MTU 12 V 2000 P12 Operating Instructions Manual page 31

Switching to an external speed setting takes place automatically once the nominal speed has been
reached.
The following speed setting variants are possible:
• Desired speed setting via an analog input:
The setpoint speed can be adjusted within a (configurable) range around the preset synchronous
speed (depending on the set network frequency).
In this case the voltage can either control the speed window only or cover the entire speed range.
The internal setpoint speed follows the applied speed setting value along a configurable acceleration/
deceleration curve (speed ramp). The setting value last applied is maintained or the engine is throttled
back to idling speed should the applied signal fail.
The response can be configured as desired:
• Speed setting via CAN bus.
• Speed setting via an analog speed setting input (0 V to 10 V).
• Speed setting via an analog speed setting input (4 mA to 20 mA).
• Frequency input.
• Setpoint processing via binary inputs "Setpoint speed up" (BE5)/ "Setpoint speed down" (BE6):
The setpoint speed can be adjusted within a (configurable) range around the preset synchronous
speed (depending on the set network frequency). Briefly actuating the appropriate optocoupler input
for less than 0.3 s increases or decreases the setpoint speed by 1 rpm.
The setpoint speed is automatically adjusted at a configurable rate if the input is activated for longer
than 0.3 seconds.
Safety functions
Safety shutdowns
Safety shutdowns are initiated by the engine protection system in case of:
• Limit value violations;
• Sensor faults (depending of specific configuration).
This applies to the following measuring points:
• Engine speed/overspeed (configurable)
• Engine lube oil pressure (configurable)
• Coolant level (configurable)
• Charge-air coolant temperature (configurable)
• Coolant temperature (configurable)
• Charge-air temperature (configurable)
• Engine lube oil temperature (configurable)
All safety shutdowns can be suppressed by activating the "Override" input (BE8, default).
The occurrence of safety-relevant alarms is still logged when the "Override" input has been activated.
Fault number 500 is added to the current fault number.
Integral Test System (ITS)
The ITS monitors all important functions of the engine governor and connected electrical components:
• Electronics inside the engine governor itself,
• sensors,
• actuators,
• bus communication,
• power supply.
The ITS detects any faults which occur, pinpoints them and signals accordingly by combined alarms.
Furthermore, a fault message is output via the CAN bus to a higher-level monitoring system (if applica‐
ble) and can visualized there for the operator.
MS150025/02E 2012-10 | General Information | 31