How should emergency stopping be built, is pulling the throttle actuator to idle enough?
It is not enough. Emergency stopping is built by cutting the fuel, not by closing the throttle. Fuel shut-off solenoids come in two types: ETR (Energize To Run) cuts the fuel and stops the engine when power is removed, ETS (Energize To Stop) is energised in order to stop. The GS740 and GS740-3P have no emergency stop input; this chain must be built in the engine's own system.
The throttle actuator is not a stopping device. If the cable breaks, the clamp slips or the actuator jams, it cannot pull the throttle lever to idle. For that reason the safety chain is not based on the throttle side.
The correct arrangement:
- The emergency stop button directly breaks the fuel shut-off solenoid circuit. For safety the ETR type is preferred: if a wire breaks or power is lost, the engine stops.
- Engine protection switches (low oil pressure, high coolant temperature) are also connected into the same chain.
- In environments where there is a risk of diesel runaway, an automatic air shut-off valve is added to the intake manifold; in a runaway, cutting the fuel is not enough.
The GS740 and GS740-3P include none of these arrangements and do not replace them. The kit only drives the throttle lever position. During installation the emergency stop, engine protection and, where present, the air shut-off valve must be installed separately and independently.
Full topic: Electronic speed and throttle control on diesel engines