Does a tumble dryer require its own socket?

[JohnW2]

Yes John, I am happy to agree with that in the main, not so much in opposition .

Fair enough. However, if you essentially agree with mw, then you really ought also agree that all these discussions about plugging two 'high' loads into a double socket, and all the arguments about what is 'the rating' of such a socket, are probably unnecessary, essentially a 'red herring'.

Like, I suspect, most other people, I've never really thought very deeply about this but, now I have done, I am coming more and more to suspect that the socket is largely irrelevant - i.e. if a 13A plug carrying a fairly high current comes to thermal harm (with consequent thermal harm to the socket) when plugged into a double socket when something else is also plugged in, I suspect that, in most cases, the same plug serving the same 'high' load would probably come to similar thermal harm (and hence thermally harm the socket) even if it were plugged into a single socket

Kind Regards, John

 

[JohnW2]

It is a good stance to take as a "Rule of thumb". Rules of thumb are just that and nothing else, the picture is far more complicated but rules of thumb have uses in general guidance.

True, but only if the 'rule of thumb' has some underlying validity. As I've been writing, I am coming more and more to so suspect that most of these concerns about double sockets may be nothing more than a long-perpetuated myth!

Kind Regards, John

 

[ebee]

Look, there is no such thing as a one size fits all rule in all manner of things.
Electrics, Plumbing, Driving Cars, Having a takeaway, going shopping, Going on holiday, taking medication, jadda jadda jadda ,
Each one contains risks along with ifs, buts and codicils.
Sticking to some golden rules may help us slightly in general , not sticking to them might not make a great difference in real life much of the time.
Do we stick to them as a generalisation? I vote yes it might help.

PS - I do not disagree with you mention of
" I suspect that, in most cases, the same plug serving the same 'high' load would probably come to similar thermal harm (and hence thermally harm the socket) even if it were plugged into a single socket"

 

[JohnW2]

Look, there is no such thing as a one size fits all rule in all manner of things. ... Electrics, Plumbing, Driving Cars, Having a takeaway, going shopping, Going on holiday, taking medication, jadda jadda jadda , Each one contains risks along with ifs, buts and codicils.

Yes, that's obviously true.

Sticking to some golden rules may help us slightly in general , not sticking to them might not make a great difference in real life much of the time.
Do we stick to them as a generalisation? I vote yes it might help.

That's fair enough if there is some evidence that application of the 'golden rule' may at least sometimes result in benefit (in relation to something which is not 'incredibly rare'. However, it ceases to be sensible if (as happens in most fields) it is based on some long-perpetuated 'myth' for which there is little, if any, evidence. We are all aware of suome such myths in relation to electrical matters ("it's what we have always believed") and I could give you many other examples fromother disciplines.

PS - I do not disagree with you mention of
" I suspect that, in most cases, the same plug serving the same 'high' load would probably come to similar thermal harm (and hence thermally harm the socket) even if it were plugged into a single socket"

Are you perhaps just arguing about my "most"? If you agreed that the overheating of plugs/sockets is 'nearly always' due to the plug, not the socket, then you would logically also agree that your 'golden rule' (about not plugging dryers etc. into a double socket) is essentially based on a 'myth', wouldn't you?

Kind Regards, John

 

[Harry Bloomfield]

That's fair enough if there is some evidence that application of the 'golden rule' may at least sometimes result in benefit (in relation to something which is not 'incredibly rare'. However, it ceases to be sensible if (as happens in most fields) it is based on some long-perpetuated 'myth' for which there is little, if any, evidence. We are all aware of suome such myths in relation to electrical matters ("it's what we have always believed") and I could give you many other examples fromother disciplines.

I think everyone has to, to extent, simplify their technical life, with rules of thumb/ golden rules - I certainly do. I only delve deeper, when I have a need to.

 

[JohnW2]

I think everyone has to, to extent, simplify their technical life, with rules of thumb/ golden rules - I certainly do. I only delve deeper, when I have a need to.

Of course - we inevitably all do that.

However, that does not remove the need to critically examine those rules of thumb to ensure that they are based on at least some relevant facts, rather than being 'myths'.

Many of the things I was taught during my initial professional education related to beliefs and practices that had been fully accepted for decades, but which have subsequently be found to be total nonsense, having never been anything other than myths.

In context, I can't recall having seen any case of thermal damage to BS1363 plugs/sockets that appears to have originated in the socket. If others have had similar experiences, that might suggest that it probably makes little, if any, difference whether the plug was plugged into a single or double socket - in which case the belief that there is a problem specifically related to double sockets may just be a 'perpetuated myth'. As I've said, although the reports (of thermal damage) we see/hear do commonly relate to double sockets, that may merely reflect the fact that double sockets are much more common than single ones.

I function in highly "evidence-based" fields, and I do have to wonder how much actual 'evidence' there is in relation to this issue.

 

[SUNRAY]

In context, I can't recall having seen any case of thermal damage to BS1363 plugs/sockets that appears to have originated in the socket. If others have had similar experiences, that might suggest that it probably makes little, if any, difference whether the plug was plugged into a single or double socket - in which case the belief that there is a problem specifically related to double sockets may just be a 'perpetuated myth'. As I've said, although the reports (of thermal damage) we see/hear do commonly relate to double sockets, that may merely reflect the fact that double sockets are much more common than single ones.

I function in highly "evidence-based" fields, and I do have to wonder how much actual 'evidence' there is in relation to this issue.

I have changed loads of heat damaged sockets, (if I have to put a figure I'l go for 200 - I kept a running total one year for BAS's benefit at 27) Of those 3 have been welded together so I suspect poor contact - one was a new MK DSSO and MK plug which lasted 12 weeks on a school water urn. I believe only one has been an overheaded socket and it was cracked but I don't know which problem caused thich damage. Of the rest heat damage around the line pin or wire/terminal.

 

[JohnW2]

I have changed loads of heat damaged sockets, (if I have to put a figure I'l go for 200 . I believe only one has been an overheaded socket and it was cracked but I don't know which problem caused thich damage. Of the rest heat damage around the line pin or wire/terminal.

Does that mean that you agree with my suspicion that the the problem nearly always arises in the plug, such that it makes very little difference whether the plug(s) carrying 'fairly large loads' are plugged into a single or double socket?

 

[FrodoOne]

Read a post in local paper re a tumble dryer fire.
Within the fire service advise they recommend a single socket for the dryer I.e. don’t share with another appliance.
Currently I share with a washing machine and they can easily both be on at the same time.
Is this safe?

Responses to this "Post" have been many and varied.
Glyn1959 has made only one later "Post".

I cannot see where anyone has ascertained if the "tumble dryer fire." was
a Fire in the Tumble Dryer
or
a Fire at the Plug/Socket.

(A "Post" or reference to the "local paper" article may be of assistance, Who knows?)

Apart from under-rated extension leads,
any "Socket-Outlet is likely to be the weakest link in any electrical distribution system.

While the "Pins" of a "plug" (especially BS 1363 plugs") are of a "heavier gauge" than the conductors which supply and utilize them,
the "Socket-Outlet" contacts are the "limiting factor" - in that they impinge on but a small area of each "Pin", albeit on both sides.

The quality and tension of the metal used in such contacts is an important factor -
since a "loose-connection" will result in local heating,
which may lead to "softening" of the metal,
reducing the "conductance" of the connection
leading to further heating
and
so on?
(The connections on a re-wireable plug could also be a problem, if they have not been tightened correctly.)

I would recommend that,
whenever a "high energy using" appliance
(Tumble Dryer, Iron, Toaster, Vacuum Cleaner, Hair Dryer etc.)
has been used,
the user immediately removes the Plug from the Socket-Outlet and
checks the temperature of the Line and Neutral "Pins".
If either pin is more than "just warm" and especially if one pin is warmer than the other
there is a problem with the tension of the Socket-Outlet contacts
and
that Socket-Outlet should be replaced.

(See also Post #15)

 

[SUNRAY]

Does that mean that you agree with my suspicion that the the problem nearly always arises in the plug, such that it makes very little difference whether the plug(s) carrying 'fairly large loads' are plugged into a single or double socket?

Yes totally B U T I'll habitually aim to keep the total load on a double socket to around the 3KW level.
However in the old days when men were men and sockets were sockets we managed to get a license to use fuseless 13A plugs and 4KW on a 15A MCB was a fairly standard 'entertainment' load.

Yes, on page 1 I mentioned the problem is our horrible plugs which overheat.

...In my experience it's more common for the plugs to overheat which then burns the socket frontplate, as such I would say the good thing to do is just feel the plugs when been in use for a little while (say 10-20 minutes) to see how warm they get. If they get hot then come back here and ask for further advice.

... I guess I was just indicating the biggest issue is the presence of the fuse/the way it's fitted. Without it the connector is very likely to handle the full rated current without problems

What I'm really saying is our BS1363 plugs are not fit for purpose, especially those with fixed pins (such as MK) which can stress the socket contacts. However I have many plugs and sockets from 50's and 60's which I treasure as they are built so much better than modern ****

 

[ericmark]

I have only seen one reply from @Glyn1959 and we have no idea what type of tumble drier. Out of interest, I Googled Tumble dryer, the vented only gives kWh no loading, the heat pump "Total Electricity Loading (W): 900" I found a Bush Condenser tumble dryer which stated 2700 watts in the user's manual. Again a Bush (TD3CNBW) this time vented and 1020 watts, I had not realised condenser types used more than vented.

As second Bush vented (DHB7VTDW) showed 1800 watt. I was losing the will as it seemed so hard to find how many watts they use. But it did surprise me to find the variation between them.

My old vented tumble dryer was really cheap, no bells and whistles, simple set drying time, and it would auto switch off after that time. But the heat pump one, which replaced it, has all sorts of features, I see no easy way to compare the two as to possible fire risk, as so different. Be the risk of the plug, or whole machine.

As to how they preformed, the new machine typically dries in 2.5 hours, the old one in 90 minutes plus, that was the timer limit, often put on for a second time, as clothes not fully dry. But 1000 v 600 watt, since the new one switches the heater on/off during the cycle, it is not a case of 600 x 2.5 hours to work out the kWh used to dry a load, the drum seems to use a fair bit of energy to turn and blow, so still using power when heat pump off, but not as much.

The main advantage is being able to close the window, it is a small utility room, so an air cooled condenser drier would get the room rather hot, so for me no real option but a heat pump type, or of course a core drill and a hole in the wall.

But without knowing the details of the drier, can't see how the question can ever be answered.

 

[JohnW2]

Yes totally ...

Thanks for confirming, but ....

.... B U T I'll habitually aim to keep the total load on a double socket to around the 3KW level.

Is that 'habitual behaviour' not based on what I am suggesting is perpetuation of a myth?

If the problem of overheating is, in practice, nearly always due to the plug then there is no reason to think, per se, that the problem would be significantly less likely to occur if a plug was plug (carrying 'high current' was the only one plugged into a socket than if it were plugged into a double socket with total loads approaching 26A (or, at least 20A)

What I'm really saying is our BS1363 plugs are not fit for purpose...

Exactly. If the overheating problem nearly always originates in the plug (and with a current no more than 13A), then there is nothing (particularly not the socket) other than the plug to blame.

As for 'overloading the socket', and all the arguments about the 'rating' of a double socket, in addition to all the above, I think people are probably not correct in seemingly assuming that double sockets only just 'scrape through' the BS1363 14 A + 6 A temperature rise test. I may be wrong, but I strongly suspect that most double sockets 'sail through' the test, with a temp rise (at 20 A total) well below the Standard-permitted maximum - so that they would quite probably 'also pass the test' (not exceed the Standard-permitted max temp rise) with 26 A total, or more.

 

[ericmark]

What I'm really saying is our BS1363 plugs are not fit for purpose, especially those with fixed pins (such as MK) which can stress the socket contacts. However I have many plugs and sockets from 50's and 60's which I treasure as they are built so much better than modern ****

Our 13 amp system has been altered, with insulators on the pins, which reduce the heat transfer, but also we have non-compliant fuses, which in some cases are near impossible to see they are fake without breaking them, and also non BS1363 lumps of plastic forced into the sockets, straining the contacts, and heavy transformers, hanging from sockets, and other abuse, is there any wonder why they fail.

It is typical to see the damage to the line pin where the fuse is, ⁣ but rare that we actually look as to why. I am no angel not overloaded, nothing of any size plugged in, but the bottom adaptor has no fuse, OK as there is a fuse in the plug for the extension, but we all abuse the system, then wonder why it failed.

 

[SUNRAY]

Thanks for confirming, but ....

B U T I'll habitually aim to keep the total load on a double socket to around the 3KW level.

Is that 'habitual behaviour' not based on what I am suggesting is perpetuation of a myth?

it's to do with so many double sockets stating 'total load 13A' or some variation

 

[JohnW2]

it's to do with so many double sockets stating 'total load 13A' or some variation

Indeed it is, hence all the discussion/arguments. The specs are frequently ambiguous, particularly in that they often refer to 'socket outlets' without explicitly defining what that means. Common sense seems to suggest that a double socket has two 'outlets', in which case, for example, MK's spec of "13 A per socket outlet" presumably means 26A total - a view which seems to be reinforced by the fact that they go on to add "except for triple sockets, for which the rating is 13A total)".

However, for a start, a double socket which could only safely (in terms of temp rise) carry 13A total would not even pass the BS1363 temp-rise test - and, indeed, any double socket which passed that test (which it has to do to be BS1363-compliant) would be able to carry at least 20A total.