Inertia safety switch

INERTIA SAFETY SWITCH

Foreword

This switch is located alongside the driver’s seat on the left hand side and triggered in the case of vehicle collision to cut off the earth connection to the fuel pump and thus the supply to the injection system.

Principle of operation

A steel ball fitted inside a tapered housing is normally held in locked position through the attractive force of an adjacent magnet. In the case of specific acceleration loads, the ball is released from the magnetic attraction and gradually emerges from the tapered mount, following an upward movement according to cone angle.

A quick-release mechanism above the ball makes up a normally closed (N.C.) electrical circuit. When the mechanism is struck by the ball, it changes position from an N.C. circuit to a normally open circuit (N.A.) and thus breaks the fuel pump earth circuit.

In the case of a collision in any one the three orthogonal directions, the switch will operate at a peak value of over 12 g equivalent to a speed of about 25 Km/h.

The switch may be reset by pushing the button protected by a flexible cover (used also to protect against foreign bodies that could impede operation or cause reprogramming to occur).

After even an apparently light collision, if a smell of petrol is noted or fuel leaks are seen, do not activate the switch again until the fault has been found and corrected in order to avoid the risk of fire.

If no leaks are noted and the vehicle is able to start, press the button to re-activate the pump.