There are two types of prelubrication systems: continuous and intermittent.
The continuous prelubrication system is designed to run whenever the engine is not running. The following conditions must be met in order for the prelube pump to run:
- The engine is not running.
- Any active engine shutdowns are reset.
Therefore, only electric powered motors are used. The engine is modified so that oil can only rise to the top of the block. This is accomplished by using a dump valve that dumps excess oil back to the sump. This dump valve closes when engine oil pressure is sensed. When the engine is not running there is essentially no pressure that exists in this system. Therefore, an oil sensor "SODS" is used in order to detect lubrication in the engine. When the detector senses oil, the indicator lamp for the engine prelubrication will be illuminated.
The intermittent prelubrication system is designed to run before the engine is started. The following conditions must be met in order for the prelube pump to run:
- The engine is not running.
- Any active engine shutdowns are reset.
- The ECS is located in the LOCAL position or the REMOTE position.
If the ECS is located in the LOCAL position, the prelubrication switch must be located in the PRELUBE position. If the ECS is located in the REMOTE position, the automatic start/stop relay must be energized.
The system can use either an air motor or an electric motor in order to power the prelube pump. The system pumps the engine oil through the engine. Therefore, a pressure switch "SOPS" is used in order to detect the oil pressure. When the oil pressure in the main oil gallery of the engine reaches 9 kPa (1.3 psi), the indicator lamp for the engine prelubrication will be illuminated.
The engine can be started in two modes: local and remote.
The local mode indicates that the engine must be started from the engine control panel. The following conditions must be met in order to start the engine in the local mode.
- The engine control switch is located in the LOCAL position.
- The engine is prelubed.
- The fuel control switch is located in the ON position.
The engine can be started by holding the prelubrication switch in the START position. When the engine reaches 170 Rpm, the switch can be released.
The remote mode indicates that the engine can be started from a remote location by not using the engine control panel. The following conditions must be met in order to start the engine in the remote mode:
- The engine control switch is located in the REMOTE position.
- The fuel control switch is located in the ON position.
The engine can be started by actuating the customer supplied start switch. When the engine reaches 170 Rpm, the switch can be released.
Note: Refer to the engine Operation and Maintenance Manual for proper engine stopping procedure.
The engine will remain running until one of the following conditions are met:
- Emergency stop is activated.
- Normal stop is activated.
- Shutdown mode is initiated.
If an emergency stop is activated, the system will cause the governor actuator to shut off the fuel to the engine. The air shutoff at the intake of the engine will also be activated in order to shut off air supply to the engine.
Note: The engine control switch must be placed in the OFF/RESET position and the air shutoff must be manually reset before the engine can be restarted.
The engine is normally shut down in the following ways:
- In local mode, the fuel control switch is placed in the OFF position.
- In the remote mode, the customer supplied start/stop switch is used in order to de-energize the automatic start/stop relay.
When the conditions are met, the system will cause the governor actuator to shut off the fuel to the engine.
If a fault shutdown occurs, the system will cause the governor actuator to shut off the fuel to the engine. The fault must be corrected before the engine can be operated.
After the engine comes to a stop, the postlube cycle will begin. The postlube is used in order to lubricate the turbochargers by utilizing the prelubrication oil pumps. The lubrication will run for a period of time after the engine stops. In the event of an emergency stop, the postlube cycle will not cycle.
The ECP can be ordered with an annunciator. The annunciator is controlled by the programmable logic controller (PLC). When an alarm or shutdown condition exists, an input into the PLC will go high. This will cause the output that is associated with the input to start flashing an indicator and an output from the PLC will energize the horn relay. The output will continue to flash until the "Acknowledge/Lamp Test" switch is momentarily switched to the Acknowledge position. The output will then remain illuminated and the horn relay will be de-energized. Once the alarm or shutdown condition has been cleared, pushing the reset button will cause the outputs of the PLC to shut off.
When the "Acknowledge/Lamp Test" switch is held in the Lamp Test position, the outputs of the PLC will be active. This will illuminate all the lights of the annunciator and the horn relay.