Recent content by Tech99

Do those 2008 & 2011 publications define that "2 phase 3 wire" as meaning the system we're talking about though? Couldn't they mean two phases plus neutral from a standard UK 240/415V 3-phase supply? And if that was supposed to mean a 240/480 3-wire supply, then what exactly has that "1...

The drawings without the third wire were to illustrate the direction and phase of the currents without that third wire, so that you can see how they don't change when that third wire is added. Yes. Ridiculously large text which can't even be read in full on a modest sized screen is stupid...

Sure they can. Many of the ones sold for computer cabling use have jacks for 8P8C modular, 6P6C modular and USB, with the jacks using line 1 up to whatever the maximum number of pins is needed. But you can also get units which work the same way and have 1/4-inch or 3½mm jacks for mono and/or...

Here's a progression of circuit arrangements which I hope might demonstrate the single-phase nature more clearly, starting with that odd (in power distribution terms) 3-wire arrangement in the new regs. Here's the system that those new regs apparently now want to call "1 phase 3 wire" with...

That applies whichever system we're talking about. Although it might not be common practice for power distribution, you could get the 240/480V UK system or the 120/240V American system from two entirely separate transformers; it's only a case of which way round the windings are connected as...

Just found this page which has PDFs of more recent forms: http://electrical.theiet.org/wiring-regulations/forms/index.cfm On all the forms listed there on the right from 1992 to the present the AC options are the same: 1-phase 2-wire 1-phase 3-wire 2-phase 3-wire 3-phase 3-wire...

I don't know if the IEE actually adopted it way back in the very early days, but I know for sure that it was in the 13th & 14th edition wiring regs.

I think it's just been more of a colloquialism. I've never bothered to follow the detail of the more recent regs, but I don't think it was mentioned as such specifically back in the 14th edition. I think the regs have always just called it single-phase 3-wire, in the same way as they...

So you're saying that by 2008 they didn't have a 1-phase 3-wire option? I wonder when that was dropped then. That seems an odd arrangement to list specifically, as it really amounts to nothing more than two single-phase 2-wire supplies which are sharing one conductor. That conductor will...

No, why? :? You can have 2 or 3 wire single phase. And did you regard the split phase arrangement as being single phase? There's no need to start getting silly. And now I think you're continuing to be silly by using the north pole as an example, because obviously at the moment you're...

It's been a while since I last saw one, but I would think there must still be a box or a list of options on an installation certificate to describe the supply type. Assuming that's so, if it still listed "1 phase, 3 wire" as an option up until now, that would settle that point. They may...

Seeing that prompts me into thinking that perhaps the only reason they've decided to call it "2 phase" is because (like the 90 and 120 examples) it shows two live connections. Two live wires doesn't mean two phase, but I do wonder if it's that simple, as wrong as it may be. As for the...

There is no compulsion to comply with BS7671. What's the point if you're just making a small extension to the wiring of a house which already has dozens of other sockets not fed by an RCD and dozens of other cables already not protected by RCD? A couple of extra sockets and a few more...

Any particular reasoning behind your selection of which diodes to omit?

Sorry, not having a copy I don't know what it's depicting. Could you explain what it's showing?