17442 Mariner COVER

Diesel Engine Panel
Engine Supervisory System Functional DiagramElectronic Panel Description
The Engine Supervisory System is a microprocessor based system designed to provide superior monitoring and control for Caterpillar engines.Electronic sensors are used to monitor engine functions. The electronic gauge modules display this information and provide customer-defined alarms and shutdowns for these functions. The control logic provides prelubing and cranking features as well as manual emergency stop operation.The Engine Supervisory System may operate in either the Energize-to-Run (ETR) or the Energized-to-Shutdown (ETS) mode.In the ETR mode, the engine will shutdown if control power is lost. In the ETS mode, the engine will continue to run if control power is lost. Changing the operating mode involves moving a jumper in the panel, changing a flag value within the electronic modules, and installing a different Electronic Governor Fuel Shutoff Solenoid (EGFSOS).The Engine Supervisory System Functional Diagram shows the general flow of signals between the various components of the control system.Operation of the Sensors
There are three types of sensors used to monitor the engine:* Contact Switches* Magnetic Pick-up Units (MPU)* Ratiometric Electronic SensorsThe contact switches provide the switch inputs to the control module. They may include level switches, solid state switches, or relay contacts.The magnetic pick-up units are the same units used on other Caterpillar engines. They provide an alternating current signal whose frequency is the product of the engine's revolutions per second times the number of gear teeth on the flywheel where the unit is mounted.The ratiometric electronic sensors act as a function controlled voltage divider. Electrically, they perform like a variable resistor as shown below.
FUNCTIONAL DIAGRAM OF SENSORThe electronic gauge modules provide a supply voltage (VS) to the sensors. The signal (SIG) is a fraction of the supply voltage. Example:Consider a temperature sensor. Changes in temperature functionally cause the position of the "wiper" to change. The electronic gauge module compares the ratio of the signal voltage to the supply voltage.Therefore, slight fluctuations in the power supplied to the sensor have no effect on the accuracy of the reading. The ratio of the signal voltage compared to the supply voltage is converted to a temperature value in Fahrenheit (°F) or Celsius (°C) by the electronic gauge module.Operation of Electronic Gauge Modules
The electronic gauge modules monitor the engine using the sensors described previously. Each module has a liquid crystal display (LCD) which can be used to display the signal received from a sensor.The lower portion of each module contains three touch buttons. The engine or auxiliary equipment function being displayed is identified by the "carrot" (black triangular pointer) directly above the ISO symbol of the function being displayed. To view a function, press the center of the button with the ISO symbol for that function. If more than one symbol is on a button, press the same button a second or third time until the "carrot" points to the desired symbol on the button.When the electronic gauge modules sense that the engine is running, continuity exists between the engine running terminal and the battery minus (-) terminal on module 1.If an alarm occurs, the module signals this by causing the display to flash and change to the highest priority sensor whose value caused the alarm. In addition, the module also provides continuity between the alarm horn signal connection and the battery minus (-) terminal, causing the alarm horn to sound.If a shutdown occurs, the modules display will alternate between "ES" engine shutdown and the value of the function that caused the shutdown. If the electronic control module is set for ETS mode, then continuity between the fuel shutoff terminal and battery minus is provided when fuel is to be shut off.If the module is set for ETR mode, continuity is not provided between the fuel shutoff terminal and battery minus when the fuel is to be shut off. In addition, if the shutdown is caused by an engine overspeed, continuity is also provided between the air shutdown terminal and battery minus (-).Operation of the Junction Box Logic
The junction box logic uses signals from the electronic gauge modules and manual inputs to control the supply of fuel and air to the engine. It turns on and off the Electronic Governor Fuel Shutoff Solenoid (EGFSOS), Air Shutoff Solenoid (ASOS), Air Prelube Solenoid Valve (APSV), and the Air Start Solenoid Valve (ASSV). The following topics describe these tasks in more detail.Engine Control Switch
OFF\RESET Position
This is the position where the Engine Control Switch (ECS) should be left when the engine will be shut down for long periods of time. Power to the electronic gauge modules, junction box logic and engine solenoids is removed.If the engine shuts down due to a fault condition, turning the ECS to this position will clear the system and allow the engine to be restarted if the fault has been remedied.STOP Position
This is the position where the Engine Control Switch (ECS) should be placed to manually stop the engine. Power to the electronic gauge modules is provided, so the user may monitor engine functions.If the engine mode is ETS and the engine is running, power is provided to energize the EGFSOS, which cuts off the supply of fuel to the engine. Once the electronic gauge modules sense that the engine is no longer running, power is removed from the EGFSOS.If the engine is being operated in the ETR mode, turning the ECS to the STOP position removes power from the EGFSOS, thereby removing the source of fuel to the engine.While the ECS is in the STOP position, the engine can be prelubed and/or cranked without starting.Crank/Prelube Switch
To prelube, the CRANK/PRELUBE switch should be placed in the PRELUBE position. This causes the intermittent prelube system to be energized. When lube oil is sufficient to crank the engine, the Starting Oil Pressure Light (SOPL) will illuminate.To crank the engine without starting, the CRANK/PRELUBE switch should be held in the CRANK position. The APSV will be energized whenever the switch is held in the CRANK position. If sufficient lube oil to crank is not present, no cranking