ARMY TM 9-6115-671-14
AIR FORCE TO 35C2-3-446-32
MARINE CORPS TM 09249A/09246A-14A
1-22
1.16.5.3
The injection pump output is controlled by the DCS speed control unit and electric actuator. The DCS
speed control unit is energized whenever the ENGINE CONTROL switch is in the START position or
either of the two RUN positions. With the engine cranking or running, fuel is drawn from the fuel tank
by the transfer pump. After reaching the transfer pump, fuel passes through a fuel filter/water separator
where water and small impurities are removed. The fuel then goes to the injection pump. With the
governor system energized, the fuel is metered, pressurized and pushed through the injectors by the
injection pump. Fuel is sprayed by the injectors into the diesel engine combustion chambers where it is
mixed with air and ignited. Fuel that is not used by the injectors is returned to the fuel tank by an
excess fuel return line. Power is removed from the DCS speed control unit, and the fuel is shut off
whenever the ENGINE CONTROL switch is set to the OFF position. The DCS speed control unit is
also de-energized by the fault system, paragraph 1.14.2. The CIM display screen FUEL LEVEL
indicator displays the fuel level of the fuel tank from E (empty) to F (full) expressed as percent
remaining.
1.16.5.4
The auxiliary subsystem consists of an auxiliary fuel supply, fuel lines, fittings, and an auxiliary fuel
pump.
1.16.5.5
When the ENGINE CONTROL switch is set on PRIME & RUN AUX FUEL, it actuates the auxiliary
fuel pump and transfers fuel from the auxiliary fuel supply to the fuel tank. The CIM shuts off the
auxiliary fuel pump when the fuel tank is full and reactivates the pump as the level drops.
1.16.5.6
The 24 VDC control circuits provide control and power for indicators, fault system, DCS, and auxiliary
fuel pump.
1.16.6
Mechanical System.
1.16.6.1
The mechanical system provides protection from the elements, structural integrity, transportability,
noise suppression, and the cooling system for the generator set. The generator set cooling system is
described separately below.
1.16.6.2
The mechanical system consists of the housing, insulation, air baffles, and skid base.
1.16.6.3
The generator set housing is insulated to provide "tactical quiet" noise suppression which makes
detection of the generator set by it's audio signature more difficult under battle conditions. Air baffles
allow for airflow to cool the generator set with as little impact as possible to the generator set's noise
output.
1.16.6.4
The skid base provides a stable base for the generator set during operation and transport, and allows the
generator set to be moved by forklift or mounted on a trailer.
1.16.7
Generator Set Cooling System.
1.16.7.1
The Generator Set Cooling System (Figure 1-23) includes air intake and exhaust grilles, baffles, and
ducting within the generator set housing and the engine driven radiator cooling fan. The air intake
grilles are located in panels on both sides of the generator set housing. The air exhaust grille is located
in the housing top panel.
1.16.7.2
Air is drawn in through the air intake grilles and forced through the engine coolant radiator and out of
the generator set through the exhaust grille by the radiator cooling fan. Most of the cooling air flows
externally past the generator assembly and engine. Some cooling air is circulated internally through the
generator assembly by a generator fan which is an integral part of the AC generator assembly. Baffles,
ducting, and sound absorbing material are used to control the air flow through the generator set and to
reduce sound transmission through the grilles.
