What do you think about this From Southwire
Installation and Application Guide
for 600V Conductors
:
Acceptable: A megohm meter reading of 50 megohms or higher should be considered
acceptable.
Investigate: A megohm meter reading of 2 to 50 megohms may be used for deciding when to
investigate the cable installation. In most cases, a 2 to 50 megohm reading does not indicate
the insulation quality. Therefore, 2 to 50 megohms should not be specified as a pass/fail value.
These readings are usually associated with long circuit lengths, moisture, or contamination.
Ends of conductors that are dirty or damp may need to be cleaned and dried.
Unacceptable: Readings less than 2 megohms will most likely indicate damaged insulation or
severe test conditions