Quote Originally Posted by rbalex View Post
The old "crank-type" were DC. Some newer units MAY be AC; don't know, don't recommend them. But, as I said, they practically guarantee unnecessarily destroying conductors. I believe most conductor manufacturers recommend against AC insulation resistance tests.

A 500Vdc setting is already below the conductor rating (600V) anyway.
1000 VDC is the recommended voltage for 600 AVC conductors.