Knife switch

A knife switch opens or closes an electrical circuit by moving a conductive blade into or out of contact with fixed terminals. Its exposed, hinged blade makes the switching action visible.

Connect

Electrical contact: A conductive interface through which electric current passes between components. The blade must make a reliable conductive interface with each fixed terminal.
Electric circuit: A connected path through which electric current can flow. The knife switch changes whether its circuit has a conducting path.
Battery disconnect switch: A switch used to isolate a battery from part or all of an electrical system. Knife-switch designs can provide a direct, visible way to disconnect battery circuits.
Toggle switch: A switch operated by moving a small lever between positions. Its enclosed contacts contrast with the knife switch's visibly moving blade.
Air gap: A separation between conductive parts that prevents current flow when its insulating strength is sufficient. Opening the blade creates a gap that interrupts the circuit.
Electric current: The rate at which electric charge passes a point. The switch's contacts carry current while the blade is closed.
Electrical isolator: A device that separates electrical equipment from its supply to provide isolation. Knife switches are used as isolating devices when their ratings and installation permit.
Disconnect switch: A switching device intended primarily to isolate a circuit from its electrical supply. Knife switches are one form of manually operated disconnecting device.
Electrical arc: A sustained electrical discharge through an ionized gas between conductors. High voltage or current can sustain an arc as the blade separates from a terminal.
Electrical insulation: Material or spacing that limits the passage of electric current. Insulation around the terminals and operating handle helps prevent unintended current paths.