Cable plasticiser reacting with copper.

[dtec dave]

Firstly no Ghostbusters jokes!!

Was called out to a job yesterday where a light fitting had been 'buzzing', upon inspecting it I saw the terminals and cable were covered with a 'green slime'. After a quick Google I found out this is quite common and that it the plasticiser of the cable reacting with the copper over time. The customer also wants a consumer unit change so was wondering what the general consensus would be..walk away or procceed with consumer unit change if the cables pass an IR test?

 

[telectrix]

depends on whether the cables test OK, whether or not you can clean the slime off, and the size of the customer's wallet. ideally the cables should be replaced, they' around 50+ years old, but at the end of the day, it's your call.

 

[Toneyz]

John Ward has also done a video

 

[Andy78]

I have only come across this a few times. Each time was due to short circuit problems. Each time the IR values were incredibly low.

 

[Strima]

I've seen it a few times. I've cleaned it off and IR results were decent enough.

It seems to appear where heavy loads are attached such as tumble driers, panel heaters etc. and only near the terminations. At a guess thermal effects increase the severity of the goo???

 

[Andy78]

I've seen it a few times. I've cleaned it off and IR results were decent enough.

It seems to appear where heavy loads are attached such as tumble driers, panel heaters etc. and only near the terminations. At a guess thermal effects increase the severity of the goo???

I have found that too. In one instance the goo was evident in most circuits, but particularly on the lighting. There were chandeliers all over with incandescent lamps and the total load pulled was nearly 7 amps on the 6 amp fuse wire. These fittings had been in place since the rewire when this cable had been put in.

The IR readings on other circuits were low but just about compliant, but the lighting circuits were shot.

My theory was that the heat from the load exacerbated the breakdown of the plasticiser, and the lack of plasticiser contributed to the poor readings of the insulation.

 

[Midwest]

Concur with all above. I would do minor works if that particular circuit tested okay. However, I would not do a CU change with evidence of the green stuff, as you kinda take on the responsibility for it.

I've come across it a few times, once replacing a damage socket and other similar situations. Last one was a request for CU change; gave the client some documents on the subject, and they elected for a rewire. The existing install was in a bit of a mess, so it wasn't just the goo.

 

[telectrix]

any member needs to know all about goo....... just google goo

 

[GBDamo]

Is it just me that carries a bottle of Fairy liquid?

"See that green stuff? Needs a rewire love"

What?

 

[littlespark]

Is it just me that carries a bottle of Fairy liquid?

"See that green stuff? Needs a rewire love"

What?

"What?", says the customer? "Dodgy wiring smells of lemon?

 

[bxman]

Could these instances possibly relate to someone using certain types of vaping fluid in the vincinity of the ceiling light fixtures. Twin and earth wire used so wiring cannot be that old. Substance found can be absorbed into kitchen tissue - viscous green liquid, tacky to the touch.

 

[Midwest]

Nope, think that’s a good example of green goo.

 

[Andy78]

That's a prime candidate for the green goo in those ceiling roses. Cable dates from before 1977 as solid green sleeving is used which is the right era for problem cable. Looks like every green goo example I've ever found too.

 

[Strima]

If that was linked to vaping fluids then the brown and blue flex insulation would also be showing signs.

 

[bxman]

If that was linked to vaping fluids then the brown and blue flex insulation would also be showing signs.

Thanks folks
Green goo it is then
only evident on the fittings with the solid green earth sleeving

No chance that is going to test out OK. some of it is not much more viscous than water .

 

[Strima]

No chance that is going to test out OK. some of it is not much more viscous than water

I have green goo in my house and it tests out OK.

 

[Midwest]

If I had green goo in my house, I'd eventually rewire whether it tests ok or not. When I've ever I've come across it with customers, I've gave them the information to make an informed decision. If they asked my opinion, I would tell them to rewire. But thats my personal opinion.

 

[bxman]

I will post up some more photographs if I can to-morrow out of 3 ceiling fittings 2 are liquid goo and one is dry very different to look at the dry one was not exposed to the vapour all other light fittings in the house were clearly rewired later on as fitted with the normal earth sleeving

 

[SparkySy]

I used to come across it loads years ago doing council work in concrete high rise blocks with steel conduit installation, some of the stairwell lighting conduit in one was literally running with the stuff and IR shot.
Have seen it in a few houses on twin and earth too but not so regularly.
I would advise that the cable is in poor health and let the customer make the decision!

 

[bxman]

Here are a couple more photos showing the three light fittings affected by the green goo. They clearly show the difference between the dry and the wet type of greening. The fittings affected by wet goo do not test out satisfactory. Appreciate your help and any more comments. H

ope this will be helpful to others confronted with a similar problem.