Does a tumble dryer require its own socket?

[ericmark]

I have not got the tumble drier sharing the same socket as the washing machine, but that is a historical thing, done in the days when tumble driers were around 2 kW or more, today tumble driers use far less power.

To make a claim that tumble driers should not be plugged into a double socket without defining what type of tumble drier to scaremonger, is rather dangerous, as it means no one will take the slightest bit of notice to what their organisation says, as it is clearly out of touch with modern equipment.

I realise there may be old equipment still in use, but unless they make it clear what they are talking about, it would be better to say nothing.

 

[ebee]

It`s a matter of risk aversion.
Remove or reduce a risk makes sense.
Indeed, someone could use a car for for ages that could be described as a "death trap" and never actually come to harm but a few of them might do.
So I reckon good advice is not to put two (comparatively - when thinking of 13A on the high side for sockets) heavy loads on one socket, whether by using single sockets to stop the temptation or whether by using a twin socket but ensuring only a minor load on one side.
So if we avoid two of the higher loads and/or avoid the chance of them running simultaneously we should not have much of a problem.
Heating loads tend to be the higher loads (obviously a 35W soldering iron is actually a heating load but not much at all).
So the heavier the load, the longer it`s duration and the longer it`s overlap of usage.
Again a 10A kettle is a little high on usage but for how many minutes if the stat works - not long.
If we tend to think washer/drier/dishwasher and maybe ovens as the plug in items in this instance it gives us a half decent rule of thumb/back of a fag packet ort of approach in the first instance.
If we use multi-gang extension leads with items of 1/3/5 then they can add up to 13 or more so if predominantly permanent we might include them too as heavy loads.
Never use an immersion heater on a plug and socket (or a FCU) and always use it on it`s own dedicated circuit.
It boils down to a rule of thumb sort of idea - it is not set in stone.

 

[JohnW2]

I don't have a dog in "this fight" but as an OP, I would probably end up regretting asking a question...

I don't think that the OP has any reason to regret asking the question. He had read what is essentially a 'scaremongering recommendation' from the fire service, and, not unreasonably, wanted to know whether it actually related to a significant hazard (i.e. something that was 'not safe'').

Reasonable though the question was, answering it is not totally straightforward, because one cannot totally dismiss the 'recommendation', given that it is not totally impossible that the 'risk' being referred to could come to fruition. However, I think it reasonable to inform the OP that what is being recommended against is (and has been for decades) a very widespread practice,which I am sure has very very rarely resulted in any significant 'fires'. As I said, fires originating in the dryers themselves have undoubtedly been far more common than any relating to the plug/socket supplying them.

I do, however, agree that it is less than helpful for someone to potentially confuse the OP by quoting (incorrectly) guidance in an appendix of the regs (BS7671) that has absolutely nothing to do with 'overloading' and/or over-heating of the plugs/sockets supplying appliances.

 

[JohnW2]

It`s a matter of risk aversion.

Indeed it is, but ...

Remove or reduce a risk makes sense.

Up to a point, but excessive degrees of risk aversion do not really 'make sense'.

The world is, of course, full of risks, and where we (individually) place ourselves on the risk-averse/risk-taking spectrum is down to a judgement, which balances the degree of risk against the down-sides of measures to remove/reduce that risk.

We could, for example, minimise the risk of accidental injury by never leaving our homes, never doing anything which involved standing on anything other than the floor, never using any tools etc. etc. We could certainly effectively eliminate any risk of domestic electric shock by not having an electrical installation, and we could also virtually eliminate the risk of a fire originating in the building by having no electricity, gas or oil supply and by never allowing any 'naked flames' (or cigarettes!) - but one then could not cook (at least, indoors!)!

Hence, whilst I generally agree with the various specific 'cautions' you go on to mention, there is always a need to be sensible in keeping things in perspective, and hence not taking measures which are 'excessive' (in terms of cost, convenience or whatever) in order to minimise risks which are already extremely small.

Of course, as often discussed, "our" perception of the acceptability of risks has evolved dramatically over time. Many 'risks' which were fully accepted as being "part of life" only a few decades ago would today be regarded as unacceptable/'unthinkable', even when those risks would be no greater today than they ever were. Some of the movement in that direction is definitely (in my opinion) to be welcomed, but we all know of instances in which the situation today seems more than a bit "OTT" today!

Kind Regards, John

 

[SUNRAY]

Ah it has just occurred to me, I don't think this is about single or double sockets.

I reckon the statement to use it's own socket is all about not using double adapters.

Reason I mention it... neighbour has washing machine and kettle in one.

 

[ericmark]

I have just seen a BBC report on tumble drier fire and it says

Fire safety advice​

• Do not overload plug sockets - keep an eye out for any scorching or burn marks, including checking any visible electrical wires
• Do not leave appliances unattended – do not turn the tumble dryer on before you leave the house or go to bed
• Keep your dryer well ventilated, make sure the vent pipe is kink free and not blocked or crushed in any way
• Always clean out the filter after using your tumble dryer
• Always allow each drying programme, including the "cool down cycle", to complete fully before emptying the machine
• Do not ignore the warning signs – if you can smell burning or clothes feel hotter at the end of the cycle, stop using your appliance and have it checked out by a professional

I looked at the pictures, and one seemed to show a weight, so it would seem a washer drier, but some of the advice does not seem to make sense.
1) Should be impossible to overload a plug or sockets, they are protected with a fuse.
2) What is the point of a delay time start being built into the drier, if not used unattended, that is why the delay start function is built into the machine, so it can run using off-peak power.
3) This clearly depends on type, only the very old type has a vent pipe, but my cheap drier had a temperature switch and if the vent was blocked in any way it would trip, and the only way to reset was to drag the whole machine out, so there would need to be a design fault for a kinked pipe to cause a danger.
4) Yes, of course, I must admit easy not to clean them all out, my drier has 3, and two are easy to clean at the end of each cycle, but one is easy to miss.
5) I am not sure mine has a cool down cycle, clothes are quite hot when it has finished, it seems there are two temperatures 55ºC and 65ºC depending on the cycle selected, so not that hot to start with, using an energy meter it is clear it uses a mark/space ratio to maintain the temperatures, but some driers do work hotter, and it seems work clothes in driers have caught fire due to contaminates on the clothes, I would think it is referring to that, but not drying unwashed clothes would be better advice.
6) Yes, of course if you sense something wrong, needs to be looked at. But as an electrician, not sure what I could test?

I must admit the heat pump drier is not much cheaper to run as the old vented drier running at 1 kW setting, the old one took around 90 minutes, the new one around 2.5 hours, so looking at 1.5 kWh v 1.5 kWh but sometimes needed to restart the old vented drier, the new one has a built-in sensor, also when looking at the energy monitor the new one is using a mark/space ratio, so not using 600 watt for whole of the cycle, so it is cheaper to run, but not a lot.

However, it means the window can be closed, and the clothes are not as hot, so less creasing, and it has a delayed start function so can be set to use off-peak or solar power. The water removed goes straight into the drain, the other type of condenser drier, either wastes water, or heats the room it is in, since our utility room is so small, a drier using the room's air to cool it would not really work, the room would get hot far too quickly.

The driers seem to be:-
1) Vented which suck in air from the room, so humidity of the room will have an impact on performance.
2) Condensing using water, downside is it wastes water.
3) Condensing using air, downside is it heats the room it is in.
4) Condensing using a heat pump, downside is it takes longer.
The fire risk for the 4 is not the same, to not say which type is like lumping an air frier, a microwave, and a fan oven as all being ovens, they are clearly all ovens, but the safety requirements are not the same.

Ah it has just occurred to me, I don't think this is about single or double sockets.

That is also very true, I have two kettles on a 4 way socket bar, it should not be done, and I have blown a fuse once, but that's all, it blows the fuse, it does not set fire to the house. But a kettle, I am standing in front of it while it fills the cup, the washing machine, dishwasher and tumble drier I set to run then walk away.

 

[JohnD]

A tumble drier is one of the few appliances that can run at full power for an hour or more, continuously, so is more prone to cause overheating in plugs or sockets than most appliances.

 

[JohnW2]

Ah it has just occurred to me, I don't think this is about single or double sockets.

It shouldn't (have to) be. I think anyone has every right to believe that it is safe to plug a load of 13A or less into any '13A outlet', even if that outlet is one of two in a double socket. However, many people seem to believe that there is an issue with double sockets and, indeed, some seem to believe that (despite the BS1362 14A+6A test), double sockets are only 'rated' for 13A total (across both outlets).

We certainly do hear/see reports about these plugs/sockets sometimes suffering thermal damage. However, I'm sure that I'm not the only person to have seen that with single sockets (or even FCUs) used for 'large loads' (particularly immersions), and it seems most commonly due to poor connections to the fuse within the plug (or FCU) - so it may not (at least, not always) be anything to do with the fact that it's a double socket that is commonly affected..

I reckon the statement to use it's own socket is all about not using double adapters.

Yes, that is probably 'even worse'than a double socket!

 

[ebee]

However, many people seem to believe that there is an issue with double sockets and, indeed, some seem to believe that (despite the BS1362 14A+6A test), double sockets are only 'rated' for 13A total (across both outlets).

Yup. 13A total is the rating of the double socket but the type test on such a double (twin) is 14 + 6 for an adequate time and temperature rise , I see nothing wrong in that.

 

[JohnW2]

Yup. 13A total is the rating of the double socket ...

Well, you might believe that, but many people (including myself) don't - and the MK technical guys I've spoken to don't understand the 'ratings' in their Technical Datasheets, either ("because they are written by the marketing dept."!!).

The reason I personally don't believe that (at least for MK sockets), the 'rating' of a double socket is meant to be 13A total is that their documentation for sockets says that the 'rating' is ...

Current rating:
13A per socket outlet
(except 3 gang which is 13 amp in total)

That "except for..." would make no sense if the preceding "13A per socket outlet" also meant 13A total.

but the type test on such a double (twin) is 14 + 6 for an adequate time and temperature rise , I see nothing wrong in that.

I also would see nothing wrong with a test being 'more demanding' than the rating - but, as above, I personally find it hard to believe that the intention is that the 'rating' of a double socket is 13A total.

Kind Regards, John

 

[ebee]

I also would see nothing wrong with a test being 'more demanding' than the rating - but, as above, I personally find it hard to believe that the intention is that the 'rating' of a double socket is 13A total.

I believe the 13A is total otherwise it would be worded differently. I also believe that MK or any reputable manufacturer is able to make their products exceed the standard if they wish and good for them.
All I`m saying is what the standard does allow and without concrete evidence provided by the actual manufacturer that it actually exceeds the standard itself we must be prepared for the total to be 13A.
Some manufacturers I would not like to fit anyway but I assume that most who say they do conform actually do and, hopefully, it`s just a few foreign imports that do not.
One would hope that any standards are just the bottom edge of things and we further hope that in reality the better ones are substantially better than the standard actually requires but until/unless BS clarifies otherwise we must take the rated limit to be 13A total.
If we had a list of what all the manufacturers data sheets tells us then we could perhaps opt for the "better ones".

Has anyone asked all of the manufacturers if their understanding of the standards require 13A per outlet on a twin?

 

[DetlefSchmitz]

I am baffled as to how ebee forces the user of the double sockets he fits, not to load them with more than 13A. I can only assume he always powers it from an FCU. (This must look awfully ugly.) If this is not the case I can't see how he can claim to wire them up assuming a maximum of 13A. What we do know is that multiple sockets that really are only rated at 13A, contain an integral 13A fuse, which is of course not the case with any double socket I have seen.

 

[foxhole]

Tumble drier fires are usually the result of misuse , failure to clear filters regularly causing fluff to ignite on the heater element or drying items unsuitable ,my wife stuck a pillow in once which was labelled not suitable ( she is dyslexic ) and filled the laundry room with thick red smoke before she realised .

 

[JohnW2]

I believe the 13A is total otherwise it would be worded differently.

Hmmmm. Interesting - as I explained I do not believe the 13A is total because otherwise it would be written differently

I also believe that MK or any reputable manufacturer is able to make their products exceed the standard if they wish and good for them.

Indeed - and I would suggest that, in many walks of life, that is the norm. The real world being what it is, it would essentially be impossible to guarantee that one's product always "just" ('by the skin of it's teeth') satisfied a minimum requirement - so the only way of ensuring that it never falls short of that minimum requirement is to do things such that one always exceeds the minimum requirement, by at least a bit.

[ in some, perhaps now many, fields, 'Statistical Quality Control' is now acceptable. When that is the case, individual items of the product do not necessarily have to achieve the 'minimum requirement', but the average of a batch has to, with a statistical (probabilistic) definition of how far below that minimum individual items are allowed to be ]

All I`m saying is what the standard does allow and without concrete evidence provided by the actual manufacturer that it actually exceeds the standard itself we must be prepared for the total to be 13A.

Agreed - but, as I've said, my personal view is that MK's statement about 'ratings'indicate that they are saying that their double sockets exceed the minimum requirement of BS1363. Indeed, even were that not the case,they could (if their product is 'compliant') still at least say that its rating is 20A.'

One would hope that any standards are just the bottom edge of things and we further hope that in reality the better ones are substantially better than the standard actually requires ....

As above, unless the Standard allows for Statistical QC (which BS1363 does not), there is no realalternative to exceeding it's 'minimum requirement', since the alternative would involve unrealistic 'brinkmanship'!

... but until/unless BS clarifies otherwise we must take the rated limit to be 13A total.

I don't think that the Standard needs to 'clarify' that, since it already requires that a double socket can carry 20A 'safely' for a pretty long period of time. It obviously could not 'endorse' a higher rating than that unless its test were altered accordingly - but, as weve both said, there's no reason why a manufacturer cannot exceed the Standard's minimum.

If we had a list of what all the manufacturers data sheets tells us then we could perhaps opt for the "better ones".... Has anyone asked all of the manufacturers if their understanding of the standards require 13A per outlet on a twin?

As I've said, I've only asked the "Technical Support" folk at MK, and they did not know for sure what was the 'rating' of their double sockets

Kind Regards, John

 

[JohnW2]

I am baffled as to how ebee forces the user of the double sockets he fits, not to load them with more than 13A. I can only assume he always powers it from an FCU. (This must look awfully ugly.) If this is not the case I can't see how he can claim to wire them up assuming a maximum of 13A. What we do know is that multiple sockets that really are only rated at 13A, contain an integral 13A fuse, which is of course not the case with any double socket I have seen.

Exactlly.