Plug sockets

Tesla · 3 Feb 2007 at 01:00

You need to remember it's not just limited by the RCD or plug fuse but also the quality of the cabling in your house.

You cannot assume all of your cabling is 13A or greater stuff.

In our house someone has ran some of our office sockets on a 6A lighting cable so we had to downrate the RCD for that ring.

badgermonkey · 3 Feb 2007 at 01:01

I'm running a PC with a 600W psu, various PC peripherals, a TV, a clock/radio/CDplayer and a Nintendo Wii off of one socket.

Just get a surge protected extension or somethihng

Morba · 3 Feb 2007 at 01:04

jezsoup said:
Dude our knockin on 30, that reply is something id expect from someone whos just sprouted their first few pubes or something:/

rofl. i thought it was quite perfect for GD tbh. feel free to add me to your ignore :]

banja · 3 Feb 2007 at 01:13

Get outta my thread

This thread is about electricity, and pancakes.

Morba · 3 Feb 2007 at 01:20

banja said:
Get outta my thread

This thread is about electricity, and pancakes.

i did try, then jezsoup decided to throw his/her hat into the ring!

will have to get the wife to try that pancake trick in the morning for me when i wake up!!
gotta add some currants or raisins tho!

Kreeeee · 3 Feb 2007 at 07:41

Morba said:
stuff!

Now, now, no need to go OTT.

singist · 3 Feb 2007 at 09:23

I'm not a qualified sparky but here's a couple of things:

If your double socket is on a ring main you can draw up to 13 AMPS from each socket, though I would keep well below that.
If the sockets are on a spur, you can draw up to 13 AMPS total from the pair.

AMPS= Watts/Volts ......... so read all the labels to find out the wattage for your appliances that you intend to plug into each socket, add them together and divide by 240/250 to give the AMPS; depending on whether you have ring or spur, decide whether or not you are about to overload the socket.

Hope that that is both correct and of help; I'm sure that there are propper electricians who will put you/me right.

Dr.EM · 3 Feb 2007 at 12:11

Most the appliances your talking about are electronic and use relatively little. It's interesting to note though that just a kettle and toaster running from one socket will (theoretically at least) overload it.

The electronic devices also use varying amounts and will rarely use thier full specified power (ie, amplifier using less power on lower volumes). With the amplifier though note the power output and power input are not the same, they arn't that efficient usually (mine is 2x40w but uses 300w input).

I need to get a 10 way socket really, I've got a 4way and 6 way piggybacked at the moment

. They are half price at my work now so I shall pick one up (along with a tape lead mains cable for my digital camera, its currently got a euro plug which fits really loosely into an adapter)

banja · 3 Feb 2007 at 13:59

Seems like I'm unlikely going to go over 1kw, so even if the two plugs are running off one and therefore I only have 13 amps to play with, my calculator tells me that 1kw = 4.16 amps.

However, this is the windows calculator, so that calculation could be way off

Street · 3 Feb 2007 at 15:40

Pfft.. Just plug them all in.. If it goes boom then you know it won't work!

Dandle · 3 Feb 2007 at 17:32

The current you can draw from any socket will depend on the fuse/rcd used on that ring(normally 30A) and on what other appliances are supplied on that ring main. If its a spur then there is a limit to the amount of plug sockets of a spur, although if the wiring is good and not bodged you will still be able to draw enough on the spur to blow the fuse/rcd way before the wiring has any problems. With what the guy in the OP is using there will be no problem at all as its not a very heavy load comapered to say running heaters or kettles on it.

A 30A fuse/rcd will blow when you are drawing 7.2kw on it and thats a fair amount of power.

iBot · 3 Feb 2007 at 17:34

I've ran a 8 pc lan off 2 plug sockets.

It's fine, just make sure your run fairly recent insulated extension leads.

Trigger · 3 Feb 2007 at 18:30

Dandle said:
The current you can draw from any socket will depend on the fuse/rcd used on that ring(normally 30A) and on what other appliances are supplied on that ring main. If its a spur then there is a limit to the amount of plug sockets of a spur, although if the wiring is good and not bodged you will still be able to draw enough on the spur to blow the fuse/rcd way before the wiring has any problems. With what the guy in the OP is using there will be no problem at all as its not a very heavy load comapered to say running heaters or kettles on it.

A 30A fuse/rcd will blow when you are drawing 7.2kw on it and thats a fair amount of power.

The fuse in the plug will be the first thing to go- what would be the point in having them otherwise? The MCB protects the circuit as a whole- not a single socket. Also, people seem to be confused between RCDs and MCBs- you will very rarely get an RCD protecting just one circuit and even if it is, it will never protect it directly as there will always be an MCB between it and the circuit. RCDs detect an imbalance in current between the live and neutral (A leakage to earth basically) and it's very rare that a current overload will trip it as thats what the MCBs are for.

Everyone using a ton of four gang extention leads on one double socket are asking for trouble- the electrical system was not designed to take them and even if they are used, connecting them in series is a very bad idea indeed. If you need more sockets, add a couple of spurs in (Not off the same socket mind)- it's much safer

banja · 3 Feb 2007 at 19:12

Trigger said:
Everyone using a ton of four gang extention leads on one double socket are asking for trouble- the electrical system was not designed to take them and even if they are used, connecting them in series is a very bad idea indeed. If you need more sockets, add a couple of spurs in (Not off the same socket mind)- it's much safer

Okay, so now you're making me think again. Are you suggesting it isn't safe to run two four way extensions off two wall sockets, for a combined total wattage of <1kw?

And what in the heck is a spur?

Dandle · 3 Feb 2007 at 19:31

Trigger said:
The fuse in the plug will be the first thing to go- what would be the point in having them otherwise? The MCB protects the circuit as a whole- not a single socket. Also, people seem to be confused between RCDs and MCBs- you will very rarely get an RCD protecting just one circuit and even if it is, it will never protect it directly as there will always be an MCB between it and the circuit. RCDs detect an imbalance in current between the live and neutral (A leakage to earth basically) and it's very rare that a current overload will trip it as thats what the MCBs are for.

Everyone using a ton of four gang extention leads on one double socket are asking for trouble- the electrical system was not designed to take them and even if they are used, connecting them in series is a very bad idea indeed. If you need more sockets, add a couple of spurs in (Not off the same socket mind)- it's much safer

Your right that the fuse in a plug is the first thing to go. In any extension lead the fuse should not be above 13a anyway so you can have as many of them as you want but if you exceed 13a then the first one plugged into a main socket should blow. All I was pointing out was that the ring main can supply more current than any extension lead is going to take no matter what is plugged into it. It is a bad idea to have lots of extension leads of one plug point but in reality it wont be a probelm for the OP as there aren't that many plug points needed and none of them are really high current devices anyway.

Dandle · 3 Feb 2007 at 19:38

banja said:
And what in the heck is a spur?

A ring main has two supplies coming out of the fuse box with one going one way around the ring main and the other the other way until they meet in the middle. Most of the plugs in your house will be wired up this way and its called a ring because if you trace the wiring around from the fuse box you will come back to the fuse box at the other end. A spur is like an extenxion lead being plugged in(although it is hard wired) which is one piece of wire with plugs on it but at the last plug it ends and doenst return anywhere. Sometimes people will fit spurs if they are adding just one plug to a wall if breaking into the ring main is too much work.

dalex · 3 Feb 2007 at 19:41

a 3kw heater is about max for one socket as the cable becomes hot, indicating it is close to the fusible load ,as the fuse is there to protect the cable
dave

Dr.EM · 3 Feb 2007 at 19:47

Also note how most high power devices have shorter cables. This is to stop you being able to coil them, which makes them more inductive, which in turn makes them more resistant with AC and consequently makes them heat up excessively. You'll often see the warning on the coil/drum extension leads along the lines of "fully uncoil before use" or "uncoil if load exceeds 2Kw" etc.