, which will (hopefully) protect you from dangerous shocks is to install GFCI or RCD between the mains power, and the appliance which is giving you a shock. These devices will disconnect power if the current into your appliance is sufficiently different from the current returning from your appliance. Although such devices will protect you from dangerous shocks, they may not protect you from milder shocks, such as your "tingling".

To eliminate the tingling, the potential of your appliance must be brought to the same potential as the other item which your are touching, and which is (until now) at a different potential. Why isn't it at the same potential already? Although the mains power is (typically) grounded in one leg at the transformer, and/or at the point of entry to your building, through a grounding rod, there is resistance between the grounding rod and various objects that you would like to be grounded. This is especially true if the grounding rod is driven into dry sandy or gravelly soil.

Creating a ground ring (or ring ground) can help keep different parts of the ground at the same potential. To create a ring ground, a bare wire is buried around the outside of the building, and this ring is bonded to the ground rod at the entry point of the mains supply WHICH SHOULD BE BONDED TO NEUTRAL. This ring should also be bonded to any metal pipes, conduits, or other metal objects that are permanent fixtures of the building. If there are metal pipes in the house that are separated by plastic, or in some cases a hot water heater, a wire should be bonded to the different sections of pipe so that there is a conductive path between all metal parts in the building. If the building contains reinforced concrete (for example in floors) then ideally, the grounding wires should be bonded to the rebar inside the concrete.

Now, here comes the tricky part. Your appliances are not permanent parts of your building. A laptop certainly isn't. How can these appliances be brought to the same potential as the grounding system? One option is to rewire the building to have grounded outlets. If this is not feasible, another option, which may be a code violation, is to connect a grounding wire, say from an exposed metal part of your washing machine, to the metal pipe, which in the previous instructions, we have bonded to the rest of the grounding system. If everything works as planned, the potential of your washing machine will now be at the same potential as the floor. So, touching the washing machine while touching the floor, or a pipe, should not give you a tingling sensation or shock.

If there is no fault in the washing machine, the leakage current should be small enough that connecting an exposed metal part of the washing machine to ground will not trip the GFCI/RCD. You will have both protected yourself from severe and dangerous shock (using the GFCI/RCD) and from mild shock, by bringing the chassis of the washing machine to the same potential as the floor. However, if there is a fault in the washing machine, the GFCI/RCD will trip. IF THAT HAPPENS, DON'T DISCONNECT the GFCI/RCD. The GFCI/RCD protects your life and is more important than eliminating the annoying tingling sensation. Rainfall may drastically change the conductivity of the soil, and what was once a minor fault current from your appliance to ground might become dangerous. If your appliance has a fault sufficient to trip a GFCI/RCD when its chassis is fully grounded, then you need to investigate and repair that fault. Again, don't disconnect the GFCI/RCD.

You can apply the same trick to your computer that was applied to your washing machine, although it is certainly more inconvenient, and is certainly not a code approved way to protect yourself. That is, using a GFCI/RCD along the power path to your computer, and after you have brought all the conductive parts of your building to the same ground potential, you can run a wire from the chassis of your computer to a grounded pipe. Again, this should bring the chassis of your computer to the same potential as anything else you might be touching, and hence eliminate any annoying mild shocks. Again, this is probably not a code approved way to wire things. The "best" solution, would be to rewire the electrical system to include ground wires, and use plugs with ground prongs on them, AND use GFCI/RCD outlets, or GFCI/RCD circuit breakers at the panel, or stand alone GFCI/RCD modules between the outlets and my appliances.


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