Main Switches
All electrical equipment of industrial machines must be equipped with a Main Switch. This must permit disconnection of all the electrical equipment during cleaning, maintenance and repair work, and other extended periods when it is stationary.If the main switch serves simultaneously as an emergency stop switch, its handle should be red. Otherwise, black or gray handles are recommended.It should be padlockable in the off position.All active conductors are to be disconnected from the main. The breaking capacity should be sufficient to break the current of the largest motor in a blocked state together with the sum of the operating currents of the remaining motors or loads.The main switch may fulfill the function of an emergency-stop switch on certain machines. The handles must be red on a yellow background. The contacts of a manually operated emergency stop switch have to be opened by force .