Tingling while fiddling shower taps during shower

[AndyD]

A person in a shower has a resistance a lot lower than 200K, maybe nearer 2K, I'm not sure to be honest I've never showered with my mega tester . If anyone ever mentions this again I'll deny point blank I ever advised it because I hate the things with a passion but maybe a neon screwdriver would pick up the small leakage current if you could find a way to prevent it getting saturated.

As for earthing, if your foundations are substantial and made of concrete and there's some exposed steel somewhere this often makes a good earth, it's called an Ufer earth (sometimes referred to as a CEE in the American codes). Knocking in a rod when the ground is rocky is just pot luck. You should certainly go with the thicker rods, I remember hammering one in for hours one time, we attached the fourth or fifth 2.3m rod and shortly afterwards the far end of the rod surfaced through the driveway tarmac about 6 meters away from where we started. It can be a demoralising exercise.

[Sparks]

No fault with the answers you already have. I am also inclined to suspect high loop impedance. The only thing is that you do not mention the tingle when using the stove or light switches or touching light fittings so I would normally be leaning toward a hairline crack in the element, however, as the neightbours are experiencing the same problem, it rules that out. Having no voltage reading between N & E means they are at the same potential, no elevated voltage not no voltage and as Andy said, it is not the voltage which will kill you. As for the ELCB, I doubt your geyser circuit is connected to it. I suggest you get the local authorities out and leave it to them. You can always motivate them by calling to ask where or by whom do you submit a claim for electrocution. That will light a fire under them. Keep in mind also that the neutral at the geyser is the same as the one at the lights and stove so when either are being used the geyser neutral should have a potential difference of 220V to earth.

[AndyD]

Keep in mind also that the neutral at the geyser is the same as the one at the lights and stove so when either are being used the geyser neutral should have a potential difference of 220V to earth.

I might be misunderstanding this part but usually the neutral should have zero potential to earth.

I'm worried if your on a PME system the council is just going to tell you to get an electrician to improve your Ir (rod imdedance) which they will see as your problem, not theirs.

I'm trying out a new drawing package so here's another test I've devised for you. Have fun

[Justloadit]

The only thing is that you do not mention the tingle when using the stove or light switches or touching light fittings so I would normally be leaning toward a hairline crack in the element, however, as the neightbours are experiencing the same problem, it rules that out. Having no voltage reading between N & E means they are at the same potential, no elevated voltage not no voltage and as Andy said, it is not the voltage which will kill you. As for the ELCB, I doubt your geyser circuit is connected to it.

We have no tingling feeling on any other appliance, and this being a small house, all circuits go through the Earth Leakage Switch. Even when we wash dishes we do not get any tingling feeling, but then again it is a metal basin. Baths or basins do not behave as the shower either, which makes it even more puzzling.

Keep in mind also that the neutral at the geyser is the same as the one at the lights and stove so when either are being used the geyser neutral should have a potential difference of 220V to earth.

Not sure what you mean by this statement, if you measure the voltage between live and neutral or earth, it does show 230V.

[Justloadit]

OK, I managed to get a voltage measurement. Its a mere 6 Volts 50hZ AC, but it sure does frighten you when you do not know what the heck it is. I can not measure the current, because the cheap multimeter I currently have in my possession does not measure AC current.

It reminds me of a redesign which I did some time ago for somebody, but never came to fruition because the client ran out of money, and I never got paid.

But if you check out this video, Farm Freund, you will get a pretty good idea how good the concept is. It was originally patented by RAU university. It immobilizes farm animals allowing vets to do their thing. The voltage is variable between 1 and 12V, at a frequency lower than the mains frequency, but is very effective, and when I tested it, I recall having the same tingling feeling.

[AndyD]

The thing with induced or capacitively coupled voltages is that they can be deceptive. Depending on the input resistance of your test meter you'll get different voltage readings. The whack you get from it is more down to the energy it can deliver, as previously stated this is more about the Amps or Joules.

If you can see the voltage on your tester then at least you can get a handle on what is causing the fault. What 2 points did you get your 6VAC measurement between? I would first try to narrow it down to which circuit is causing the reading, isolate all circuits at the DB, check that the 6 Volt reading has gone then reset each circuit one by one to establish which is the guilty one.

[Justloadit]

Hi Andy,

I placed a copper wire, not the best connection as it has no real point to bolt too, between the taps and the drain hole, then let the shower water run, measured between the taps, and the shower floor which are earth type of tiles, which was now damp. At this time the only circuit that I had isolated was the geyser. Will do a further test with all the other circuit breakers.

I was hoping that the wire would have eliminated the tingling feeling but it seems not to have made any difference.

[Justloadit]

OK I have now managed to get a measurement with out the shower flowing. By placing the meter between the taps, and a tile joint which was damp, I managed to measure the 6V. So it seems there is this residual voltage flowing in between the copper pipes, which in the shower come from the ceiling and chased into the wall and the ground cement.

I switched off all the CBs, and even the EL isolation switch, which disconnects both live and neutral, and there still was a reading. Off course I could not remove the earth wire, and bear in mind at the meter box, the earth is connected to the neutral.

SO confirmation that there is no electrical fault in the house, and that this must be influenced from an outside source.

Now if there was a general ESKOM power failure, it would yield an interesting result, but there have been none for a while, so I have not been able to do a measurement.

[wynn]

As an electrical ignoramus I would also check appliances such as washing machines, dish washers, ice machines and fridges with water connected for ice/cold water dispensing. one of them could be causing a crossover.

Oh and change your geyser element and thermostat.

[AndyD]

Is the meter box on your premises?

As a final test you could isolate the entire DB at the main breaker and disconnect the main incoming earth from the earth bar. Obviously don't reset the supply without reconnecting the main earth again. If the 6 volts test result disappears then it pretty much proves that your incoming earth is at an elevated voltage to actual earth.

If this is the case then by all means contact the council but my advice about adding an additional decent length rod close to the DB still stands as a good option. Additional earth bonding to the house foundation steelwork if possible would be even better.

Out of interest, did you physically check all electrical points in the vicinity of the shower for signs of damp?