Once the Majority of Power on Amtrak these Engines have certainly earned their keep for the Company. Some of these Engines have been around almost from the beginning of the Corporation some 25 years ago.
Many devices control the diesel locomotive. On the f-40 mainly its the Governor that controls the amount of fuel etc. to the Engine from instructions it gets from the cab control stand. Below is a list of the main components in the Engine Protection circuts.
Overspeed: a mechanical device located on the front of the Engine. If the engine speed exceeds the Engine limits this device shuts it down. It kind of works like a spring loaded cam; it reaches a certain RPM and centrifical force throws it out. A crew member easily resets the handle.
Hot oil detector: Detects a hot oil temperature above normal and takes appropriate action.
Engine Protective Device: On older systems this device was called a Paxton Mitchell, but the newer device does a lot more. Detects low water pressure due to malfunctioning water pump or clogged system. Engine crank case pressure; a bad cylinder or other malfunction causing excessive pressure in the crank case. Oil Pressure: detects no or low oil pressure due to possible clogged oil filters or other malfunction. Low or no water: detects low or no water in the system.
Fan and shutter switches: Four switches mounted on a water manifold that opens shutters, and up to 3 fans as the water temperature climbs. In a way this acts like a thermostate in your car. First at about 170 degrees it opens the shutters on the side of the Radiators near the rear of the engine. Progressively the fans come on as the temperature rises. Note: on newer designs, Engines run warmer, just as in modern automobiles.
Other Problems:
Engine hunting: An expression used to describe a Locomotive usually under full load in run 8, where the RPM fluctuates slightly, or severely and each time black smoke comes out the exhaust. Usally caused by dirty fuel filters or a suction leak in the fuel system.
Turbo Burping: A condition where the engine makes a loud burping sound and looses RPM with lots of black smoke. Usually caused by a dirty exhaust manifold screen or a bad turbo clutch.
Ground Fault Relay: A device in the control Cabinet of a locomotive that detects high voltage grounds,(traction Motor or any high voltage device), including the Dynamic Brake system. When a high number of Grounds are detected a Mechanic has to go through and diagnose the system in order to see where the ground is coming from. In a locomotive the low voltage system, 72 volts has both Positive and Negative connections. The Carbody and frame are neutral. On a low voltage ground, otherwise, it can be either Positive or Negative. Confused? so is everbody else!
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