Electric shock between electric shower hose and bath taps

[flydigital]

I have an electric shower unit above a bath. While it is on, if I touch both the shower hose and the brass taps of the bath I get a shock.

Also if the hose is in the water filling the bath (there is no boiler at the moment) you get I very mild shock from the water.

Doesn't seem very safe really! I'm planning to get an electrician in on Tuesday but would be interested to hear anything on what is causing this.

Thanks for your help.

 

[Lectrician]

The hoses are usually earthed by the showers by a small metal slither of metal at the threaded outlet.

Could be a few things:

Your bath taps are earthed, but your shower is not. Shower has a faulty element (low insulation resistance, not neccessarily direct short), giving a rise of volts on the hose due to lack of earth.


or


You have some circulating currents in your earth conductors due to either odd effects of PME, or a fault somewhere in the house which is not causing operation of protective device. With a lack of supplememntary bonding, even if the items are correctly earthed, a potential can exist between the earthed items due to current flow creating voltage differentials. This is 'percieved shock'.

I would suggest it is likely the first, as you say it only happens with the shower on.

I would isolate the shower, and not use until this is sorted! Seriously!

A lack of earthing to a circuit or to an entire installation is FAR TOO COMMON in my experience.

 

[Steve]

Update your bonding. You can do this yourself

 

[flydigital]

Your bath taps are earthed, but your shower is not. Shower has a faulty element (low insulation resistance, not neccessarily direct short), giving a rise of volts on the hose due to lack of earth.

The pipe to the shower is plastic. The pipe to the bath is copper. Does this cause the voltage potential - ie the flow now goes into me rather than the pipe?

 

[Lectrician]

Your bath taps are earthed, but your shower is not. Shower has a faulty element (low insulation resistance, not neccessarily direct short), giving a rise of volts on the hose due to lack of earth.

The pipe to the shower is plastic. The pipe to the bath is copper. Does this cause the voltage potential - ie the flow now goes into me rather than the pipe?

No.

You bath taps are fed by copper, and well earthed (I guess....due to shock).

The shower pipe makes little odds, as the shower is earthed internally by the earth in the cable......or should be!

The hose of the shower will be connected to the earth of the shower by the small metal tab on the hose union on shower.

No earth to shower could be due to no earth to entire house, no earth to shower CU, broken earth in cable, earth fallen out of terminal etc etc

 

[flydigital]

It turns out there was no earth, as you say, to the entire house. I reconnected the earth and the problem has gone.

Using a mutimeter it registered 47v between the tap and the shower. It was actually the water runing through the pipe and making direct contact with the bath water, not the hose itself.

The 46v was there even with the double pole switch off, so as you say it was an earth issue not the unit?

But was the existence of the 46v potential a sign of another fault somewhere?

 

[RF Lighting]

The 46V you measured is an induced voltage.

This is normal if the earth is not actually connected to earth, ad often rises to 120V

Connecting the earth wire to earth allows this very small bit of electricity to flow to earth, so no voltage is present on the earth wire.

 

[Softus]

It turns out there was no earth, as you say, to the entire house. I reconnected the earth and the problem has gone.

Now that you've put it right, presumably you get your thrills by dangling your naked genitals over some red hot coals?

 

[gas4you]

It turns out there was no earth, as you say, to the entire house. I reconnected the earth and the problem has gone.

Now that you've put it right, presumably you get your thrills by dangling your naked genitals over some red hot coals?