Switch with auxiliary and main contacts

Switch with a fixed set of contacts and a movable set of contacts, the fixed set of contacts comprising at least one pair of fixed contacts (1, 2) arranged a distance apart and each having an auxiliary contact part and a main contact part (7, 8 and 5, 6 respectively) and the movable set of contacts comprising at least one auxiliary contact element (11, 12) and a main contact element (9, 10), which, when the switch is closed, are in contact, under mechanical pre-stress, with the surface of the auxiliary contact part and of the main contact part (7, 8 and 5, 6 respectively) of the pair of fixed contacts (1, 2) and bridge the distance between the free end edges thereof facing one another and when the switch is closed the main contact element (9, 10) makes mechanical and electrical contact with the main contact part (5, 6) of the fixed contacts (1, 2) only after the auxiliary contact element (11, 12) has travelled a distance over the surface of the auxiliary contact part (7, 8) of the fixed contacts (1, 2) after the auxiliary contact element (11, 12) and auxiliary contact part (7, 8) of the fixed contacts (1, 2) have come into contact, characterised in that said travelled distance is at least 2 mm.