Does a tumble dryer require its own socket?

[SUNRAY]

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, View attachment 351054and heavy transformers, View attachment 351055 hanging from sockets, and other abuse, View attachment 351056 is there any wonder why they fail.

It is typical to see the damage to the line pin where the fuse is, ⁣ butView attachment 351057 rare that we actually look as to why. I am no angelView attachment 351058 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.

None of your pictures are different to the way other European countries plethora of sockets are mistreated, in fact I'll go further and say they tend to use far more multiway and interseries adapter than us and they don't seem to have the heating we do.

 

[DetlefSchmitz]

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

You do surprise me. I'd love to see a photograph.

 

[SUNRAY]

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.

But there is nothing to stop manufacturers marking as 13A max

 

[SUNRAY]

You do surprise me. I'd love to see a photograph.

I'll keep my eyes open for you.

 

[JohnW2]

Our 13 amp system has been altered, with insulators on the pins, which reduce the heat transfer, but also we have non-compliant fuses ...

True, but I think the 'autopsy evidence' usually suggests that the problem is commonly the connection between the fuse and its holder- particularly those cases in which that connection is achieved by 'jamming' the fuse into a hole in a bit of brass, rather than having a 'sprung' connection.

 

[JohnW2]

But there is nothing to stop manufacturers marking as 13A max

Indeed not - but they would be a bit daft to do so (deliberately) if that represented an understatement of their product's capabilities.

Similarly, as often discussed, there is also nothing stopping them specifying the rating as 26A (if that is true), even though BS1363 does not require testing at such a current.

 

[SUNRAY]

True, but I think the 'autopsy evidence' usually suggests that the problem is commonly the connection between the fuse and its holder- particularly those cases in which that connection is achieved by 'jamming' the fuse into a hole in a bit of brass, rather than having a 'sprung' connection.

I'd say the sprung clip is the bigger problem as it goes through multiple heating and cooling cycles. There is a term for it; annealing.

 

[ericmark]

Without smashing open, could you work out which is fake? Some we can see as fake, ⁣

but although we know you can't get a BS1362 fuse at 15 or 20 amp, would the man in the street know?

 

[JohnW2]

.... Without smashing open, could you work out which is fake?

Presumably not - but do you really believe that 'fake' ones are going to get any hotter, with a given current, than a non-fake one

 

[ericmark]

You do surprise me. I'd love to see a photograph.

The filter sockets, and other specials are quite often rated at 13 amp for the pair, I think this is wrong, but.

so yes MK Logic plus filter socket rated 13 amps for the pair, not per socket outlet as with non specials.

 

[JohnW2]

The filter sockets, and other specials are quite often rated at 13 amp for the pair,

They seem to be, but (as you illustrate) that's not the case with the ordinary MK sockets.

However, that does indicate that MK DO write "13A total for two sockets" when that is what they actually mean, which strongly suggests (at least, to me) that their "13A per socket outlet" means 26A total for a double socket

 

[DetlefSchmitz]

The filter sockets, ... are quite often rated at 13 amp for the pair, I think this is wrong, but.

Yes, that's because the two sockets share a 13A filter element.

 

[SUNRAY]

View attachment 351061 Without smashing open, could you work out which is fake? Some we can see as fake, ⁣ View attachment 351062but although we know you can't get a BS1362 fuse at 15 or 20 amp, would the man in the street know?

Now going back a long way there was a well known fuse manufacturer who did make fuses which conformed in every respect to the BS1362 standard except they made up to a higher rating, I feel16A although being so far back I'd not make it a statement.

 

[FrodoOne]

Our 13 amp system has been altered, with insulators on the pins, which reduce the heat transfer,

While the half-insulation may "reduce the heat transfer", I do not believe that any such reduction would be "significant".
The pins on a BS 1363 plug are 4 mm (0.16") thick and 6.35 mm (0.25") wide.
[In comparison, Australian plugs have pins of 1.6 mm (0.06") in (total) thickness - and are also 6.35 mm (0.25") wide.
The "half insulation" reduces the thickness of the "metal component" in each shank to about 1 mm, a 0.6 mm reduction.]

If the thickness of the half-insulation on a BS 1363 plug is similar in thickness, there would still be 3.4 mm thickness of metal - 85 %
(See https://www.dimensions.com/collection/electrical-plugs-sockets )

While I wrote (Post #69):-

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.)

SUNRAY (Post #82) identified a similar problem in relation to the fuse-holder, which I had not considered:-

I'd say the sprung clip is the bigger problem as it goes through multiple heating and cooling cycles. There is a term for it; annealing.

 

[ebee]

Depending upon the quality/tightness of spring of the fuseholder is, in my humble opinion, often the most significant factor in the plugtop which in my view again is quite probably the most significant factor of plugtop overheat therefore also of socket overheat.
Some plugtops are carp as are some sockets quite frankly and yes a factor of insulating plugtoptop pins must make some difference to heat loss due in part to the insulation itself and also the reduction of CSA of the pin conducting mass.
The only action we can take to mitigate this is to use propriety plugs and sockets wherever possible.

I still believe the 13A rating as per BS is 13A per single or twin but that does not mean I think that they could burst into flames at 14A etc, seeing as the rating is 13A then we can either use single sockets if we think appropriate (extremely rare for me) or placing twins in a position to encourage rather than discourage the use of two "heavy" appliances and to mention this to the user, if we all did that then I guess it could reduce risk, albeit ever so slightly, in total.

I usually use 25mm boxes rather than 35mm unless there is some other reason for using 35mm or greater but I do reckon this in itself could in some small way increase heat loss in some instances possibly making a difference, although in my opinion it is the quality of the goods that is the most significant factor along with the soundness of connections to.