Insulation resistance test

[simbin]

Hi. Has anyone had a problem with a Megger MFT1552 with regards to insulation resistance testing? All if a sudden mine won't work & displays 500mA. I've tried a couple of new fuses but still nothing. Everything else works fine....

 

[trev]

Sorry mate

 

[Meggerman]

There are two more fuses inside the 1502 series that are not user accessible. You need to pick back the top sticker to reveal four screws, then you can open it up. If you have carried out I/R on a live circuit that is probably what has happened, they wont let you start I/R on live terminals but if you are already meggering then....pop. The new 1700 series meggers will let you I/R a live circuit with no damage (they make a big deal of it on their ad!).

 

[simbin]

It seems to have stopped working AFTER it was calibrated. I fuse I've tried is the same as the original one.