Electrical, home lighting at top of stairs

FreeBear

nofoollikeold said: A neon screwdriver is not a good enough test.

Some of those neon screwdrivers (mainly cheap "Made in China" ones) can be dangerous and give you a nasty shock.

As for the OP's wiring, it looks to be pretty old - Red, black, and yellow/green went out in 2006. Yellow/green superseded plain green for earth in 1977, so this wiring is probably somewhere between those two dates.

A full and proper inspection of all the wiring is probably in order just in case there are other bodges hidden up.

Risteard

FreeBear said:

nofoollikeold said: A neon screwdriver is not a good enough test.

Some of those neon screwdrivers (mainly cheap "Made in China" ones) can be dangerous and give you a nasty shock.

As for the OP's wiring, it looks to be pretty old - Red, black, and yellow/green went out in 2006. Yellow/green superseded plain green for earth in 1977, so this wiring is probably somewhere between those two dates.

A full and proper inspection of all the wiring is probably in order just in case there are other bodges hidden up.

All phase testers can be dangerous if the resistor fails in them. They shouldn't be used by anyone. A proper two pole voltage indicator complying with GS 38 is the only correct item for this.

gingerbreadmen

By looking at the photos you posted its quite obvious why the light is on permanently. If you cant see that OP then please don't touch and get a electrician out. Good luck with that at the moment. 

knightstyle

This sort of thing happens a lot when an unskilled person changes a light fitting.
I always sort these out by:
1. Isolate at the consumer box.
2. Disconnect all the wires.
3. put all the red/brown wires into a connector.
4. Put all the earth wires into another connector.
5. Separate all the black/blue wires and switch on the power.
6. Test each black/blue wire to see if it is live, if it is this is the live feed to the light so mark it with red/brown sleeving.
7. If not switch one switch and repeat no.6.
Then having identified the wires install ceiling rose or light fitting as normal.
If this does not work then and only then look at the switches and wires going to them.

Risteard

knightstyle said:

This sort of thing happens a lot when an unskilled person changes a light fitting.
I always sort these out by:
1. Isolate at the consumer box.
2. Disconnect all the wires.
3. put all the red/brown wires into a connector.
4. Put all the earth wires into another connector.
5. Separate all the black/blue wires and switch on the power.
6. Test each black/blue wire to see if it is live, if it is this is the live feed to the light so mark it with red/brown sleeving.
7. If not switch one switch and repeat no.6.
Then having identified the wires install ceiling rose or light fitting as normal.
If this does not work then and only then look at the switches and wires going to them.

Not a safe way of doing things. Please ignore this advice. 

mwarby

Yep I agree its not safe and method described isn't foolproof you may end up with 2 blacks live, as one of them will the return current from another bulb (which would be lit if there was a return path). It's alo possible that the switch itself has failed or someone has error in replacing one of them

If you don't understand how a lighting circuit should be wired leave it to someone who does, especialy with mains smoke alarms (if interlinked they will have a signal wire, might not too kindly to have 240v shoved down it). At the moment you have 1 light you can't turn off, there is the risk of injury and loosing more lighting if you try and DIY a fix, much better to wait until someone can fix it properly

mwarby

Its also worth bearing in mind that using multimeters on live mains is not without risk. The cheap ones most of public can justify (me included) have very little in way of protection against user error, if you use it in current mode you are putting a short across the mains(which will be dramatic), in other modes(other than volts) you may damage the meter in varying degrees

mwarby

It is quite clear though that there is an issue which needs to be fixed(by a competant person), if nothing else so that there is no risk of metal work becoming live or arcing

Risteard

mwarby said:

Its also worth bearing in mind that using multimeters on live mains is not without risk. The cheap ones most of public can justify (me included) have very little in way of protection against user error, if you use it in current mode you are putting a short across the mains(which will be dramatic), in other modes(other than volts) you may damage the meter in varying degrees

Absolutely. This is where my mention of GS 38 compliance is critical for checking for voltage (or absence thereof).