I tried to get the same information a couple of weeks ago. I explained that I new how to use a megger but I could find specs. for Romex. If you go to the southwire web site they will tell you that 2-50 Meg. is inconclusive. Leading you to believe that over 50 is good. I didn't get the job anyway. Some good hearted person left a site address about a different insulation test that looks to be easier because you can leave everything hooked up. I have not bought or rented this equipment but the site looks interesting. Check out the hipot tester. http://www:hipot.com/index.asp
