Inertia Fuel Shutoff Switch: Description and Operation

Typical Inertia Fuel Shut-Off Switch:

The inertia switch is used to open the power circuit to the fuel pump, or the control circuit to the fuel pump relay, in case of an accident. The inertia switch must be manually reset by pushing the reset button located on top of the inertia switch.

Operation of the inertia switch is as follows:

A steel ball is held in place by a magnet. When a sharp impact occurs, the ball breaks loose from the magnet, rolls up a conical ramp and strikes a target plate, which opens the electrical contacts.