PAT IR fail on old cooker with rods not cable

[Msitekkie]

I am PAT testing a very old 2100W Belling tabletop cooker that the customer is keen to keep & paying me to repair. It fails a L-E or N-E IR test at 0.46 M ohms.

Internally the cooker uses bare rods rather than cable.
I replaced the old cable & plug and L-N I get > 1999, but L-E or N-E still fails. I am thinking this is probably working as designed, but wondered about putting sleeving on the rods to (hopefully) get a pass mark on the test.

Interested in people's views/similar experience.

 

[Lucien Nunes]

This is normally due to moisture in the heating elements. When they begin to heat, first the insulation resistance falls as the moisture moves towards the cold ends and condenses, then slowly rises as it is expelled. If you leave it on long enough, and it doesn't trip the RCD during the warm-up, it will probably go up into the megohms.

 

[Msitekkie]

This is normally due to moisture in the heating elements. When they begin to heat, first the insulation resistance falls as the moisture moves towards the cold ends and condenses, then slowly rises as it is expelled. If you leave it on long enough, and it doesn't trip the RCD during the warm-up, it will probably go up into the megohms.

That did the trick. Great tip, many thanks