I have a twin power socket behind my desk in my bedroom. Both sockets are connected to a power strip extension. Does anyone know what the maximum number of appliances/extension sockets I can safely use? I need to power:

- desktop computer
- desktop speakers (5.1)
- desktop monitor
- inkjet printer (for B&W text)
- TV
- indoor TV antenna (powered)
- PS3
- router
(the above is what I have connected to power strips, each one with four sockets)
- photo printer
- IR receiver box
- WD TV Live
- NAS

That would bring the total to 12 devices. I can get my hands on a 6-socket extension. Would it be safe to have all the items connected?

The question is not really how many appliances are in use, but rather what the maximum wattage they could consume would be (and if you would use them all at the same time). And not just the demand in your room, but on the ring that supplies your room in total (generally the entire floor in an average house).

The appliances you've mentioned don't sound too excessive, but if you replaced them with a kettle, microwave and heater, then demand could be more of an issue, especially when you consider other appliances on the same ring. Generally electronic isn't too much of a worry, but electric is.

That's my concern but wasn't aware about the ring circuitry. IMO my room is the heaviest in consumption by a good margin. How do I work out draw? Would it just be I=P/V?

Maximum power that can be drawn is Volts x Amps so in the case of an extension with a 13Amp fuse in it on UK 240Volt mains just over 3kWatts.

Each electrical appliance should have its power consumption marked either on the back where the mains cable is or in the technical specification in the manual. Add up all the power requirements of the gear you've listed and I'd be surprised if the total even reaches 1kWatt. You should be fine, although if both your extensions are in the same place I would consider distributing the load equally between the two.

Also the UK ring main is rated overall at 30Amps (because it's configured in a ring) so that means that the maximum total draw from all the devices on the ring is just over 7kWatts.

I have a lot of devices plugged in to my bedroom socket but literally everything is low power usage apart from my iMacs. Loads of lights but only 3W each, so it still does not hit 500 W if everything is plugged in and on.

Gotta love the ring main. AFAIK it's all radial/spur in Oz. Well at least they use 220-240V.

Surprising how some devices have no info at all. The largest consumers are the desktop pc (I put in a 300W supply) and the PS3 (380W). The remainder all fit into the remaining use and the total barely breaks 1kW.

What about the TV? Some big screens are really energy hungry. 200W+ for some plasmas.

Ring main is almost unique to the UK. In France they consider our electrics to be positively dangerous!

As it happens, my parents are facing a €1000 bill because of an incompetent French electrician. He wired the distribution board incorrectly, and the entire thing has now burned out after about 10 years of intermittent problems.

I have a 20" LCD TV. It consumes around 65W.

My 32" LCD consumes around 90W at peak. Though some older plasma's are energy hungry. My iMacs are 150W each at peak but I have not monitored them recently.

You can buy LCD display plugs that you plug in between the plug and the wall socket. Cost around £8 from Maplin, will measure current and wattage going through it and will let you know the difference between what the appliances use normally and under load, it's what Custom PC used for the group tests, I used one for testing battery UPSs; it's very useful, and is the reason I'll never buy a cheap PSU again (massive false economy).

Do you have a link?

I use this

Morning

Wrong thread?