Traineeboy
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- Apr 22, 2020
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I’m aware of that but does that mean the Electricians guide to building regs not count ? That isn't a Sarcastic question I’m just wanting to clarify.
we design, test and install to BS 7671 18th editionI’m aware of that but does that mean the Electricians guide to building regs not count ? That isn't a Sarcastic question I’m just wanting to clarify.
it's a guideline figure, ie for soft ground likley to be dug with a spade, 500 / 600mm is a reasonable depth, but if you were laying cable under a solid concrete driveway, what's the chance of cutting through cable with a spade? There are different depths for high ways and ploughed fields, where digging is more likely.I’m aware of that but does that mean the Electricians guide to building regs not count ? That isn't a Sarcastic question I’m just wanting to clarify.
I don't see that you need to do all that stuff , run a 3 core SWA , earth your glands in the usual way . You say its a TN-S supply I think.I would then not earth nut at the new building end but install an earth rod. Would this be the correct thing to do ?
It was given to me in feet i do normally use Meters but yes I guess I am a little older than a 19 year old apprentice. TT wise am I right in thinking even if you use the suppliers earth but you don’t get the required readings you need to use a earth rod as well ?Measuring in feet suggests a very mature trainee.
why is it so many people think they need to TT outbuildings ?
TT wise am I right in thinking even if you use the suppliers earth but you don’t get the required readings you need to use a earth rod as well ?
if you use TN-s earrh and dont get acceptable Zs readings, you've used too small a cable
Yeah all my findings will be checked by my boss and he will supervise me testing etc.Which brings us neatly back to the original question.
OP - tell us what you calculate the cable size you need (and I would recommend you check the actual Ze on the site before anybody runs off buying the wrong cable)
Hope this helps
If a say a customer wanted a garage unit installed but their current CCU it would come off is a plastic enclosure with a single RCD and obviously not an 18th Edition compliant is that OK ? You might recommend they upgrade but do they have to ?
My friend did this but apparently the CPS ( Think Napit) said the main board should be 18th edition compliant. Your thoughts ?
Napit (if thats who they were) don't know what they are talking about is my opinion - you have to realise that the CPS's don't employ many assessors so they are normally sparks doing assessing as a 2nd income. They run around saying different and conflicting things .......... some are OK though
fair. I think he said it’s because the bathroom lights weren’t on an RCD. But from what I understand that wouldn’t be an issue unless the bathroom lights was the actual circuit you are working on. Would that be right ?
I agree - I think he was meaning because the board powering the Garage CU was only a single RCD it was not covering the bathroom lights and therefore it should have a duel RCD.
When you work out Voltdrop I know you are allowed up to 5 % for power and 3% for lighting.
If a distribution circuit after calculation will drop 4.6% by the time it gets to the new distribution board where do you stand on running lighting circuits off the new DB as lighting you can only allow 3% drop ?
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