Mains socket & extension cable question

[FishPolice]

How do you determine the amount of plugs you can safely attach to a domestic (UK) electrical socket?

I had always been under the (idiotic?) impression that it depended soley upon amps. For example, say I have an extension cable with 4 sockets and that extension cable is rated for 13 amps, I always assumed that I would be fine as long as I didn't plug in anything that used up more than 13 amps in total -ie. 4 x 3 amp plugs would be fine as that would be 12 amps total, but 1 x 13 amp plug + 3 x 5 amp plugs could be a problem as that would equal 28 amps.

I've been googling for a simple idiot guide for this question and although I can't find the simple information I need, I am getting the impression that maximum load is actually to do with the total wattage demanded by all the appliances.

Thing is, I'm still confused. If I went and ordered something like:
Belkin 8-Socket SurgeMaster with Telephone & Network Protection (F9M824UK2M) (UP-009-BE)
then surely I would be limited to what I could attach to it because of the rating of the mains socket itself which is rated at something like 13 amps @ 240v?

Also where does Joules come into the equation? -that's not the same as Wattage is it?

Can anyone point me in the direction of a guide or give me some simple straight-talking answers. Many thanks

ps. I do rabbit on when I ask a question don't I?

 

[squiffy]

Don't worry about it, unless you're plugging in several electric heaters into one multi-way block. I've had 7 poweramps, two PC's and one display into one 12 way and the fuse didn't trip.

 

[FishPolice]

ok so with a double socket could I get away with this lot?

one socket:

• PSU
• TFT
• speaker amp
• router
• printer

other socket:

• bedside lamp
• alarm clock
• telephone (recharging base)
• bedside lamp
• alarm clock
• security light

Reason I'm so cautious is when I was a poor student I had an extension cable which I was running an old 3-bar electrical fire off. That particular extension cable was the old cheap type which has no internal fuse but I'd assumed I was ok cos there was a 13amp fuse in the plug at the other end. Anyway, one day there was the smell of burning and this cable was now the colour of medium cooked toast. I had assumed the fuse in the plug would have gone before that happened so now I'm a big scaredy cat cos I don't want to to kill my family through my own stupidity.