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Hi all,
Firstly I'm not an electrician but I have done small bits of diy electrical work :) & am hoping that somebody here, may be able to help/explain something I've come across while refurbing a second property.

While swaping the plastic double switch for a chrome one I noticed that the switch has a green gooey substance around the terminals & one switch was wired in twin & earth with a loop from the C terminal across to the C terminal of the other switch. The other switch (controling the landing light) only had a single red with grey sheath going from L1 to the light.

At the brass landing light I found no earth at all :eek: (all other lights & switches are earthed) & the single cable from the switch. Also the light has the same type of single cable connected to the neutral of the light, (this is where it is foxing me) the cable that is connected to the neutral of the light runs directly downstairs to the fuse box & is connected to the earth bar (i found this when I had removed the fuse box cover to wire a socket just below), so now in effect there is an earth (connected to the neutral terminal of light) at the light but no neutral .

I have been out & purchased a multimeter & using a long length of cable ( a helpfull tip given by a B&Q chap in the electrical dept who also advised to visit here...so thanks if you are here) I have buzzed out from one end of the cable to the other to confirm that it is the same length of cable between the light & fuse box & which I can confirm it is.

Questions are
1, can I take an earth from the switch up to the light ?
2, Is the single cable allowed to be used ?
3, How did the light work with no neutral ?
4, should I move the single cable in the fuse box from the earth bar to the neutral bar, so giving a neutral at the landing light ?
5, would it have been wired this way at fuse box but not to neutral so an earth would have been at the fitting because it is a brass light

Sorry this has gone on & on any help/advice will be gratefully accepted :eek:

Thankyou all
PS I have left the whole lighting circuits turned off just in case.
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  • Thread Starter Thread Starter
  • #2
1, You can & should take an earth from the switch or another ceiling rose or JB to the fitting.
2, So long as it's double insulated (2 pvc sheaths) yes you can.
3, The earth is connected to neutral either in the property or back at the substation.
4, I would but only after putting the earth up to the light fitting.
5, Who knows......probably a diy job or a friday afternoon job.

To be totally sure I'd think about rewiring from an existing rose/jb in T/E to the landing light.
The green goo is nothing to worry about it's the pvc leeching due to the cable age, but again if you want to cover all bases get a sparks in to test/inspect (pir) the whole place.

Andy M

  • Thread Starter Thread Starter
  • #3
The Green Goo is degraded Di-isoctyl Phthalate it is a result of a chemical reaction between the plasticiser of the insulation and the copper. This dates the cable to between 1965 and 1971. High Ambient temp accelerates the process. The green goo is toxic and care should be taken when handling it (keep it away from children). Out of interest what did you clean it up with?
Hahaha...you're cracking me up mate!
There are 59,492 threads on here...go for it!!! :)
I think the way he's going he might just do it

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