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For example, insulator Z has a threshold voltage of 1000V. After exposing insulator Z to more than 1000V, its breakdown threshold voltage is now 800V. Can I lower the threshold voltage further with high-voltage or can I only lower the breakdown threshold voltage once?

Here's a quote from the source material I'm reading that has me asking this question.

Many solid insulating materials exhibit similar resistance properties: extremely high resistance to electron flow below some critical threshold voltage, then a much lower resistance at voltages beyond that threshold. Once a solid insulating material has been compromised by high-voltage breakdown, as it is called, it often does not return to its former insulating state, unlike most gases. It may insulate once again at low voltages, but its breakdown threshold voltage will have been decreased to some lower level, which may allow breakdown to occur more easily in the future. This is a common mode of failure in high-voltage wiring: insulation damage due to breakdown. Such failures may be detected through the use of special resistance meters employing high voltage (1000 volts or more).

I'm mainly interested in the possibility of lowering the voltage threshold further by repeated high-voltage breakdowns as described above. I understand that different insulating materials have different properties, however I don't know enough to be anymore specific. Maybe you can provide me with an example if that would help?

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  • \$\begingroup\$ Is your described behavior coming from some real datasheet, or are you just making it up as a hypothetical? \$\endgroup\$ – Scott Seidman Jun 24 '16 at 21:05
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    \$\begingroup\$ In any case, it doesn't sound like an approach I'd want any product designed around. \$\endgroup\$ – Scott Seidman Jun 24 '16 at 21:06
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    \$\begingroup\$ Manifacturers don't specify the "death spiral" characteristics, they specify how to avoid it... \$\endgroup\$ – MarkU Jun 24 '16 at 21:14
  • \$\begingroup\$ It's a hypothetical, and I made up the values. I want to know if there exists limitations to this as I already asked. For example, if there are no limitations, then I could breakdown the voltage for rubber gloves to the point where they wouldn't protect me from electric charges. \$\endgroup\$ – Wandering Fool Jun 24 '16 at 21:14
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    \$\begingroup\$ The other aspect to remember is that the insulation will only break down in the region of high stress. The rest of it will be unaffected. On a slightly related topic, I know that in some industries 2-layer rubber gloves are the standard. The inner layer is yellow and the outer is red. The gloves are inflated for inspection and if any yellow is visible through surface wear or cracks then the gloves are discarded. \$\endgroup\$ – Transistor Jun 25 '16 at 23:35

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