Thanks again anorlunda, I have found useful link http://www.posterus.sk/?p=16307 . It is more clear now.
Although the phenomenon is not fully explained in science yet. Especialy I can't see very good indicator desriribing this material property. Only usefull information for me is that presence...
Yes that's what i thought too, it's called also electrical treeing. Some paths are being ionized more than others in insulation, this could explain decreased resistance or higher currents through the insulation. Thank you anorlunda.
Is there any detailed description why is this happening, or...
Hello everyone,
From what i know electrical resistance for metals is a constant, but in fact it varies with temperature but not voltage. Explanation for metals and temperature is something like "heat, which is in fact average speed of electrons, does obstruct tranmission of other electrons...