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On 31/10/17 23:29, Peter Humphrey wrote: |
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> On Tue, 31 Oct 2017 17:33:53 +0000 |
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> Wols Lists <antlists@××××××××××××.uk> wrote: |
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> |
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>> In the UK at least also, we have ring mains. These are rated at 30 Amps, |
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>> from which you can take a 13 Amp feed from any socket. Once you start |
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>> taking power over multiple leads the wiring has more resistance, plugs |
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>> introduce resistance, etc, and the voltage can drop rapidly. |
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> |
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> I've never seen that, nor heard of it. It sounds like a major fire risk too, |
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> which the wiring regs would never countenance. |
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Sorry, no, I meant plugging one extension lead into another ... exactly |
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what you are NOT supposed to do. |
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> |
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>> (It is mandatory, according to code, if you hard-wire a feed off a ring |
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>> you must separate it with a 16 Amp fuse.) |
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> |
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> I don't recognise that either. It sounds like a special case to me. And |
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> where do I buy a 16A fuse? |
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> |
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Well, I've got several scattered over my house ... and my father-in-law |
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has at least one in his fuse box! |
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You would have thought it was easy to take a spur off of a socket that's |
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part of a ring main, but believe me, as an amateur sparky it's NOT! They |
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sell special points - often with a switch - to take a feed off a ring, |
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and they all have a - mandatory - 16Amp fuse. Or they might take a |
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standard 13Amp fuse. |
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My father-in-law has a spur coming off his fuse box, and that has a |
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16Amp fuse or circuit breaker, rather than the standard 30Amp. I did a |
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bit of wiring for him ages ago, and when I saw it, my immediate reaction |
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was "what the heck's that!" and I refused to touch it until I'd worked |
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out what was going on - very sensible advice with electric! |
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>> I've never seen one, but I would have thought a motor/generator pair |
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>> with a hefty flywheel would provide very good surge/spike/whatever |
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>> protection, and provide nice clean power. Plus, it would be unlikely to |
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>> burn out if you had to provide protection from several big consecutive |
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>> shocks, like a lightning strike. |
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> |
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> Just think of the noise though, and the expense. |
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> |
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Why should it be noisy, or expensive? Okay, you're turning electrical |
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energy into kinetic and back again, but a computer draws typically 2Amps |
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max. A box like that to provide clean power shouldn't be too bad. |
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(Actually, using something like that as the PSU to step down to 12V or |
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5V might be a good idea in areas of dirty power ... :-) |
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Cheers, |
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Wol |
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