70 volt potential from appliances to earth

[winston1]

[QUOTE="mikeymo, post: 3934630, member: 29298]

1. Is it OK to have, as there is currently, a fused spur (for lights) AND an unfused spur (for the appliance double socket) coming from the same ring socket?[/QUOTE]

Yes.

2. If a single socket is designed for 13 amps, why wouldn't a double be designed for twice that?

Some are, many are not. It comes down to manufacturer penny pinching on the (false) assumption that people would not put two 13 amp loads on a double socket.

 

[JohnW2]

Some are, many are not. It comes down to manufacturer penny pinching on the (false) assumption that people would not put two 13 amp loads on a double socket.

It does seem very odd, but the manufacturers have presumably been able to do it because BS1363 requires them to pass the temperature rise test only at 20A (seemingly rather strangely, 14A + 6A!).

If I recall correctly, our previous attempts have failed to find any double socket which are explicitly stated to be 'rated' for 26A total (2 x 13A) continuous. MK, who at least used to be one of the most reputable and responsible manufacturers have said that their double sockets suffer significant thermal damage at continuous loads above 22A total - so, despite the ambiguity of what their Technical Data Sheet says, they presume do not consider those sockets to be 'rated' at 26A total..

Kind Regards, John

 

[Albumen]

Thanks very much for all your comprehensive replies.

So the way forward:

Immediate future - find what's causing this 70 volt 'leak' and fix it. Presumably dodgy socket, or dodgy connection to ring main. Electrician coming tomorrow. then:

Medium term - plug washing machine into ring main socket. Ugly but doable. Tumble dryer into spur socket. Or continue using double socket for both, but instructions to household not to run both appliances simultaneously. Not too onerous, it's summer now, so washing line and sun means not much call for tumble dryer.

Long term - The double socket which up till yesterday was supplying the two appliances is under the sink, on the wall. It is accessible, if you get on your hands and knees and move the bucket and don't mind banging your head on the sink. Seems to me the spirit of the regs are being contravened here, the isolating switch isn't really accessible to somebody operating the appliances. Specifically if there was a problem with either (and tumble dryers have been catching fire recently), the last place I would want to be grovelling round to turn if off is right next to it. The only other way of turning off power would be the MCB in the consumer unit. Which is awkward, and even if I could remember which one it is, I'm not sure anybody else in the house would.

So this solution: Spur from ring main socket to isolator switch. Then on to two separate single sockets. Maybe reposition them so they are above the worktop and away from all the potential sources of water. Advantage of an isolator is it would be fairly near door. So it would still be possible to turn either off without going right into the room. I could even position said isolator so it's just inside door. Does this sound like safest solution?

 

[EFLImpudence]

Long term - The double socket which up till yesterday was supplying the two appliances is under the sink, on the wall. It is accessible, if you get on your hands and knees and move the bucket and don't mind banging your head on the sink. Seems to me the spirit of the regs are being contravened here, the isolating switch isn't really accessible to somebody operating the appliances.

There is no requirement for local isolation - but pulling out the plug is an excellent method.

Spur from ring main socket to isolator switch. Then on to two separate single sockets. Maybe reposition them so they are above the worktop and away from all the potential sources of water. Advantage of an isolator is it would be fairly near door. So it would still be possible to turn either off without going right into the room. I could even position said isolator so it's just inside door. Does this sound like safest solution?

You are talking about emergency switching; not what is meant by isolation.
If you consider this necessary then you may fit switches wherever you want.

 

[aptsys]

Agree that you have almost certainly lost the earth on the double socket.

But you should not run a washing machine and tumble dryer off the same double socket. You may get away with it if you don't run them both at the same time, but can you guarantee that?

You're making a few assumptions there. My tumble dryer doesn't draw more than 1kW...

 

[EFLImpudence]

...and 13A washing machines are unlikely these days, too.

 

[Albumen]

There is no requirement for local isolation - but pulling out the plug is an excellent method.

You are talking about emergency switching; not what is meant by isolation.
If you consider this necessary then you may fit switches wherever you want.

Thanks. Sorry used wrong term. 'Turn it off when all hell breaks loose' was the expression I was searching for.

Nobody's going to be pulling the plugs under the sink out every time we stop using one of the applicances.. Especially as we all get creakier. It's just not going to happen. So a switch like the one that goes to my built-in microwave or extractor hob would do the job? Or a 32amp one, like for the oven?

I'll have a look at the back of the applicances if I can, see what they draw. The washing machine is cold supply, so there's a heater in it.

Thanks

 

[ban-all-sheds]

Nobody's going to be pulling the plugs under the sink out every time we stop using one of the applicances.. Especially as we all get creakier. It's just not going to happen.

Precisely.

So how often do the owners of appliances like that isolate them?

So a switch like the one that goes to my built-in microwave or extractor hob would do the job?

Yes, but and maybe.

The microwave switch might be a switched FCU, and two fuses for your appliance would be superfluous.

The extractor switch might be ditto, or if it's on the lighting circuit it might be a light switch, which would not do for a laundry appliance.

Or a 32amp one, like for the oven?

It does not need to be able to cope with that much current.


In fact, it does not need to be there at all. If you want switches, to give you a capability which the millions of people who have appliances plugged into hard-to-reach sockets seem to manage perfectly well without, then by all means have them. But don't go putting them in because you think you must have them.

 

[Albumen]

I'll use a 32 amp cooker one then. It was that recent headline - 'Family dies horrible death in house fire because father unable to turn power off to blazing tumble dryer' that gave me the idea

http://www.mirror.co.uk/news/uk-news/spinflammable-washing-machines-biggest-cause-5882657

 

[EFLImpudence]

...but would it have made any difference?

How would switching of the power have any affect on a blazing appliance?
I suppose it may - depending on the cause - have prevented the fire, unless it caught fire during normal operation.

Anyway, 'tis up to you.

 

[JohnW2]

... 'Family dies horrible death in house fire because father unable to turn power off to blazing tumble dryer' that gave me the idea

To be honest, once an electrical appliance is 'blazing' I don't think turning the electricity off would make any significance difference, fire-wise, although there are other reasons why it's probably desirable so to do. More important than looking for electrical switches/isolator is to 'get out quick'!

Kind Regards, John
Edit: fractionally too slow ..... again

 

[Albumen]

To be honest, once an electrical appliance is 'blazing' I don't think turning the electricity off would make any significance difference, fire-wise, although there are other reasons why it's probably desirable so to do. More important that looking for electrical switches/isolator is to 'get out quick'!

Kind Regards, John
Edit: fractionally too slow ..... again

Who knows what happens in an unlikely emergency scenario. One thing that turning the electricity off would do is make it safer to use water to put the fire out. Maybe by that point the RCD would have tripped anyway.

Still, when my mothers old electric heater caught fire a few years back she was able to pull the plug out. I couldn't do that with the appliances the way they are at the moment. Isolators are required on hobs and suchlike as they are 'hardwired', and part of that reason is safety, isn't it? These two appliances are on their way to being 'hard wired', given the position of the plugs.

Anyway, thanks for the advice folks, I'll have a think. If there's going to be a bit of work to do, I can't see it'll do any harm. And I may be one of the 3169 people a year whose washing machine or tumble dryer catches fire.

 

[winston1]

Isolators are required on hobs and suchlike as they are 'hardwired', and part of that reason is safety, isn't it?

Isolators are NOT required on hobs and suchlike. People often fit them but there is no requirement to do so.

 

[Albumen]

Isolators are NOT required on hobs and suchlike. People often fit them but there is no requirement to do so.

I stand corrected, deepest apologies. Just wondering then, did the electrician who did my kitchen rip me off? There's 4 switch type things for the oven, hob, microwave and extractor? Hope I didn't shell out unnecessarily.

 

[JohnW2]

Who knows what happens in an unlikely emergency scenario. One thing that turning the electricity off would do is make it safer to use water to put the fire out.

Indeed - that is one of the 'other reasons' (other than doing anything to the blazing fire) I eluded to for switch off the electricity being desirable.

However, as I said before, if something is already 'blazing' in one's house, the thing to do is probably to get out, not to try to put the fire out!

Kind Regards, John