ARMY TM 9-6115-642-24
AIR FORCE TO 35C2-3-455-12
MARINE CORPS TM 09247A/09248A-24/2
1-12.8.5 Shutdown.
1-12.8.5.1
The AC circuit interrupter relay is disengaged by placing the AC CIRCUIT INTERRUPTER switch in the
OPEN position. This is a momentary contact switch which will break the AC circuit interrupter relay holding circuit and
then return to the neutral, or center position, disconnecting the load from the line.
1-12.8.5.2
When the MASTER SWITCH is placed in the OFF position, all power is removed from the control circuit
and the engine will stop.
1-12.8.5.3
The EMERGENCY STOP switch will remove power from the control circuit by energizing the engine fault
relay. This will cause the engine to shut down. The EMERGENCY STOP switch is not to be used as an alternative for
routine shutdown procedures. When the generator set is stopped using the EMERGENCY STOP switch, some circuits
remain energized causing a drain on the batteries until the MASTER SWITCH is placed in the OFF position.
1-12.9 Governor Control System.
1-12.9.1
The Governor Control System (FIGURE 1-10) includes the FREQUENCY ADJUST control, mechanical en-
gine governor, engine fuel pump rack, and fuel solenoid.
1-12.9.2
The mechanical engine governor is housed under the engine gear cover and moves the fuel pump rack,
changing fuel delivery of the injection pumps in proportion to engine load. The governor is a flyweight type, with the
weights mounted on the engine camshaft gear. The force of the flyweights is transferred through a thrust sleeve and
collar to the governor lever, and balanced against the tension of the governor spring, which is stretched between the
governor lever and the speed adjustment lever. Engine speed and generator output frequency are increased by increas-
ing the tension on the main governor spring. Droop is adjusted by varying the location of the governor spring’s mounting
to the governor lever, effectively varying the strength of the spring.
1-12.9.3
The governor uses one lever for fuel shutoff and the other for speed adjustment. The shutoff lever is operated
by the fuel solenoid in an energize-to-run configuration (fail safe). The speed adjustment lever is moved by a vernier
control cable from the FREQUENCY ADJUST control of the set and provides an adjustment range of + 3 percent of rated
frequency at rated load.
1-12.10 Voltage Regulation System.
The Voltage Regulation System (FIGURE 1-11) consists of the voltage regulator and VOLTAGE adjust potentiome-
ter. The voltage regulator senses and controls the generator output voltage which is operator adjustable within the design
limits by use of the VOLTAGE adjust potentiometer. The output voltage to the load is indicated by the AC voltmeter
(VOLTS AC) on the control panel assembly.
1-13
LOCATION AND DESCRIPTION OF MAJOR COMPONENTS.
NOTE
All locations (FIGURE 1-12) referenced herein are given facing the control box side
(rear) of the generator set.
1-13.1
Oil Filter (1). The oil filter is located in the engine compartment on the left side. The filter removes impurities
from the engine lubricating oil.
1-13.2
Dipstick (2). The dipstick is located in the engine compartment on the left side. The dipstick shows the lubricat-
ing oil level in the engine crankcase.
1-13.3
Fuel Filter/Water Separator (3). The fuel filter/water separator is located to the rear of the engine compartment
on the left side. The element removes impurities and water from the diesel fuel.
1-13.4
AC Generator (4). The AC generator is a single bearing, drip-proof, synchronous, brushless, three phase, fan-
cooled generator. The generator is coupled directly to the rear of the diesel engine.
1-13.5
DEAD CRANK Switch (5). The DEAD CRANK switch is located in the engine compartment on the left side.
For maintenance purposes the switch allows the engine to be cranked without starting.
1-13.6
Engine (6). The generator is powered by a four cylinder, four cycle, fuel injected, naturally-aspirated, liquid-
cooled diesel engine which occupies the front half of the generator set. The engine is also equipped with a fuel filter/water
separator, oil filter, and an air cleaner assembly. Protection devices automatically stop the engine during conditions of
high coolant temperature, low oil pressure, no fuel, and overvoltage.
1-20 Change 2
