On 17 Nov, 22:02, Harry Bloomfield
wrote:
on 17/11/2009, Clive Page supposed :





My elderly father has just bought a new AEG-Electrolux washer-drier. *It was
delivered yesterday and I helped him get it installed and working. While
adjusting the feet with my hand between the casing and the concrete floor I
noticed a distinct tingling, until I disconnected the machine from the mains.
*I thought that was odd, and wondered if the earth connection was not quite
right. *But I was running late and keen to get home, so didn't follow it up
at the time, unfortunately.

This evening my father phoned me to say he got a distinct shock from the
metal barrel when unloading a new batch of clothes. *Although his faculties
aren't as acute as they were, he's a retired electrician so fully aware of
the difference between a mild and a more serious electric shock. *From his
description over the phone, it sounded like the latter.

The machine is in a back porch, and the mains socket has been in place for
maybe 30-40 years, so it might have a corroded earth connection - something
I'll obviously follow up as soon as I can.

Meanwhile I told him to try the machine on an extension lead so it can be
plugged into somewhere else in the adjacent kitchen, which ought to be ok. *
If the leak between live and the metal casing of the machine is really large
it ought to blow a fuse or two when properly earthed.

Appliances like washing machines are clearly designed to be used when earthed
properly, but I assume they must be designed to be reasonably safe even when
accidentally used without a proper earth connection. Does anyone know if
there are rules on how much current can be allowed to leak from live to the
metal casing?

Also - even if it turns out to be badly earthed, is there a case to be made
that the machine is faulty and should be replaced by the shop if one gets a
detectable shock from it?

The shock could have been from a fault where by the ground is live and
the casing of the washer is properly earthed - just something to keep
in mind.

Now assuming the more likely shock from the case of the machine.
Machine these days are microprocessor controlled, so it will have a
filter on its mains input. The filter has some leakage to its earth
connection and if the machine lacks a proper earth, it would then be
possible to get a slight shock by touching the case and a ground.

Most likely scenario is the the socket you have plugged the washer in,
lacks an effective earth. Attend to it as a matter of urgency.

--
Regards,
* * * * Harry (M1BYT) (L)http://www.ukradioamateur.co.uk

That's interesting: Never knew that before but wouldn't earth leakage
like that trip an RCD, ie take out any newly wired house? Or am I
misunderstanding something (which is always very likely!)