Insulation green stuff 3

[ROBONUC]

I have a significant number of control cable wires. Standard gray control switch wiring #8 and #10 that is oozing a green sticky substance. It has no odor. Has anyone seen this before or know what it is?

 

[electricpete]

Never heard of it.

I think you may get more responses in the electric power engineering forum.

 

[peebee]

Posting a couple pictures wouldn't hurt either.

 

[busbar]

Long Shot — “Green-goo ooze” is a slang term for electroendosmosis, which is mentioned in an NEC fine-print note. For it to occur, though, there has to be DC potential, moisture and thermoplastic {e.g., PVC} insulation.

99NEC310-13. FPN: Thermoplastic insulation, where used on dc circuits in wet locations, may result in electroendosmosis between conductor and insulation.

 

[jbartos]

Suggestion: Visit

http://www.edstubbs.com/id22.htm

for:
Thermoplastic insulation, where used on dc circuits in wet locations, may result in electroendosmosis between conductor and insulation.
(under "Stranded or Solid Conductors on DC circuits 6/30/02&quot

 

[jbartos]

Suggestion: Visit

http://www.electricianeducation.com/search_term_index_NEC_2002.htm

for electroendosmosis reference in NEC 2002

 

[pablo02]

I have seen this in older power plants on 125 vDC circuits as mentioned by busbar and jbartos -- as their explanations imply, it is a chemical reaction with the copper (the source of the green color -- my chemistry fails me but I think it's a reaction with the chlorine products in the insulation as a result of the DC in the presence of moisture)... as I recall, it is also slightly acidic...