There is a lot of mystique surrounding megger use. I think this is because most folks have only seen them used by a "special" person, in an industrial setting, and were not allowed anywhere near the tool. Of course, this was because of two factors:
-Meggers were once only one price: expansive; and,
-The sort of testing done in an industrial setting is very dependent on technique and documentation.
We're not talking about that sort of testing here....we want a quick & easy pass/fail test for our circuits before we power up. Sort of a souped-up continuity test. The value? Well, sometimes the wire gets damaged, sometimes we forget to tighten all the screws we don't use, and sometimes that $##@ ground wire get pushed too close to a 'hot' screw when we push the device into the box.
That's why I suggested the cheap meter with the LED display. There's no need to translate a numerical value into "good" or "bad;" the meter does that for you.
Another approach might be to power up for the first time through a GFI. 5mA of leakage current is a pretty good indication that there is a problem somewhere- and without making scorch marks on the walls!
Now, this is for "new work" only. If you are checking for insulation that has degraded from age, been damaged by lightning or fire, etc., then the fancier tests have merit. I just would not ordinarily do a "polarity index" or "saturation" test for the usual circuit.
