MK triple outlet with integral 13A fuse had a melt down

[YorkshireMidge]

We have an MK triple switched outlet in our kitchen on the ring main, not a spur. See Screwfix item 17315. Yesterday, the three appliances on it lost power. The socket has been there with the same three appliances on it for over a decade and I didn't initially realise this outlet plate has its own integral 13A fuse - and when I tried to extract it, the fuse holder came out in burnt pieces (the fuse is still in there!) so has obviously overheated. Everything else on the ring is fine.

I expected to be able to get an unfused triple outlet, but that doesn't seem to be the case. So I just wondered why triples I've found all seem to have a fuse but doubles do not. My assumption is it is because of the maximum load across the screw terminals and internals of a triple could be a third more than on a double, and it might not cope - yet the weak point in this case seems to have been the fuse holder itself.

As it stands, I intend to replace it with a double and a single, or two doubles.

 

[Mottie]

It’s not as if it’s lasted a few days or a week. If it’s lasted over a decade, why not just replace it with the same?

 

[YorkshireMidge]

It’s not as if it’s lasted a few days or a week. If it’s lasted over a decade, why not just replace it with the same?

Fair point. I haven't done the maths yet, but we have a dishwasher, washing machine and a waste disposal on it (!) - so it wouldn't surprise me if the total current through it was close to 13A at times. It's not much effort in this case to change the setup, so I just felt that is what should have been done in the first place.

 

[flameport]

Either replace it with another MK triple, or somewhat better if it really is on the ring would be 2x doubles with the dishwasher in one of them and the washing machine and waste disposal in the other.

If the dishwasher and washing machine were on simultaneously, there will have been periods where the current exceeded 13A.

 

[sparkwright]

You shouldn't really have those two large appliances plugged into it.

How many cables at the existing socket?
What size fuse or circuit breaker protects the circuit at the consumer unit?

 

[plugwash]

IIRC BS1363 requires unfused double sockets to be type tested at a total of 20A, 14A in one side and 6A in the other. IIRC Unfused triple and larger sockets are required to be tested at a total of 32A, I forgot the exact split, but I think it's something like two sockets with 13A each and a third socket with 6A.

On the other hand if the socket outlet is fused, then IIRC it's treated like a single socket for testing.

It seems the handful of manufacturers that actually make triple sockets (most don't), have all decided that fusing is an easier option than beefing up the internal connections to meet the requirements for unfused triple and larger sockets.

As for ways forward I see three possible options.

1. Replace like with like. It is an abuse of the socket, but the last one lasted 10 years, hopefully the next one will too.
2. Replace with Euro modules, this will let you keep the existing box and yet have three electrically independent sockets. But it's quite expensive and I'm not a huge fan of euro modules for mains as they are only held on the plate by clips.
3. Dig out the wall and replace with two seperate sockets.

Option 3 is IMO the best, though also the most work.

 

[Mottie]

Or replace with a 2+1 back box and have a single and a double socket outlet?

 

[sparkwright]

Could be a problem if the existing socket is a spur from a ring circuit.

 

[Mottie]

Could be a problem if the existing socket is a spur from a ring circuit.

Very first line in the OP's first post.

We have an MK triple switched outlet in our kitchen on the ring main, not a spur.

 

[plugwash]

Or replace with a 2+1 back box and have a single and a double socket outlet?

Yup, though that will require some digging out, as a single plus a double is larger than a triple.

 

[Mottie]

Yup, though that will require some digging out, as a single plus a double is larger than a triple.

Not as much digging out as two doubles.

 

[YorkshireMidge]

Thanks for the replies everyone - it's not much extra work to do this properly (I have one of those chain drilling templates for doing back boxes) so in the absence of anyone selling a beefed up unfused triple, my instinct is to put this right and do it how it should have been done in the first place.

A fused triple like this might have a place in some other room in the house where there is a cluster of lower current devices such as TV. DVD etc. but it just seemed to be the wrong place to use one.

 

[Mottie]

Here’s my triple/quad set up in the bedroom. TV, firestick, phone and in the summer, the fan.

 

[YorkshireMidge]

Handy gadget!

 

[Mottie]

Handy gadget!

For low powered stuff, yeah. I wouldn’t like to run a washing machine and dishwasher through it though!