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| Emergency stop switch for study/lab (UK wiring question) |
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| Monkeh:
--- Quote from: Docara on December 04, 2019, 07:15:32 pm ---If this was an extension lead screwed to the wall what's the difference? If this was in flex feeding sockets via a stuffing in the end of some dado trunking or any trunking come to that, what's the difference? --- End quote --- I don't know how this is defined in the regulations (I am neither a sparky nor a lawyer, but I know my way around the bits which spark nonetheless), but an extension lead is designed and supplied to operate as a portable, self-contained item - wall fixing is for convenience. A surface mount box, or some trunking, or any other item designed to be fixed to a surface for its entire operational life, is, well, a fixed item, and if you're assembling the wiring system from scratch I can't see any reason to exempt it from appropriate standards - I admit BS7671 may not be that standard if it's attached to a desk not the wall. --- Quote ---I don't have my (17th Ed Amend 3) regs to hand but I can't think of anywhere where it states you can't. You don't test extensions cables do you. They rely on the protection offered by upstream devices RCD's, MCB, Fuses as applicable. What if you have a flush FCU, back feeding a boiler with a cable buried in a wall is the boiler part of the fixed installation - No, it' is an accessory. You would disconnect it when carrying out out an Installation Resistance Test! How about a 240V thermostat with cables buried in the wall - again we don't test. There are many instances like these which are not part of the fixed installation. --- End quote --- I don't see how a boiler, its thermostat, pump, zone valve, programmer, and all the cabling involved are not part of a fixed electrical installation! There may be limitations on the ability to test (but not inspect!) them, but they're absolutely part of the installation. Or are you suggesting all my central heating wiring can ignore BS7671, cable zoning, current rating calculations, and so forth, because it's all an accessory? Of course that wiring should be inspected and tested as any other! Is a socket with a built in USB charger exempt from being part of the fixed installation and compliance with BS1363 by virtue of not being able to take a 500V IR test? As far as extension leads, well, in commercial environments someone does test them, as well as appliances, and as an electrician if working domestically you should at least be performing a visual inspection of customers equipment you come into contact with. As far as the term competent person, I agree, dreadful term. There's a huge difference between actual competency (which I can claim in technical knowledge, frankly, and at least some of the practical, I've yet to do SWA, probably never do MI, and so forth) and qualifications, which is what they're actually after. Unfortunately qualifications don't prove competency adequately in practice, and competency does not imply qualification.. --- Quote ---Wiring Regulations and the Law, I don't fully understand this, but basically it goes something like this. The wiring regs are not law but they are incorporated into the building regulations and I think the Health and Safety legislation which ARE law therefore they are a legal requirement. - Something like that. --- End quote --- Now, again, I may not be up on the law because they make it impractical to be so, but as I understand it the law effectively only requires that installations be designed and installed in a safe manner - BS7671 is simply the accepted way to achieve this, and if you fully and correctly comply with it (and other actual laws - EAWR..) you have an extremely strong defense. You can deviate from BS7671 or even ignore it entirely, but then you have to defend your position - good luck if you've got more than some minor deviations to cover. The courts will crush you even if you did nothing wrong, just because you're an easy target. E: And oh boy, are we well and truly off on a tangent here. For the benefit of the OP I'll repeat my advice along with generally good advice: Use an FCU (either as a spur or inside the ring, I don't mind) to protect a moderate number of additional sockets for your purposes, with no messing around with figure of eights and cooker switches and other insanity, OR eat the cost and have a good electrician around to sort things out to his, your, and the law's satisfaction. |
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