broadgage: 
 

Is there any reliable information as to the current rating of a twin 13 amp socket.

I have a record and this is it below; from whence it came I know not, probably a BS but search and ye shall find. 

The test current is 14A for a single, 20A for a double (14A + 6A), and the duration is 4-8 hours. 
Maximum temperature should be no more than 52ºC.

jaymack

We have been here before - search the forum!

All I would say is that every morning I make toast and tea using the same double socket. OK, that's short duration, but the washing machine and tumble drier have run off another double socket for 25 years without ill effect.

Yes, tested to 14 A + 6 A for 4 hours. 20 A is going to cost about £1/hour!

Jaymack: 
 

broadgage: 
 

Is there any reliable information as to the current rating of a twin 13 amp socket.

I have a record and this is it below; from whence it came I know not, probably a BS but search and ye shall find. 

The test current is 14A for a single, 20A for a double (14A + 6A), and the duration is 4-8 hours. 
Maximum temperature should be no more than 52ºC.

jaymack

 

That's not quite the case … the single outlet is tested for a current of 6 A on the ring + 14 A from the outlet itself.

broadgage: 
 

Is there any reliable information as to the current rating of a twin 13 amp socket.

Sounds simple enough, but views seem to differ. I was taught (decades ago) that a twin 13 amp socket manufactured to the relevant standards was suitable for a total load of 20 amps. And I recall that approval testing was done with 14 amps on one outlet and 6 amps on the other.

More recently though I recall respected members of this, and other forums, stating that the maximum total load is 13 amps and not 20 amps. And yes I know that 13 amp twin sockets  are marked “13 amps” on the back. But does this mean “maximum total load of 13 amps” or does it mean “intended to accept 13 amp plugs”

Any reliable views on this, preferably with a source.

And related to the above, I have heard that MK twin 13 amp sockets go beyond the minimum standards and are designed for a total loading of 26 amps. Can anyone confirm or deny this. And yes I have asked MK and have received several different answers !

Yes, the service rating of a single socket-outlet is 13 A.

The rating of a double socket-outlet is 13 A.

The standard requires this to be marked on the product.

Chris Pearson: 
 

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

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.

gkenyon: 

That's not quite the case … the single outlet is tested for a current of 6 A on the ring + 14 A from the outlet itself.

Is that a single outlet as in a one off socket, as opposed to a single socket on a twin socket ?

Jaymack 

Jaymack: 
 

gkenyon: 

That's not quite the case … the single outlet is tested for a current of 6 A on the ring + 14 A from the outlet itself.

Is that a single outlet as in a one off socket, as opposed to a single socket on a twin socket ?

Jaymack 

The single-outlet on a ring is loaded as I said, 14 A through the socket-outlet itself, with a further 6 A passing through the terminals on the rear to represent the considered usage in a real circuit.

In a twin socket-outlet, the loading is 14 A on one outlet, 6 A on the other.

But both devices are still rated 13 A continuous use total - that means the 13 A twin outlet is 13 A total through both outlets. 

Because of what I've seen in the past with overheating of double socket-outlets, and considerations about point loading on circuits, particularly ring finals, I would always recommend appliances that are capable of using 2 kW or more, whether intermittently, or continuously, to have their own single socket-outlet.

Graham, I`m sorry to be a right pain in the neck, but could you clarify that “13 A total through both outlets. ” means both each running 13A or both in total running 13A. My understanding that the point itself was 13A total whether twin or single or multiple.

PS I think I got it rereading what you said

The casual observer might notice that BS 1363's requirement for adaptors allow 2-way ones to be unfused but requires 3-ones to be fused - and thus the thinking seems to be that that a twin socket is equivalent to a single socket with a 2-way adaptor in it, a triple socket is the same a single socket with a 3-way adaptor in it (hence triple sockets have an in-built 13A fuse).

   - Andy.