Old lighting wiring (all black)

[Eldre]

Untitled

• Eldre
• 9 Dec 2012
• 1

Hi all. First post so be kind

Have just taken a really old fitting down as it had a dodgy connection. The cables weren't into any kind of block on the fitting, just black taped together, so everything is a bit of a mess.

The red bundle of cables weren't connected to anything.

The other cables are sheathed black as far as I can tell.

The single cable on left I believe was connected to a red cable on fitting (hard to tell as everything is a black gooey mess!)

It's a landing light, so are the two together for the switch downstairs and up, and the other the live feed? Can I use them in this condition, or is the residue a fire hazard?

I can't see any earth, but am going to have a poke around for it in a minute.

I only want to hang a simple pendant so I can have some light until electrican fits all my lights.

Any help would be much appreciated.

 

[bernardgreen]

Sometimes it is necessary to be ( apparently ) cruel just to be long term kind. Short term pain for long time pain free.

The three red wires are [1] live feed to the lamp, [2] live feed to another lamp and [3] live feed down to the switch for this lamp. None of these connect to the lamp itself. If you fit a ceiling rose these will all go into the terminals marked LOOP

The two blacks twisted together are [1] neutral feed to the lamp and [2] the neutral feed to another lamp. These connect to the neutral of the lamp.

The single black is the switched live back from the switch and connects to the live of the lamp. It should be sleeved with red to show it is a live wire and not neutral. You need to mark it so you know which black is the switched live when you ( or the electrician ) separate the blacks while fitting the ceiling rose to tidy up the wiring.

If there are no earths you cannot safely use metal fittings or switches. Even if there is an earth wire at this lamp you cannot be sure it is connected at the other end so again no metal fittings.

It is a mess, live and neutrals seem correctly connected but installed badly. The earth needs to be verified.

 

[JuxZeil]

I'd be very careful with the poking about bit. As too the goo, isolate the circuit From the mains (obviously) and double check with a multi-meter that there is no juice on any conductor. Then just clean with WD40 or the like.

 

[bernardgreen]

Then just clean with WD40 or the like.

How long then before power can be turned back on ? Drying time of WD40 is how long ?

I do not think cleaning with WD 40 is a good idea.

 

[EFLImpudence]

Wipe it off ???

 

[Eldre]

Thanks for the fantastic replies guys, especially bernardgreen for the explanation - much appreciated.

I could leave the upstairs lights off for tonight if need be, and just plug in a few lamps.

I have WD40, so could clean with that. It evaporates quite quickly, but not sure how it could react with old wiring.

Now please excuse the stupid questions...

The red cables bundled together were not connected to the old fitting. Just taped together (in their own little dodgy loop I suppose!) what are the implications of leaving them like that? I know it's easy to connect them to the plastic pendant I have, but just wondered out of interest.

Would I need to separate the two neutral feeds to fit into the pendant? I intend to anyway for cleaning, but once again wondered what good practice / legislation was.

I do try my best to leave electrics to the experts, but today was a bit of an emergency mission. I have an electrician booked in for my new kitchen, so will chat to him then about rest of house.

 

[JuxZeil]

Then just clean with WD40 or the like.

How long then before power can be turned back on ? Drying time of WD40 is how long ?

I do not think cleaning with WD 40 is a good idea.

Sorry for the late reply, visitors.

The WD40 cuts through tape glue and such really well and wiped off well should evaporate within 30 mins. As it acts as an isulstor when dried it's best to cut back the conductors a tad past the bare wire to make sure you get a good connection.

WD40 works well on old point and rotor arm car ingnition systems too.

 

[AndyPRK]

looks like the green liquid coming out of the pvc to me.

alchol or aftershave will remove it

 

[RF Lighting]

WD40 is none conductive. The WD stands for water displacement, and it's brilliant for flooded joint boxes etc. A good liberal spray of WD40 and you back in action.

 

[bernardgreen]

WD40 is none conductive. ~~~ ~~ good liberal spray of WD40 and you back in action.

Not always, some high voltage ( >> 230 volts ) communications equipment did not survive a wash with WD40.

 

[RF Lighting]

It doesn't conduct when tested with my IR tester at 1000V DC

 

[Eldre]

Quick update - pendant up and working fine. I left the bundle of reds as they are, and didn't play with them.

I ended turning off everything in the house, as when I turned off down and upstairs lights on the board, there were 2 wall lights in the living room that were still live!

I assume the previous owner must have run them off the mains?

Time for a re-wire I think! There's not enough sockets in the house anyway.

Thanks once again for all your help.

 

[Taylortwocities]

A rewire is a good idea, but my not bee essential.

That green goo is a common problem with PVC wiring of a "Certain age".

The plasticiser used at that time has a reaction with the copper conductor/heat which produces that foul goo after 20-30 years..

There's no solution (even WD40!") that will fix this issue but it has been found that the goo is only unsightly and not harmful. A rewire isn't needed unless the IR figures are outside the specific requirements.


PS
I have never used WD40 on low voltage installations and I'm not going to start now.

Note to self: must read the WD40 tin

 

[RF Lighting]

The stuff on the OP's cable looks to me more like tar / pitch rather than green plasticiser goo.

 

[Iggifer]

It doesn't conduct when tested with my IR tester at 1000V DC

A 9VDC calculator didn't survive a wash with WD40, I was most disappointed, was a great calculator