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Post by Firefox on Sept 11, 2014 12:03:30 GMT
A Q for X n brown Etienne Le Croq and anyone else who knows about domestic wiring... After my recent flood, the ground floor lights stopped working. I have got them working again now. I traced the issue to the ceiling rose nearest the fuse box. This has more connections coming into it, and I think it is wired to the fuse box with another wire going off from the connector looping round the other roses to provide the neutrals and onother wire looping off for the lives. Anyway I tested 240 V AC between the incoming live and the green/yellow earth but only 5-20V AC between the live and the black/blue neutrals. The earth wire is for connecting to large metal lights such as chandeliers which need an earth. Most domestic lights don't, and it just goes to a spare terminal in the rose, connecting to nothing. Since earth is the same potential as neutral, I just connected the earth into the neutral block, and hey presto, everything works. 1. Any idea why the neutral stopped working? I will clean the wires and rescrew them, but I did try to test the potential on the wires themselves not on the block and only got 5-20v between those and live. 2. Have I done anything dangerous connecting the earth into the neutral block. They should be the same potential as neutral is just another earth?
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Post by outtolunch on Sept 11, 2014 12:22:22 GMT
neutral is not another earth it is possible to get a shock off a neutral line , the reason you have no reading from live to neutral is because there is a break in the neutral wire back to the distribution box
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Post by n brown on Sept 11, 2014 13:05:08 GMT
not a good idea to join neutral and earth !
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Post by Oldish Hippy on Sept 11, 2014 13:29:13 GMT
dont forget that the switch line wil probaly be a black and a red wire which both will be live ie a wire goes from rose down to switch with the red wire and the return from the switch will be on the black wire {as in 1.5 cable which consist of red black and a copper wire which is the earth when use it is sleeved at switch and fittings}look up wiring switches and it will explain what imean and it get fun on two way switching ie a switch one side of the room aand a switch the other side of the room and the lighting ring is basically a loop with tap out for the lights so it goe from mains round the loop and back make sure that it goes back to same fuse on board that is the basics of lighting
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Post by Firefox on Sept 11, 2014 13:43:08 GMT
This is a good article I just found: www.emfs.info/Sources+of+EMFs/distribution/Neutral+earth+connections.htmBasically it will "work" and is not inherently dangerous, but it is not in the code. It could cause ELCB to trip (my fuse box is the old type - no trips just fuses) It could also cause emf field in the earth wiring. Thanks for the comments. Any further ones are welcome! What I will do is clean and refix neutral wires in the rose. I don't see any reason for a break at the moment.
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Post by n brown on Sept 11, 2014 15:02:57 GMT
the neutrals all end up joined together so a continuity tester should find any break easily enough=power off of course !
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Post by Oldish Hippy on Sept 11, 2014 15:06:21 GMT
where a lot of folks get confused is the live returns from the switches which are done on the nuetral wire {black} ans where they are not marked as lot of peeps dont mark the returns as live i used to use a red sleeve over the nuetral {black} wire at the switch and the ceiling rose failing that it was always a red tape and used to always make sure that the live feed from the switch was always done with the red wire
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Post by Etienne Le Croq on Sept 12, 2014 6:00:28 GMT
I don't know anything about 240v wiring Chap, 12v is my absolute limit.
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Post by Firefox on Sept 12, 2014 12:03:35 GMT
I don't know anything about 240v wiring Chap, 12v is my absolute limit. 14.5 v from an alternator ? Still not tried to fix my wiring yet - I'll have a go this weekend.
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