megging wire

[don_resqcapt19]

Rocky,

Maybe our friend, Sokkerdude, could just go with a Fluke 87 and fly through on a ohm scale reading (87's go past 40 megaohms) on a walk around, with the owners rep, to instill some confidence into him that things are okay?

There is no commonly available and used test that can prove that the conductors are ok. Sure you can meg it, but that does not tell you that there is not bare copper in the raceway unless you have some condutive medium.

Call me paranoid, but I've just caught way too much trash with a megger to write them off, or pencil whip the paper.

Sure it can and does catch many problems, but not all. I have seen number of failures from poor installation practices that resulted in bare copper in the raceway and still passed the megger test that was required by the contact documents. The use of a megger just doesn't prove, what most seem to think that it does.
Don

 

[ramsy]

Have you found any evidence of this (helium flooding) being done on conductors under 600 volts?

NO. But, after some more homework on "electrically conductive gases" I see plasma doesn't stay conductive for long. Helium ions only extend a short distance from the ionizer (direct current arc), release large amounts of energy (a 10,000F flame) then reverts to a normal gas (non-conductive). Oops sorry folks, Helium is the wrong gas.

Thinking ozone might be conductive, I found some cord & plug ozone-gas blowers. But, the Ozone MSDS says ozone is severly toxic to humans, and it can explode in contact with common elements like copper and organic compounds. Lighting this cannon in some underground conduit wouldn't be good for electrical equipment either.

If there is a safe & conductive gas out there, its not easy to find. I leave it to the chemistry engineers to figure out.