ARMY TM 9-6115-645-24
AIR FORCE TO 35C2-3-444-12
MARINE CORPS TM 09244A/09245A-24/2
1-12.2
1-12.2.1
1-12.2.2
Fuel System.
The Fuel System (FIGURE 1-3) includes a primary subsystem and an auxiliary subsystem.
The primary subsystem consists of fuel lines, fittings, fuel tank, low fuel level float switch, fuel float switch mod-
ule, fuel level sender, FUEL LEVEL indicator, transfer pump, fueI filter/water separator, injection pump and injectors. The
injection pump includes a 24 VDC fuel shutoff valve.
1-12.2.3 The injection pump output is controlled by the electronic govemor control and governor actuator. The electronic
governor control is energized, and the fuel shutoff valve in the injection pump is energized open whenever the MASTER
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 ener-
gized, 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. The 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 electronic governor con-
trol, and the fuel is shutoff whenever the MASTER SWITCH is turned to the OFF position. The electronic governor control
is also deenergized by the Fault System (refer to Paragraph 1-12.1.3). the FUEL LEVEL indicator displays the fuel level
of the fuel tank from E (empty) to F Full) in quarter tank increments.
1-12.2.4 The auxiliary subsystem consists of an auxiliary fuel supply, fuel lines, fittings, auxiliary fuel filter, auxiliary fuel
pump, auxiliary fuel pump float switch located in the fuel tank, and a fuel float switch module.
1-12.2.5 When the MASTER SWITCH is set on PRIME & RUN AUX FUEL, it actuates the auxiliary fuel pump and trans-
fers fuel from the auxiliary fuel supply to the fuel tank The auxiliary fuel pump float switch shuts off the auxiliary fuel pump
when the fuel tank is full and reactivates the pump as the level drops. The fuel float switch module allows the current used
by the auxiliary fuel pump to bypass the float switch.
1-12.2.6 The 24 VDC control circuits provide control and power for indicators, float switches, fault system, governor
control system, and auxiliary fuel pump.
1-12.3
Generator Set Cooling System.
1-12.3.1 The Generator Set Cooling System (FIGURE 1-4) 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.
1-12.3.2 Air is drawn in through the air intake grilles and forced through the engine coolant radiator and out of the genera-
tor set through the exhaust grille by the radiator cooling fan. Most of the cooling airflows 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.
1-12.4 Engine Cooling System.
1-12.4.1 The Engine Cooling System (FIGURE 1-5) consists of a radiator, hoses, thermostat, coolant temperature
sender, coolant high temperature switch, COOLANT TEMP indicator, water pump, oil cooler, cooling fan, and cooling jack-
ets (part of engine).
1-12.4.2 The water pump forces coolant through passages (cooling jackets) in the engine block and cylinder head where
the coolant absorbs heat from the engine. When the engine reaches normal operating temperature, the thermostat opens
and the heated coolant flows through the upper radiator hose assembly into the radiator. The cooling fan circulates air
through the radiator where the coolant temperature is reduced.
1-12.4.3 A coolant high temperature switch in conjunction with the fault system provides automatic shutdown in the
event that coolant temperature exceeds 225 ± 5°F (107 ± 3°F). The COOLANT TEMPERATURE indicator indicates the
engine coolant temperature, from 120°F to 240°F (48°C to 115°C).
1-12.4.4 The water pump also circulates coolant through the engine oil cooler to cool the engine oil.
Change 1 1-11
