Insulation Breakdown? - Possible High Heat/Humidity

[mpulse]

Hi All,

first post with a general enquiry regarding insulation degradation. Ive just had a look at a 40 year old house which has very little wiring addtions or changes done to it since build other than the CU being changed out to mcb. Problem I am seeing on various sockets/switches is a greenish liquid running from the socket/switch locations down the facing walls of there postion. On inspectin it appear the neutral wire has moisture on it and is oozing green liquid? the insulation around the wiring appears fine and unbroken but for the life of me I have no idea where the liquid and the colour is coming from? anyone any ideas other than my high heat/humidity theory, the house is like an oven constantly

 

[bugsy]

http://www.google.co.uk/url?sa=t&rct=j&q=green%20goo%20in%20electrical%20installation&source=web&cd=4&sqi=2&ved=0CFgQFjAD&url=http%3A%2F%2Fwww.eng-tips.com%2Fviewthread.cfm%3Fqid%3D129440&ei=4ocQT7qfGsyp8APa4Pj3Aw&usg=AFQjCNGFANVZvKJWwOCgAhK5ntznpSkkaQ&sig2=FZU60fRIe879Vw_DaJsXlQ

Im just being lazy

 

[MarkieSparkie]

Green gunge (also known as green goo) is sometimes seen exuding from the ends of older PVC insulated and sheathed cable. It is normally seen in cables made in the 1960s and 1970s, but not generally seen in modern PVC cables.

Its origin is the plasticiser used to provide flexibility in the PVC polymer compound. This is generally di-octyl phthalate, which over time or with excessive heat has reacted with the copper conductors to produce copper phthalate (hence the green colour) suspended in the liquid plasticiser. The material is a health concern, so should be handled with care – gloves should be used and waste disposed of properly.
Although there does not appear to be a problem with the electrical performance or safety of the cable itself, any exuded gunge should be removed as it can cause corrosion or affect the action of switches and terminations, potentially resulting in tracking / overheating. It can also cause cosmetic problems such as staining. The affected circuits should be rewired as soon as possible.

 

[mpulse]

Thanks Bugsy obviously my Google skilss suck lol.

"The green slime, or green goo, is degraded di-isoctyl phthalate and is considered to result from a chemical reaction between the plasticiser of the insulation and the copper conductor in the pvc cable. Between 1965 and 1971 the temperature performance of pvc was uprated by the inclusion of an anti-oxidant into the pvc compound. An unappreciated side effect was that the anti-oxidant encouraged production of the exudate.
There is evidence to suggest that high ambient temperatures accelerate the process. The exudate is of low flammability and low toxicity. Although unsightly, it does not reduce the electrical integrity of the conductor or the insulation. However, the exudate may have detrimental effects on both accessories (in appearance and functionality terms) and their surrounding decorative finishes."

This sounds exactly like what I viewed, dont know wither to advise a rewire or just change switches/sockets and tidy up?

 

[Specialist]

If you Just change accessories & clean up, it's not going to stop the problem and your customer's just going to call you back & complain. If it's that bad then your best action would be to advise a re-wire.

 

[telectrix]

tidy it up, IR all cables , and recommend annual checks to see if there is ant further deterioration. unless the client is prepared to pay for a rewire, in which csae, crack on with it.

 

[Marvo]

Once a cable starts to exude this goo if you clean it up does it continue ad infinitum or does it stop after a while?

 

[Specialist]

Seen it on several occasions where after a few Weeks / Months it comes back again. It's not a pretty sight especially all over a customers Newly Decorated walls.

 

[bugsy]

Tell them it's caused by aliens attracted by the electromagnetic effects and the only solution is to rewire in FP get your testers out and say their on lay lines

 

[Specialist]

Your Nuts, But i like it:tounge_smile:.

 

[mpulse]

I appreciate the feedback all, but this is my Dads place and to be honoust unless his house is going to self combust I would rather leave it. Im capable of the rewire but punching the **** out of the house I was born in doesnt sound appealing to me. Does anyone know if this corrosive action actually happens else where other than the tale's? Im just assuming its an oxidising issue in the switch cavity?

 

[Specialist]

I appreciate the feedback all, but this is my Dads place and to be honoust unless his house is going to self combust I would rather leave it. Im capable of the rewire but punching the **** out of the house I was born in doesnt sound appealing to me. Does anyone know if this corrosive action actually happens else where other than the tale's? Im just assuming its an oxidising issue in the switch cavity?

Tails ? You said it was running down the wall at fittings.