ECON-4 1.4.0 Global Guide
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5.6 Detailed fucntion
5.6.1 Block schematics - speed governor
Overspeed protection in ECON4-ADV
Instead of value in the middle between Nominal and Overspeed there is additional RPM level defined in setpoint
Engine RPM: PreOverSpeed in ECON4-ADV versions. When RPM reaches this level, Gas Dose Value
(throttle position) goes to value in setpoint Engine RPM: PreOverSpReduct – can be set to Idle Fuel or Close.
This feature was added to prevent overspeed when Load is removed – typically switch off large load in island
operation.
Overspeed protection
In case the actual RPM crosses RPM value: Engine RPM: Overspeed, then the Gas Dose is immediately
forced to the zero – throttle is closed and shutdown is issued.
There is proactive action taken to try to keep engine running without shutdown, when actual RPM reaches value
in the middle between Nominal and Overspeed value. In this case, when RPM crosses this middle value, Gas
Dose is set to Idle position and when RPM drops back below this middle value, speed PID will continue to
regulate RPM.
Purpose of this behavior is to prevent the Overspeed situation by detecting the RPM increase and step change
of the fuel (closing the fuel). As the RPM are dropping down subsequently towards the Nominal RPM the fuel is
