A cooker unused for a longer period of time!
I know internal recommendations of a well known manufacturer, that you are supposed to run and heat the equipment for some time in order to reduce leakage current.
In case of a TT installation with rcd tripping it is recommended to isolate the cooker/oven and to unmount (!) PE conductor in order to achieve drying. Better don't touch it in this phase.
It is not worth to meg the device (if it has not a low ohm failure) before half an hour of ordinary service.
This is not my personal idea!
