Replacement:The switch shall be of momentary contact type.For single phase grinders, either.- the mains switch shall automatically switch off the motor as soon as the actuating member of the switch is released and shall have no locking arrangement in the “on” position,or- the tool shall not restart after an interruption of the mains supply without releasing and reactuating the switch. In this case, a lock-on device is allowed, provided that, two dissimilar actions are necessary to lock the switch in the “on” position. In addition, only a single motion to the actuating member of the switch shall be required for the switch to automatically return to the “off” position. The restart prevention device shall have a Safety Integrity Level SIL 1, in accordance withEN 62061, or a performance level PL = b in accordance with EN ISO 13849-1.For all other tools, a lock-on device is allowed provided that two dissimilar actions are necessary to lock the switch in the “on” position. In addition, only a single motion to the actuating member of the switch shall be required for the switch to automatically return to the “off” position.Compliance is checked by inspection and manual test.