Stray voltage from dishwasher case to central heating pipes

[Dazzy50]

Hi,
Was hoping you could help. Recently had a small shock from touching the inside metal case of dishwasher. Immediately isolated the electrics and checked behind the wall socket face plate. That was fine. I checked the plug and found that there was poor ground contact so have re- screwed in contacts securely.

To check if there was any stray voltage I checked using my multimeter from the case of the dishwasher to a nearby central heating pipe which I know is earthed.

There is a very small voltage reading of ~270 millivolts. Is this a genuine reading and more importantly is it a safety problem?

Kind regards

Daz

 

[Iggifer]

Well, first question is, was the washing machine plugged in and turned on when you got your shock? Sounds like it was. If so, silly thing to do.

270mV is NOTHING. Almost all, if not all, appliances leak a small amount of current to earth, and if the casing of the machine is earthed, it'll show that small amount of current there on it's way down to earth.

 

[Taylortwocities]

I'm guessing you don't get a shock any more then?

Digital voltmeters will pick up all sorts of stray, induced voltages - but a reading of only 270mV is absolutley nothing to be worried about.

 

[Dazzy50]

Brilliant thanks guys. Yes it was on when I received my shock but I never realised there was an issue until then because that's what made me inspect the wiring.

Good to know there is a small amount of leakage to ground but its not a concern. And nope no shock anymore. Thanks.

 

[DaveHerns]

Is the circuit RCD protected ?

 

[ban-all-sheds]

Could it have been a static charge discharging through the machine's cpc?