Electric shocks from new washing machine

[Clive Page]

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?

[js.b1]

If the earth is broken or high impedance, the mains filter will create a low current (up to 1.5mA) leak to the machine's case.

The fault is thus with the lack of earthing since the machine is probably class-1 ("Must Be Earthed").

Check the earth continuity for that final circuit, check MEB is present & correct, check supplementary bonding etc. If the area is prone to damp, solid floor, perhaps add RCD.

Also, use new hoses not any old original (they fail eventually :-)

[Harry Bloomfield]

on 17/11/2009, Clive Page supposed :

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.

[Roger]

The fault is with his socket and/or house wiring.

You should not use the appliance without having the wiring fault in the house rectified. You could kill him by not acting.

Why would a shop replace a new product because a person chose to use it with faulty and/or unsafe sockets and/or wiring in a house?

[Roger]

Good advice, i have seen this so many times with old and damaged wiring. The best was someone who had a firework display using a washing machine and also had incredible electric shocks reaching in to a chest freezer. It is the socket and/or wiring in the house that is faulty. It seems stupid to ask about changing a product but leaving faulty wiring and/or sockets! Buy a socket tester, then get it sorted before you see the person killed. I saw one person who had a wiring fault after he touched both taps to put water in a sink, he was dead as the current flowed up one arm and down the other. Others I have seen with some nasty burns, one person even jumped backwards and hit a worktop with a knife on it! Cuts and burns are easier to treat - bringing someone back to life is a touch more difficult.

[ARWadsworth]

Paramedics see far less deaths and injury due to electrical faults than you have!

I have seen some bad wiring faults in my time but they have caused no deaths.

I did see a worktop with a knife on it last week. I forgot to inform the emergency services as I was busy washing up at the time.

Roger

.

[ARWadsworth]

Indeed. Unplug the machine until the socket is tested.

Adam

[Clive Page]

In message , Roger writes

Well as I said in my original posting, obviously I suspect the house wiring and have told him to use it only when plugged into a different socket until that one has been checked and fixed.

I was surprised about the leakage from mains to earth in the appliance, but others suggested that modern appliances have a mains filter which has that effect. Thanks - that's news to me, though maybe I should have guessed.

I suppose one could think of the effects of that leakage as a useful warning: if you plug the washing machine into a socket with a poor earth the shocks you get warn you that something is wrong. The old one, now defunct, didn't do that.

[The Medway Handyman]

Just asked my paramedic daughter about that. In 4 years of frontline duty she has attended just 2 cases of electric shock. One was a bloke who was woken by a mains smoke alarm. To silence it, he stood on some metal kitchen steps (barefoot) and used a pair of metal kitchen scissors to cut the cable. He also managed to stab himself in the leg - twice - whilst falling off the steps :-)

Thats a brain fault, not an electrical fault. The other one was faulty wiring.

[ARWadsworth]

It might be a brainfault but it is bloody priceless:-)

Adam

[GMM]

like that trip an RCD, ie take out any newly wired house? Or am I misunderstanding something (which is always very likely!)

[GMM]

You never never have a video camera handy when you need one - He could have become a youtube star......

[Bruce]

The original poster did say that the wiring had been in place for

30-40 years (you quoted the text, above). So it is quite likely that no RCD was fitted.

[Harry Bloomfield]

GMM explained :

The leakage has to be of a sufficient value, before the RCD will trip. Filters, though of sufficient leakage to provide a mild shock, do not provide enough leakage to trip the RCD. The exception is when a number of the filters are used on the same circuit, where the leakage adds up and can be enough to cause a trip, or cause nuisance tripping.

[GMM]

the technologies here. Maybe I should stick with the old re-wireable fusebox with a few nails in place of the fuse wires after all!

[Dave Plowman (News)]

My long dead mother did something similar in the early stages of Alzheimer's. She couldn't remember how to stop her electric alarm clock from buzzing so cut the flex with scissors. Luckily only suffered a minor burn. The alarm was on one of those pukka clock sockets which need a nut removed before they can be unplugged.

[John Rumm]

Now that is a special kind of stupid!

[John Rumm]

Its not the leakage to earth that is the problem, but the fact that the filter is wired N-E-L. That means if the earth is not actually earthed, then the casework will tend to rise to half mains voltage.

One way of looking at it I suppose!