I have a mains plug that lets me wire in up to four appliances. It's a much neater solution that a trailing socket. Naturally, I'm limited to
13A in total. I assume it's not likely that a hi-fi amp, cd player, SCART switch box, and DVD player will get near that?I mean, I'd certainly have connected all four to a trailing socket, for better or for worse. ;)
Not in a million years.
However, it does mean that each individual device, and its associated cable, is protected through a 13A fuse (unless the plug contains 4 fuses, which is unlikely). This is not ideal, since it is a potential fire risk.
Not likely, no.
Owain
I see. You're saying that each individual device has (tending to) 13A headroom instead of the e.g. 3A that it should have. Hmm. That's ruined that idea. I thought it was too good to be true.
Nowhere near. Personally, I would replace the fuse with a 3A fuse, which is easily enough to cover all the audio visual equipment in one house, unless there are powerful amplifiers involved (i.e. hundreds of watts rms). Use 5A is there is a TV involved, particularly a CRT one.
I presume this device is intended for the purpose stated, you're not just wiring up four devices to a standard plug?
Christian.
If all the appliances mentioned are fairly modern and have 0.75 mm^2 flexes then there's no need to worry at all, even if you don't change the fuse to (say) 5 A.
However, unless it's a _Very_ unusual hifi - >200W RMS - all of those together will be quite happy on a 3A fuse. If it's a normal sort of ~50W RMS amp, all should be fine on a 1A fuse.
It is intended for such use. I'm not /that/ clueless!
Is there any way to work this stuff out accurately? A cursory glance on the back of the devices didn't reveal any power ratings.
Why should that be likely? AIUI, each plug should contain the appropriate fuse. Four off plugs ,each at three amps, would be adequately serviced by a thirteen Amp fuse in the four-to-one plug/socket device. AUIU, the fuse in the plug, 3A, doesn't 'know' how much 'headroom' it 'has' in the 13A socket. Why do you think it's different?
Every appliance sold has a plate somewhere giving the consumption in watts. To make calculations easy, make every 250 watts 1 amp. So a product with a consumption of 1000 watts takes 4 amps. Two of those would take 8 amps. Etc.
Almost all audio visual equipment takes only a paltry amount of power when in use. The only exceptions are ASBO style amplifiers (and only when turned up) and CRT televisions, especially during warm up. Huge LCD/Plasma televisions can take a little bit of power, too.
However, in reality, you can run the whole lot off a single 3A fuse.
Christian.
Medium sized CRT TV/monitors use about the same power as a similar sized LCD generally.
The message from Ian Stirling contains these words:
This, from Cornell Uni seems to contradict that...
is 4 wires in 1 plug possible? I've never got more than 2 in under the cordgrip. Maybe I should change over to speaker wire :)
NT
Odd. On checking.
The two monitors I have have significantly overrated power supplies. (as in double their actual usage).
I was assuming they really used that. I guess they overrate it to increase life.
Nope. Little bit of boucing around, but it doesn't overshoot the startup current.
There may be a signifcantly higher switch-on current, as the backlight gets going.
Fair enough - didn't know what sort of meter you were using or the response time.
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