What must be done with the "Selector" lever before hand operating a dual control switch?

Before hand operating a dual control switch, the "Selector" lever must be thrown to the hand-operate position. This step is essential because it directly enables the manual operation of the switch, allowing it to function properly without interference from the automatic or electrical control mechanisms.

The selector lever is designed to switch between automatic and manual control modes. When it is positioned to hand-operate, it disengages any electrical components and prepares the switch for safe and effective manual manipulation. This ensures that the working personnel can operate the switch without causing potential hazards or malfunctions that could arise from leaving the selector in a different position.

Engaging the switch correctly through the selector is crucial for maintaining proper operational protocols and ensuring that all safety measures are adhered to during manual operations.