3855907 Volvo.Penta Lower gear, complete

Illustration 1 g01019009Cat ET - This software is designed to run on a personal computer. Technicians can use the program to perform many functions. For the air/fuel ratio control, the technician programs configuration parameters into the ECM.Inlet manifold temperature sensor - This sensor monitors the temperature of the air/fuel mixture in the air inlet manifold.Inlet manifold pressure sensor - This sensor monitors the pressure of the air/fuel mixture in the air inlet manifold.Engine speed/timing sensor - This sensor monitors the rotation of a speed-timing wheel in order to provide information on the engine timing and on the engine rpm.Wattmeter - The engine's control system requires an input which indicates the generator's output in kilowatts. This input can be from the following components: EMCP II+, programmable logic controller (PLC) and wattmeter. The equipment that monitors the generator's output is provided by the customer if the EMCP II+ is not used. The PLC or the wattmeter must provide an analog signal within the range of 0 to 5 volts. The output must have a linear relationship with the generator's actual output in electrical kilowatts (ekW). The output must be accurate within 0.5 percent of the generator's actual current. The out put must use as much the acceptable range as possible.Fuel metering valve - This is an electronically controlled actuator and a valve that regulates the flow of fuel. The device monitors the fuel temperature, the fuel pressure, and the valve's differential pressure. The ECM sends a command signal for the fuel flow to the device. The device modulates the valve in order to match the command signal.The ECM communicates with the fuel metering valve via the CAN Data Link.The air/fuel ratio control has two basic modes of operation:
Open loop
Charge density feedbackThe modes of operation are explained below.For proper operation of the air/fuel ratio control, input from the customer is necessary.Input from the Customer
To accurately control the air/fuel ratio, the control system depends on input from the customer.Before the initial start-up, a current gas analysis is required. Data from the gas analysis must be entered into Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)". The results are programmed into the ECM.Note: It is very important to use the Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)". Use of only the data from the gas analysis can result in incorrect settings.The following parameters are programmed into the ECM via the "Configuration" screen of Cat ET:
"Fuel Quality"
"Gas Specific Gravity"
"Fuel Specific Heat Ratio"
Four inputs for the engine loadNote: For more details on these topics, refer to Systems Operation/Testing and Adjusting, "Electronic Control System Parameters"."Fuel Quality" - This is the fuel's Low Heating Value (LHV). The value is obtained from a fuel analysis which is entered into Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)".During operation, the ECM uses the LHV to help determine the command signal for the fuel flow."Gas Specific Gravity" - This is the fuel's specific gravity in relation to the specific gravity of air. The value is obtained from a fuel analysis which is entered into Caterpillar Software, LERW4485, "Gas Engine Rating Pro (GERP)"."Fuel Specific Heat Ratio" - This is a ratio of the fuel's specific heat at a constant pressure and at a constant volume.The ECM provides the fuel's specific gravity and heat ratio to the fuel metering valve via the CAN data link. The fuel metering valve uses this information to help regulate the fuel flow.In addition to the information on the fuel, the ECM requires information on the engine load.Engine Load
The ECM must have values for the following parameters. The parameters are entered into the ECM via Cat ET.
"Engine Output Power Configuration"
"Engine Driven Accessory Load Configuration"
"Generator Output Power Sensor Scale Factor"
"Generator Output Power Sensor Offset""Engine Output Power Configuration" - This is the engine's full load rating in ekW. The rating is stamped on the engine's Information Plate."Engine Driven Accessory Load Configuration" - This is the load of the auxiliary equipment such as a radiator fan that is directly driven by the engine."Generator Output Power Sensor Scale Factor" - This is a scale for the wattmeter's output.If the generator is equipped with the EMCP II+, information on the generator's electrical power output is provided to the ECM via the CAT data link. The ECM is correctly programmed at the factory for the "Generator Output Power Sensor Scale Factor" and the "Generator Output Power Sensor Offset" parameters. No further adjustment is necessary for the parameters.If the generator is not equipped with the EMCP II+, information on the engine load must be provided by a customer supplied wattmeter. The wattmeter's output to the ECM must be an analog signal within the range of 0 to 5 volts. A voltage that is near 0.2 VDC indicates that the generator has a low power output. A voltage that is near 4.8 VDC indicates that the generator has a high power output.Because there are different wattmeters, the scale for the wattmeter's output must be entered into the ECM. The scale provides a linear relationship between the wattmeter's voltage output and the generator's electrical power output. The scale corresponds to the wattmeter's output."Generator Output Power Sensor Offset" - The offset is used to make the wattmeter's scale accurate.Because the output from different wattmeters can vary, an offset for the wattmeter must also be entered into the ECM. The offset can be a positive value or a negative value.All of the above parameters are programmed into the ECM via the "Configuration" screen of Cat ET. For more details, refer to Systems Operation/Testing and Adjusting, "Electronic Control System Parameters".Open Loop Mode
Open loop - During operation in this mode, the ECM controls the air/fuel ratio with maps and with calculations for the desired air/fuel ratio. This mode of operation uses no feedback. The air/fuel ratio is controlled in the open loop mode from start-up until the engine load becomes greater than 25 percent.The ECM uses a Fuel Correction Factor (FCF) to help determine the fuel flow. During operation in the open loop mode, the FCF is always 1. This