I was chatting to a customer yesterday about his combination oven. He mentioned that whenever he used the oven with the enamel tray on top of the wire rack the oven started arcing. As I then explained, the reason is that the metal tray was touching the wire rack and this was causing the arcing. The accessories as supplied with most UK Panasonic combination ovens as shown in the photo should be used as follows.
The glass tray and roller ring must be used all of the time on any function. The enamel tray and wire rack should not be used on microwave only. The enamel tray should be placed on top of the glass tray on grill, convection or combi settings. It serves 2 purposes. To catch spillage as the food cooks and to reflect heat from the grill element away from the glass tray. The wire rack can be used on grill and microwave/grill combi settings. Its job is to raise the food either nearer the grill element in the roof of the oven or to keep it off the tray to allow hot air to circulate. The wire rack will sit inside the enamel tray and will operate ok because the rack has insulated silicone feet to prevent metal to metal contact. The enamel tray should not be used on top of the wire rack because there is no insulation between the metal items.
If any of the parts become damaged they may well arc. If they have already arced they may well arc anyway especially if the enamel coating has become chipped or burned.
All of the accessories are available for current models of Panasonic and we also sell the packs of 3 silicone feet as a spare.