Davebones
Senior Member
- Location
- North Of Tampa Fl
I have a Fluke 1507 insulation tester . We have a 150 HP motor ( 480v) that the insulation has been showing signs of breaking down . Its reading 130K ohms at 500 vdc now. My question is when I first started the test the megger only showed it was putting out around 100 volts when the test was first started . Is this to prevent any more damage to the insulation since its going bad ? The voltage readings started going up as the insulation readings got a little better . it stopped around 250v at 130K . Never noticed this before just curious ............