When the power switch is on the inspect pane displays 'Power: On', and the center of the power switch shows a pale circle. Appliances won't connect directly to a switch, they only connect to conduit. A switch can be placed directly adjacent to a battery or other power source, but the player will probably find it desirable to place the switch close to the appliances it's meant to control. While one of the switch's connectors must connect to conduit to a power source, any or all of the three remaining connectors can be used to create branches. To construct a switchable circuit simply place the power switch along a line of conduit between the power source and the appliances. A colonist with the 'flick' job type will flip the switch. The 'Toggle power' button is used to request the switch to be flipped. It provides an efficient way to control power to several appliances all at once, such as a large array of improvised turrets.

A power switch is used to toggle power of the conduit lines connected to it.

Rimworld power not working