Series 50 – Section 8.2 Overview of Electrical System for Series 50G Engine

Section 8.2
Overview of Electrical System for Series 50G Engine

The Series 50G is Detroit Diesel's first spark-ignited engine. Detroit Diesel's ignition system consists of DDEC III, ignition coils, spark plugs, and wires. DDEC controls the spark.‪

The Series 50G spark ignited high pressure gas engine utilizes the Detroit Diesel Electronic Control (DDEC) system in conjunction with the Gaseous Fuel Injection (GFI) system, specifically tailored for the Series 50 gas engine, to control combustion. The GFI computerized fuel injection system electronically meters fuel according to demand. A combination of Detroit Diesel and GFI sensors are used to dynamically monitor the engine and environment to provide open loop fueling. In addition to assisting with fuel delivery control, DDEC is used to control the spark ignition system, provide engine shutdown protection, and provide additional safety shut downs for the vehicle fuel system. The DDEC system has been modified to provide optimum operation for the Series 50G engine. The Series 50G electronic control system includes the following enhancements:‪

• The low pressure system controls both spark for the spark plugs and fuel delivery.
• The ECM has been modified for use with the Series 50G. A standard diesel ECM cannot be used with the Series 50G.
• The Series 50G has been modified to incorporate additional engine sensors including:
  • Inlet Air Temperature (used in conjunction with GFI system)
  • Oil Temperature (used in conjunction with GFI system)
  • Knock Sensor
  • Manifold Air Pressure (MAP)
  • Barometric Air Pressure (BAP)
  • Fuel Pressure
  • Fuel Temperature
• The Series 50G design incorporates certain gas components including:
  • Signal Noise Enhancement Filter (SNEF) Module