ATOMIZER 3081906 - Caterpillar

Caterpillar Generator Set Engines that use heavy fuel oil have a control system with a strategy for derating the engine operation. This strategy reduces the engine load in order to help protect the engine from particular abnormal operating conditions. The strategy also notifies the operator of the condition. If the engine is allowed to continue with full load operation during an abnormal operating condition, engine damage could occur. If necessary, the strategy shuts off the engine. Normal engine operation can be resumed after the abnormal condition is corrected.The strategy helps to prevent operation in an unacceptable condition for an extended period of time. The strategy is in place in order to help protect your Caterpillar Engine investment.Definitions
Derating - The reduction of engine horsepower in response to an abnormal operating conditionRamped loading - An increase of the engine load over a period of timeRamped unloading - A decrease of the engine load over a period of timeContinuous rated output - The maximum allowable continuous engine operating speed or loadBase load - This is the continuous, controlled engine operating speed or load that is set by the operator. The range of the base load can be adjusted from a minimum up to the continuous rated output. The base load can be adjusted at any time. This includes operation during an alarm condition. The operator can reduce the base load if the engine cannot provide full power without operating in an alarm condition.Types of Derating
Different abnormal operating conditions have different potentials for causing damage. Some conditions can cause greater damage than other conditions. The potential abnormal operating conditions are classified by these three Types: 1, 2 and 3.Type 1 alarm conditions have complete priority over Type 2 and Type 3 conditions.Table 1 shows the types of derating, the parameters (abnormal operating conditions), and the setpoints which initiate the derating. The setpoint for derating the operation is equal to the setpoint of the alarm for each parameter.
Table 1
Derating for 3600 Series Generator Set Engines (Heavy Fuel Oil)
Type of Derating Parameter Setpoint
1 High exhaust port temperature deviation Difference of 50 °C (122 °F) from the average
1 High driveline torsional vibration Woodward 721 setpoint
2 High ACOC water temperature (inlet) 38 °C (100 °F)
2 High inlet manifold air temperature 70 °C (158 °F)
2 High inlet manifold air pressure 269 kPa (39 psi)
2 High lube oil temperature 92 °C (198 °F)
2 High jacket water outlet temperature 103 °C (217 °F)
2 Low sea water pressure (inlet) 172 kPa (25 psi)
2 High turbocharger speed 32,000 rpm
2 High generator stator temperature 155 °C (311 °F)
3 Lube oil centrifuge (alarm) No lube oil centrifuge Common Terminology and Procedures
The following terminology and general procedures are common to all three types of derating:
Operating parameters are monitored by a