The relay contacts (SPDT) are intended to be used to shut the engine off. Connect these contacts to your motor controller or ignition controller. Directly switching the ignition coil primary winding is not permitted because it generates strong EMI emissions which may lead to On-Board Computer malfunction.
Installing the normally closed (NC) relay contacts of the relay in series with the primary of the ignition coil will achieve the desired results. As an option, the NC relay contact could be wired in series with the fuel injector to achieve the same results.
For Diesel engines, installing the NC relay contacts in series with a fuel shutoff solenoid or in series with the fuel injector will kill the engine when the relay is activated.
Before the event, teams should identify the circuit that will be wired through the shutdown relay.
IT IS REQUIRED TO CONNECT THE SHUTDOWN RELAY DIRECTLY TO THE ECU, RATHER THAN TO THE IGNITION COIL DUE TO EMI PROBLEMS
The shutdown relay must disable vehihle propulsion when the relay is activated. Connections can be made from N to NC (Normally Closed, will open when relay is activated) or from N to NO (Normally Open, will close when relay is activated) depending on system configuration. Maximum relay current = 10 amps.
Other methods will be accepted as long as the drive system is disabled when the relay is activated
Shutdown Relay Connection Examples