Safe electrical Limits


I am in the UK, (so 240v power supply).

I have gradually built my gaming system up and up, and as you know, when adding monitors, sound, game controllers, there always seem to be yet another power supply to go with them.
I'm sure many of you will recognise this situation.

Items requiring power socket are

PC with 700W PSU;
3 x 22inch monitors @ 25W each;
G27 wheel
5.1 surround speaker system
stereo powered speakers (added these to make it up to 7.1)
1 x Mini Amp (12v DC adaptor for each ) for SimVibe setup.

Everything works perfectly well but I'm about to add two more mini-Amps and there will then be about 10 plugs in total. I have them going into fused extensions, and then into two mains outlets (on the same circuit).

I don't think these are horrendous numbers, but I would appreciate some advice about the best way to protect my system from electrical fire. What devices should I be inserting for added protection? Is it enough to have a circuit breaker at the main sockets?
(I am more concerned about protecting my house than protecting the individual devices).

Thanks for any help,

Graham Laing

Retired Staff
You'll be fine.

Your heavy hitter there is your PSU. It may be 700 watts, but in reality, depending on your system, during gaming it maybe pulling in the region of 400 to 600 watts. My system pulls around 650 watts when benchmarking dual video cards, and the CPU flat out, and 400 - 500 watts when gaming. It idles @ 155w with 2 monitors. I have a watt meter connected to my PC. (Power Supply Spec 750W @ 90% efficiency)

Let's assume that it would be working flat out at 700 watts, but also assume that it's not particularly efficient, with a Bronze efficiency of 80%. So assume 700/8 x 10 = 875 watts is actually being taken from the mains. Plus 3 x 25 watt monitors = 75W + 875W = 950 Watts

A bit of ohms law - Current (Amps) = Watts/Volts = 950/240 = 3.95 amps.

Standard UK socket = 13 amps MAX.

You are well within the amps limits, and the other stuff you have is unlikely to add a substantial amount more. Even if you doubled it, you will be fine.

The load is spread across 2 outlets, but is on the same ring main, but that's ok. A modern house will have circuit breaker protection, and your plugs will have fuses.

You can use surge protection if you wish, for peace of mind if it worries you. :)
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Yes I have plenty of fuses along the way, and circuit breaking all works fine. That is very helpful thanks Graham. I did some of the maths and I thought it seemed ok, but thought it was worth asking anyway :)

I shall continue setting up my Simvibe, now less worried about adding a couple more mini amps along the way!