Emergency Stop Chain
The independent line, running from the button to the stopping element, that reliably stops the engine in a hazardous situation. Stopping is built by cutting the fuel or the air, not by closing the throttle. Pulling the throttle actuator to idle does not count as stopping; a broken cable or a seized joint can invalidate that path.
The design rule of the chain is that a single fault must not prevent stopping. For that reason the path is built independently of the throttle control and, where possible, designed to stop the engine when power is removed. An ETR type fuel shut-off solenoid does exactly this: when power is cut, fuel is cut.
A typical chain consists of these elements:
- An easily reachable, latching emergency stop button.
- A fuel shut-off solenoid or a mechanical fuel shut-off lever.
- An air shut-off valve fitted in the intake path if there is a runaway risk.
- If required, connecting the engine protection switches into the same line.
In the GS740 and GS740-3P documentation no emergency stop input is declared. These kits are devices that drive the position of the throttle lever; they do not take on a stopping function. If there is to be an emergency stop button on the panel, its wiring must go directly to the fuel shut-off chain, not to the speed control system.
Context in which this term is used: Electronic speed and throttle control on diesel engines