A twin socket with two way “death cubes” alarms a bit though 

My washing machine and tumble dryer together cannot take 20A total for very long, washing takes 13A for perhaps 15 minutes, the tumble dryer 7A for half an hour. I do not see why there is any problem, neither the socket nor the plugs hardly become warm. Perhaps if they are old, dirty, and corroded there may be a problem, but it is certainly not generic.

some manufacturers build their products to be rated in excess of the standard. BS1363 requires a double socket to be rated for 13A for the accessory, not per socket. The better quality brands you will “get away with it”, the cheap ones, maybe not. 

Regards,

Alan. 

davezawadi (David Stone): 
 

My washing machine and tumble dryer together cannot take 20A total for very long, washing takes 13A for perhaps 15 minutes, the tumble dryer 7A for half an hour. I do not see why there is any problem, neither the socket nor the plugs hardly become warm. Perhaps if they are old, dirty, and corroded there may be a problem, but it is certainly not generic.

Tumble dryer must be on half heat - the elements are usually 2 kW or more for full heat. Ours gets used for drying towels mainly (kids activities), along with other cottons, so often used on full heat.

That's where the problem arises.

Agree if you almost always use half heat it won't be much of a problem.

Alan Capon: 
 

some manufacturers build their products to be rated in excess of the standard. BS1363 requires a double socket to be rated for 13A for the accessory, not per socket. The better quality brands you will “get away with it”, the cheap ones, maybe not. 

Regards,

Alan. 

Is it the case that manufacturers declare a higher rating any more? I know it was the case, but I'm struggling to find one now that is … then again, of course we are less likely (but not unknown) to use the 3 kW  portable fan heaters now, so perhaps a sign of the times.

As far as I know none of them declare it anymore, although I don’t think the two that did have changed their designs. 

Regards,

Alan. 

Just before anyone else points it out, pedantically, 3 kW (rated at 230 V) is slightly over 13 A and we might point out it shouldn't be used with a BS 1363 plug

… but 3 kW (rated at 240 V) which is the rating of my younger days, is only 12.5 A.

The design of the heaters hasn't changed (still 19 ohms with all elements switched on at operating temperature or thereabouts), so the same appliance that used to be rated '3 kW at 240 V' would now be rated '2.8 kW at 230 V'.

And before anyone thinks we're now being more energy efficient, the actual supply voltage didn't change at all when we went over to 230 V from 240 V …

Chris Pearson: 
the washing machine and tumble drier have run off another double socket for 25 years without ill effect.

gkenyon:

You are fortunate. I've seen, sadly, cases of washing machine and tumble dryer connected like this, where plugs and socket-outlets (and sometimes both together) have been damaged by overheating in as little as a year. Various manufacturers' products.

I have just checked. Drier is 2850 W and washer 2400 W.

I have no idea how often the drier's thermostat will cycle the heating elements, but it goes continuously for up to 40 min.

The washer uses 49 kWh per 100 washes so it clearly cannot use full power for more than about 10 minutes per wash.

__________________

It's all very well debating the rating of a 13 A wiring accessory, but IMHO there is no reason why an ‘ordinary person’ should not reasonably believe that any domestic appliance may be plugged in safely to any 13 A socket outlet.

In fact I shall go further. There is no reason why an ‘ordinary person’ should think about the consumption of domestic appliances.

In fact I shall go further. There is no reason why an ‘ordinary person’ should think about the consumption of domestic appliances.

They should, as they are going to be the ones paying the bills.

Chris Pearson: 
but IMHO there is no reason why an ‘ordinary person’ should not reasonably believe that any domestic appliance may be plugged in safely to any 13 A socket outlet.

In fact I shall go further. There is no reason why an ‘ordinary person’ should think about the consumption of domestic appliances.

If we think that is the case, it's a good reason to prohibit all of the following then:

• Double BS 1363 plug-in adaptor (unfused)
• Double (and triple) socket-outlets
• Multiway adaptors (why should the ‘ordinary person’ have to go to the trouble of thinking about the fuse operating, and replacing them with the correct value)?
• Ring final circuits (sticking to 16 or 20 A radials) … and then we can get away with the BS 1363 fused plug, and the wasted energy of the heat from fuses in those too 

But in all seriousness, we are talking about large movable (but not really that portable) appliances, where proper provision (in terms of space, ventilation, and perhaps other semi-permanent utility connections) are made.

Installation of these appliances is not trivial either (it might be to many on this Forum, but not to the public at large).

So … it's not really the ‘ordinary person’ who needs to worry about that.