Something I don't understand - 2.5mm Cable Rating

[pbar]

Not a lot, how many times have we seen the washing machine and tumble drier plugged into the same double socket?
Saying that, those 2 way adaptors you can buy for about 99p don't have a fuse in either.
Some bedtime reading on the origin of the BS1361 plug and socket outlet

Some of those adapters do have fuses inside, I've seen a couple.
They should all be fused I think, especially the 3 and 4 way one's.

 

[Adam_151]

But what is to stop someone (unknowingly or otherwise) plugging in two high powered appliances and causing a potentially dangerous situation. As I understand the regs don't require an FCU for this spur either.

What's to stop somone doing this on any socket?

Because 'any socket' won't always be a spur.
On a ring, the load is spread over 2 cables.

It may well be spread over two cables, but it is only 'spread over' one sockets terminals

The answer is of course that its not a big enough problem to worry about in reality, you'd have to draw 20A+ for quite a long duration (on MK kit more than a day, on others probably less) to start causing a problem, You're unlikely to plug two heaters next to each other, You could have a rumble drier and something else, but they only run for 90mins or so, and you aren't going to have a heater next to one, you might have a washer (which I don't think runs its heater for that long, perhaps 30mins), ditto dishy washer, kettle and toaster run for about 5 mins.


So while you should avoid having them both on a double socket, it might be more worthwhile worrying about rubbishy connections in the moulded plug on the dryier, or as bernard suggests, poor fuse contact, or even weakened socket outlet bits (a much bigger problem in the US than here I understand, with plugs sometimes falling out of worn sockets, but if you've ever seen the weedy things they let pass for 15A plugs....)

Design of the BS1363 isn't amazingly great though, anyone who has had hold of a 15A BS546 will testify how British it feels

 

[pbar]

But what is to stop someone (unknowingly or otherwise) plugging in two high powered appliances and causing a potentially dangerous situation. As I understand the regs don't require an FCU for this spur either.

What's to stop somone doing this on any socket?

Because 'any socket' won't always be a spur.
On a ring, the load is spread over 2 cables.

It may well be spread over two cables, but it is only 'spread over' one sockets terminals

The answer is of course that its not a big enough problem to worry about in reality, you'd have to draw 20A+ for quite a long duration (on MK kit more than a day, on others probably less) to start causing a problem, You're unlikely to plug two heaters next to each other, You could have a rumble drier and something else, but they only run for 90mins or so, and you aren't going to have a heater next to one, you might have a washer (which I don't think runs its heater for that long, perhaps 30mins), ditto dishy washer, kettle and toaster run for about 5 mins.


So while you should avoid having them both on a double socket, it might be more worthwhile worrying about rubbishy connections in the moulded plug on the dryier, or as bernard suggests, poor fuse contact, or even weakened socket outlet bits (a much bigger problem in the US than here I understand, with plugs sometimes falling out of worn sockets, but if you've ever seen the weedy things they let pass for 15A plugs....)

Design of the BS1363 isn't amazingly great though, anyone who has had hold of a 15A BS546 will testify how British it feels

Yes, it's spread over one socket terminal, my original point though being that of the cable however, and the possibility of too much power running through a single cable from a spurred double socket. Can't really believe that a double socket spur is allowed and is legal without having an FCU. Or double sockets with an FCU built in should be available for this purpose perhaps (or maybe they are). But yes, I take your points that maybe it is an unlikely danger. It's just that there seems far more absurd regs for far lesser issues.

 

[FatGit]

But what is to stop someone (unknowingly or otherwise) plugging in two high powered appliances and causing a potentially dangerous situation. As I understand the regs don't require an FCU for this spur either.

What's to stop somone doing this on any socket?

Because 'any socket' won't always be a spur.
On a ring, the load is spread over 2 cables.

Not Equally. The current will take the path of least resistance (i.e. the shortest leg). Unless, of course, the socket outlet is in the exact middle of the ring.

 

[pbar]

But what is to stop someone (unknowingly or otherwise) plugging in two high powered appliances and causing a potentially dangerous situation. As I understand the regs don't require an FCU for this spur either.

What's to stop somone doing this on any socket?

Because 'any socket' won't always be a spur.
On a ring, the load is spread over 2 cables.

Not Equally. The current will take the path of least resistance (i.e. the shortest leg). Unless, of course, the socket outlet is in the exact middle of the ring.

Thanks for your point. Although I never said it was equal, just that it would be spread over 2 cables

 

[ColJack]

Not Equally. The current will take the path of least resistance (i.e. the shortest leg). Unless, of course, the socket outlet is in the exact middle of the ring.

it won't ALL take the path of least resistance..

it will be split down each leg according to the resistance of said legs..
without going into exact figures...

"a ring is 30M in length.. a socket is 10M along one of the legs... this means it is 20M along the other leg.. so 1/3 of the current will go down the 20M leg, and 2/3 of the current will go down the 10M leg.. "