Discuss Light fitting confusion in the UK Electrical Forum area at ElectriciansForums.net

Jolyonwag

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Removed old bc fitting which had 3 reds in one hole, 3 black wires in the hole next to it and green to a third hole which I assume is earth. It looks like earth is connected to the brass of the bayonet fitting (pics attached)

Installed new bc fitting from toolstation, keeping reds, blacks and earth separate. Then connect blue and brown of new fitting to black and red terminals on the block. Light stays on permanently and can not be switched off.

After testing with neon driver, discover that when switched activated, earth (or green wire previously attached to earth on old bc fitting) returns ‘live’!

I’ve never come across this before, but light work’s correctly when black and brown wires of fitting connected to three blacks and green( previously earth)

Can some one please confirm if what I have done is safe.

I’m used to live, switched live, and neural & earth at the rose!

Thanks in advance
 

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someone has been very naughty here. looks like they were short of a conductor for the switched L, and used what should be earth as a live conductor. my advice is to call in a local electrician as that is a dangerous situation. worst scenario, could lead to a fatality.
 
The neon screwdriver will be totally unreliable and dangerous. Can you indicate the exact terminal the green was in at the old batten holder, one is just a loop in and serves no purpose as such.
 
Removed old bc fitting which had 3 reds in one hole, 3 black wires in the hole next to it and green to a third hole which I assume is earth. It looks like earth is connected to the brass of the bayonet fitting (pics attached)

Installed new bc fitting from toolstation, keeping reds, blacks and earth separate. Then connect blue and brown of new fitting to black and red terminals on the block. Light stays on permanently and can not be switched off.

After testing with neon driver, discover that when switched activated, earth (or green wire previously attached to earth on old bc fitting) returns ‘live’!

I’ve never come across this before, but light work’s correctly when black and brown wires of fitting connected to three blacks and green( previously earth)

Can some one please confirm if what I have done is safe.

I’m used to live, switched live, and neural & earth at the rose!

Thanks in advance
Chuck that neon screwdriver in the nearest bin Mate. potentially a killer
 
Chuck that neon screwdriver in the nearest bin Mate. potentially a killer
Aren’t all screwdrivers potential killers? Stabby stabby!!

it’s the electricity that you don’t know is there that can kill you.

It’s like falling from height. It’s not the fall that will hurt..... it’s the sudden stop at the bottom .
 
Aren’t all screwdrivers potential killers? Stabby stabby!!

it’s the electricity that you don’t know is there that can kill you.

It’s like falling from height. It’s not the fall that will hurt..... it’s the sudden stop at the bottom .
i fell off a ladder once. i pressed the Emergency stop. it didn't work. must have been wired by a plumber.
 
The neon screwdriver will be totally unreliable and dangerous. Can you indicate the exact terminal the green was in at the old batten holder, one is just a loop in and serves no purpose as such.
So, the green was in the more exposed hole (where you can see the tiny screw and the plastic has a gap in it. The other 2 holes had 3 reds twisted together and 3 blacks twisted together, respectively. The baffling thing is that this has been working like this for over 40 years!
I will take on board advice about screwdriver, thank you.
 
It looks like rubber insulated cables, i.e. very old and brittle.
Given it is very easy to damage those cables, and is defying all reason, and there is an apparently live earth wire I really would urge you to take the bulb out and call someone in.
Out of interest, was the light switch disturbed at all in any way as part of this job?
Does the switch only (normally) switch the one light?
 
So, the green was in the more exposed hole (where you can see the tiny screw and the plastic has a gap in it. The other 2 holes had 3 reds twisted together and 3 blacks twisted together, respectively. The baffling thing is that this has been working like this for over 40 years!
I will take on board advice about screwdriver, thank you.
Something odd is certainly going on, as the terminal the 'earth' was in on the old fitting does appear to be for an earth, not for a switched live.

It does need checking over with a proper tester as various issues/errors may be combining. Checking at the appropriate switch may throw some light on the matter, but only safe if done with care and the appropriate circuit isolated.

A safer bet to your neon screwdriver would be a non contact tester, though it's easier to diagnose properly with a 2 pole tester - such as this - though it will only show voltage present when correctly used (Some more expensive ones effectively combine both so they can work with one or both probes)

I'm guessing this installation doesn't have an RCD fitted?

However it has been wired it would appear to be very much not correct and needs investigation before further usage, particularly if there are any metal switches on the circuit involved....

It's possible that the neutral has not been properly reconnected and the light is working because you have connected it from live to earth - but it's also possible (more likely) that the earth has been (very naughtily) used as a live, which would definitely need addressing....
 
I presume that there is no RCD protecting that circuit.

I would strongly urge a call to a local electrician for your own safetey.
 
It looks like rubber insulated cables, i.e. very old and brittle.
Given it is very easy to damage those cables, and is defying all reason, and there is an apparently live earth wire I really would urge you to take the bulb out and call someone in.
Out of interest, was the light switch disturbed at all in any way as part of this job?
Does the switch only (normally) switch the one light?
No, I removed the 3 reds, 3 blacks, and earth from the bayonet fitting. The reds were tightly twisted together, the blacks were tightly twisted together (they had to fit in the tiny holes), and the green is a single wire.
Yes, the pull switch operator the single light.
There is a recently professionally fitted air extractor on a separated pull switch, but the fuse has been removed from the spur because my mother in law doesn't like the way it comes on 'all the time'!

I'm pretty sure this is not connected to light switch, but can't be certain. Also, the light switch was working previously with the extracted 'deactivated'.

I am going to get a professional in, but I'm still curious to find out what is happening here.

Thanks for you patience.
 

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