What is considered a good Meg reading?
The recommended minimum insulation resistance to ground when measured at, or corrected to, 40 degrees C, is the reated machine voltage potential in kilovolts +1, in meg ohms. Unit should be meggered 1 10 minutes for a polarization index value. 2.0 is considered a minimum value when you divide the 10 minute reading by the 1 minute reading. The PI value is the result of that division.