SECTION III. TECHNICAL PRINCIPLES OF OPERATION

ARMY TM 9-6115-673-13&P

AIR FORCE TO 35C2-3-512-1

SECTION III. TECHNICAL PRINCIPLES OF OPERATION

1.16.

INTRODUCTION.

1.16.1. This section contains functional descriptions of the generator set and explains how the controls and

indicators interact with the system.

1.17.

FUEL SYSTEM.

1.17.1. The Generator Set Fuel System (Figure 1-3) provides filtered and pressurized diesel fuel to the diesel

engine. It consists of a fuel tank with removable fuel fill strainer, fuel lines, fuel filter, fuel injection pump, and a fuel

injector.

1.17.2. The diesel fuel is stored in a fuel tank. The tank features a plastic mesh strainer in the fill neck opening

and a fuel tank drain valve. The fuel tank supplies fuel via a flexible tube to the fuel filter. The fuel filter

removes impurities and water from the diesel fuel before it reaches the diesel engine. The fuel filter is

made up of a clear bowl and filter head with a throw-away paper filter. The fuel filter also includes a fuel

hutoff valve and two bleed screws for removing air trapped in the fuel system. Another flexible tube

connects the fuel filter and the fuel injection pump (part of the diesel engine).

1.17.3. With the engine cranking or running, the fuel flow is controlled by a mechanical governor (part of the

diesel engine) and the fuel injection pump. The fuel injection pump pressurizes the fuel and transfers it to the fuel

injector (part of the diesel engine). Fuel is sprayed by the injector into the engine combustion chamber where it is

mixed with air and ignited. The fuel that is not burned by the engine is returned to the generator set fuel tank via an

excess fuel return line.

1.17.4. The diesel engine is shutdown by depressing the engine STOP lever which places the fuel injection pump

control rack in the no fuel position.

1.18.

ENGINE AIR INTAKE AND EXHAUST SYSTEM.

1.18.1. The Engine Air Intake and Exhaust System (Figure 1-4) provides filtered air to the diesel engine and an

outlet for exhaust gas produced by air/diesel fuel combustion. The system consists of an air intake filter, air intake

manifold, exhaust manifold, and muffler with spark arrester.

1.18.2 The air intake cleaner features a foam pre-filter and a disposable paper filter element. Air is drawn

through the pre-filter and the filter element. Airborne dirt is trapped in the pre-filter and air intake filter

element. Filtered air passes through the filter, air intake manifold, and open intake valve into the engine

combustion chamber where it mixes with pressurized diesel fuel and is combusted.

1.18.3. Immediately following combustion, hot gases are forced out of the combustion chamber (through the

open exhaust valve), and into the exhaust manifold. The exhaust manifold passes the gases into the

muffler which deadens the sound created by the combustion process. The gases then pass through the

uffler and out of the spark arrestor which diffuses the gas. A muffler shroud and blanket (wrapped

around the muffler), offer some protection to personnel who may inadvertently touch the muffler while the diesel engine

is running.