Mains socket converters

[battered]

So cut the crap, give us the numbers.
AIUI:
If on a single spur 2.5 T&E, it's 20A total, regardless of how many sockets are on the circuit.
If on a ring of 2 x 2.5 T&E then 30A total, spread across X sockets.
For any individual double socket I thought it was 2 x 13A so 26A, but if as above then a double will only handle 13A +6A.
So the proper answer is what?

(Says the man who saw a 2kW kettle plugged in on one half of a double and another on the other side, along with a few other bits and bobs via a 4 way, until he unplugged it and spread the load across the ring main)

[Sheepshanks]

elster said:

MX51ROD said:

finlo said:

Even on a twin socket it's a max of 13A for the two outlets not each.

Wrong,it depends on the protection,a 32a ring circuit could support 2 3kw appliances,in one twin socket ,but not a 3 kw appliance in every socket on the circuit,it is all to do with the protective device ,be it a fuse or a circuit breaker.

Not so, it depends on the outlet fitted.

Most sockets are rated at 13A for a double socket, however some cheaper sockets have been known to not even match that I know a few years ago LAP were found lacking in independent testing.

The daft thing is, unless it's changed recently, you can wire a double socket as a spur off a ring main using a single 2.5mm cable. So the circuit breaker on the ring is rated higher than the cable. It's just assumed that people won't fully load the sockets.

[RizzoTheRat]

Sheepshanks said:

The thread got a bit diverted but to answer that question specifically, if the kettle and toaster combined exceed 3000watts then don't put them on at the same time as you'll be over 13A.

Well the kettle alone is 3KW, so 12.5 amps, whcih was what got me thinking. I can make a cuppa in half the time I used to be able to with the old kettle but better not have any toast with it

There does seem to be some conflicting info out there, that data sheet linked does indeed say that particular twin socket is rated at 13A per socket outlet, but then again Iv'e not looked at the data sheets for other sockets so that doesn't mean they all are.

Sheepshanks said:

The daft thing is, unless it's changed recently, you can wire a double socket as a spur off a ring main using a single 2.5mm cable. So the circuit breaker on the ring is rated higher than the cable. It's just assumed that people won't fully load the sockets.

My circuit breaker is 32A, but it's a new consumer unit, the old one had 4 fuses for the whole house. I'm guessing the guy who fitted the new one didn't work out the entire house's wiring before fitting it.

Edited by RizzoTheRat on Saturday 14th January 22:08

[Alucidnation]

finlo said:

Alucidnation said:

No need as it has already been mentioned, but it's been a bit lost in amongst the drivel.

As a spark myself i'd like to think I was offering sound/accurate advice.

[battered]

RizzoTheRat said:

My circuit breaker is 32A, but it's a new consumer unit, the old one had 4 fuses for the whole house. I'm guessing the guy who fitted the new one didn't work out the entire house's wiring before fitting it.

Edited by RizzoTheRat on Saturday 14th January 22:08

Not many kettles are the full 3kW any more. 2.2 is about the max these days.

Household wiring is based on a lot of redundancy and the assumption athat nobody plus a 3kW fan heater in every socket. Most stuff is radios and table lamps that are worth f* all loading.

[Sheepshanks]

RizzoTheRat said:

Well the kettle alone is 3KW, so 12.5 amps, whcih was what got me thinking. I can make a cuppa in half the time I used to be able to with the old kettle but better not have any toast with it

In a double socket it'll be absolutely fine to have both on at the same time. If you use the triple with its built-in fuse then it may blow the fuse, although you might get away with it due to the short time the appliances will be on. Not recommended though.

I bet a lot of people run a washing machine and a dishwasher or tumble dryer plugged into the same double socket and don't even notice that the socket gets warm.

RizzoTheRat said:

My circuit breaker is 32A, but it's a new consumer unit, the old one had 4 fuses for the whole house. I'm guessing the guy who fitted the new one didn't work out the entire house's wiring before fitting it.

32A is correct.

[Paul Drawmer]

Sheepshanks said:

Paul Drawmer said:

Did you look at the the link I posted? Scroll down to the second page , on the left side.

I'm pretty sure that's the one that MK's engineers weren't happy about.

ETA: This is the post I was thinking of: http://www.diynot.com/diy/threads/double-sockets-m...

Thank you for posting that. I apologise for posting misleading information, I am guilty of believing what was written on an internet site(!)

[MX51ROD]

battered said:

Household wiring is based on a lot of redundancy and the assumption athat nobody plus a 3kW fan heater in every socket. Most stuff is radios and table lamps that are worth f* all loading.

Its called diversity , BS7671 takes this into consideration , hence a 32a mcb the largest for a domestic circuit where portable appliances are to be connected will trip if more than 8kw( a loose approximation of current/power , not addressing power factor ) is drawn , this also considers the use of a “spur” circuit , in practice I would never wire a single cable to an additional socket , I would extend the ring , or wire via an FCU .The problem is the main failing of BS7671 is the stupidity of the end user of the installation
Gas and electricity are the 2 most things to ask advice for on a forum .

[Djtemeka]

pah! I have an oven, hob, washing machine AND dishwasher hooked up to the same circuit. dodgy kitchen installers!

[RizzoTheRat]

So being the sad geek that I am I've just checked my toaster and it claims to be 1500-1800W, so kettle and toaster together are up to 4.8KW, ie 20A, which from comments above seems to be a test condition that a double socket should be able to cope with, but more than it should have on it.

I'd guess a large number of households run a toaster and kettle on the same sockets without a problem, but it's surprised me slightly how easy it is to overload a socket.

Dunno about the washing machine but the dishwasher claims to only be 1KW so the socket they're both plugged in to is a lighter load, but if I assume the washing machine is 1KW as well, then if turn on the food processor at the same time I'm pushing 32A on the ring main already

Edited by RizzoTheRat on Sunday 15th January 11:10

[jason61c]

Djtemeka said:

pah! I have an oven, hob, washing machine AND dishwasher hooked up to the same circuit. dodgy kitchen installers!

I think a kitchen should be on its own circuit. Oven on its own?

[hairyben]

RizzoTheRat said:

So being the sad geek that I am I've just checked my toaster and it claims to be 1500-1800W, so kettle and toaster together are up to 4.8KW, ie 20A, which from comments above seems to be a test condition that a double socket should be able to cope with, but more than it should have on it.

I'd guess a large number of households run a toaster and kettle on the same sockets without a problem, but it's surprised me slightly how easy it is to overload a socket.

Dunno about the washing machine but the dishwasher claims to only be 1KW so the socket they're both plugged in to is a lighter load.

The socket is rated at 13amp, which is the total rated load. Anything else is irelevent.

In practice its only sustained high loads, eg washer & dryer, that will burn one out, 2 mins to boil a kettle ought be fine. Converters are okay for what they are but they're a bit cheap, and it tends to be the cheap'n'nasty stuff that fails especially in kitchens with higher loads, stuff like LAP and wickes. Converters are okay for a bedroom with a lamp and a phone charger but chopping in a couple of boxes for proper doubles would be the ideal for kichen use.

3 way sockets have a fuse as technically they're not recognised by regs so cover themselves by fusing the item down. Them and converters are all permissable to fit whereever you like, avoiding them for "heavy use" is purely best practice.

[battered]

hairyben said:

RizzoTheRat said:

So being the sad geek that I am I've just checked my toaster and it claims to be 1500-1800W, so kettle and toaster together are up to 4.8KW, ie 20A, which from comments above seems to be a test condition that a double socket should be able to cope with, but more than it should have on it.

I'd guess a large number of households run a toaster and kettle on the same sockets without a problem, but it's surprised me slightly how easy it is to overload a socket.

Dunno about the washing machine but the dishwasher claims to only be 1KW so the socket they're both plugged in to is a lighter load.

The socket is rated at 13amp, which is the total rated load. Anything else is irelevent.

In practice its only sustained high loads, eg washer & dryer, that will burn one out, 2 mins to boil a kettle ought be fine. Converters are okay for what they are but they're a bit cheap, and it tends to be the cheap'n'nasty stuff that fails especially in kitchens with higher loads, stuff like LAP and wickes. Converters are okay for a bedroom with a lamp and a phone charger but chopping in a couple of boxes for proper doubles would be the ideal for kichen use.

3 way sockets have a fuse as technically they're not recognised by regs so cover themselves by fusing the item down. Them and converters are all permissable to fit whereever you like, avoiding them for "heavy use" is purely best practice.

It's not 13A across the whole double circuit, as someone posted up on the previous page it's a total of 20A across the 2 to meet the BS. Apparently they are tested for so many hours at 14A +6A and checked for temperature rise. So your kettle and toaster will be OK in a double even if you have a big family and an extended breakfast, because the 20A is just at the limit of capability for a continuous load and as pointed out above nobody has the kettle or the toaster running for hours on end, still less both at once without a break for hours.

As someone said just a bit earlier, the biggest problem is the stupidity of the end user. A cheap 4 way in a teenager's bedroom may only have a table lamp and a radio most of the time, but it only takes one idiot to plug in a fan heater, a kettle and a hairdryer on the same socket for things to go pearshaped.

Speaking of stupidity, my garage is wired on a single 5A breaker covering lights and a double socket. When I moved in I needed to weld a leg on a workbench. Plugged the welder in, standard issue 140A stick welder that runs off a 13A plug, got it all set up, hit the power switch.
MCB said "You can f* off"
I said "Oh bks" and ended up running an extension cable from the house, which has a proper 30A ring main.
Bloody cheapskate builders. How much more would it have cost to run a proper 2.5 T&E to the garage socket instead of running it on a 5A spur and saying "sod it, most people only run a hoover in there to clean the car out, that'll do."?

[bigdom]

jason61c said:

Djtemeka said:

pah! I have an oven, hob, washing machine AND dishwasher hooked up to the same circuit. dodgy kitchen installers!

I think a kitchen should be on its own circuit. Oven on its own?

We put an extension in last year, the kitchen ended up on 5 circuits. 1 for each of the 2 ovens, 1 for induction hob, 1 standard ring, and fridge on it's own.

When we bought the house, it had the crappy wire fused box, to future proof it when it was changed I added the largest consumer box possible. As we've gone through the house, it's been rewired and split down.

Personally I don't like extension sockets/leads, maybe overkill for some, although, there's 14 doubles in my lounge, 6 doubles being behind the TV alone, so everything gets its own socket.