A fixation system in use for medium or high voltage switching poles, insulators, circuit breakers, or general devices includes: an insulating housing provided with holes, in which screws are screwed into, in order to fix the device on a support, or a further housing. Inner surfaces of the holes are covered with a conductive layer or layers covering the inner surfaces at least partly. The conductive layers extend toward outside the holes. The conductive layers are conductively connected or connectable to ground potential.