ARMY TM 9-6115-672-14
AIR FORCE TO 35C2-3-444-32
MARINE CORPS TM 09244A/09245A-14
1-34
1.16.13.1.2 When the ENGINE CONTROL switch is first moved to the START position, the control modules are
energized. The Engine Starting System includes three control circuits. One starting control circuit energizes
the K2 relay through closed switch contacts of the crank disconnect relay. The second starting control circuit
signals the I/O interface module. With the K2 relay energized, power passes from the batteries through closed
contacts of the K2 relay to energize the starter solenoid. With the starter solenoid energized, power passes
from the starter solenoid to the cranking motor. The cranking motor then cranks the engine. Engine speed is
sensed by the magnetic pickup which sends a signal to the DCS speed control unit. As the engine accelerates
to approximately 900 RPM, the signal from the magnetic pickup causes the crank disconnect switch to open
the crank disconnect relay. The open contacts break the circuit to the cranking relay and stop engine cranking.
The third control circuit causes the field flash relay to be energized. When the ENGINE CONTROL switch is
moved to one of the two RUN positions, all starting control circuits are de-energized. The other generator set
control and instrument circuits remain energized.
1.16.13.1.3 The engine may be cranked without starting by use of the DEAD CRANK switch. With the DEAD CRANK
switch in the CRANK position, the K2 relay coil is energized to initiate engine cranking without energizing
any other starting or control functions.
1.16.13.1.4 The generator set can be started without batteries by connecting an external 24 VDC power source to the
NATO/SLAVE RECEPTACLE. The generator set can also supply power to another set through the
NATO/SLAVE RECEPTACLE.
1.16.13.1.5 The batteries are charged by the battery charging alternator which is belt driven by the engine. The CIM
display screen BATTERY CHARGE ammeter indicates the charge/discharge rate of the batteries, from -10
amps to +20 amps. A sensor provides a DC voltage signal, which is directly proportional to the actual battery
current flow, to the BATTERY CHARGE ammeter. Normal operating indication on the BATTERY
CHARGE ammeter depends on the state of the charge in the batteries. A low charge, which may exist
immediately after engine starting, will cause a high reading (indication toward CHARGE area). When the
charge in the batteries has been restored, the indicator moves near zero. The battery charging system is
protected from reverse polarity in the battery connections by a diode.
1.16.13.2
Field Flash. This circuit provides current to the exciter field windings which sets up an electromagnetic field.
The field current is necessary for the set to generate sufficient voltage for the automatic voltage regulator to
begin controlling the output voltage of the generator set. The field flash circuit is maintained until the
ENGINE CONTROL switch is released from the START position.
1.16.13.3
Operation. Placing the ENGINE CONTROL switch in the PRIME & RUN AUX FUEL positions keeps the
DCS speed control unit energized, and fuel will be supplied to the fuel injection pump as long as no fault
condition exists. During operation, the operator should periodically check the CIM display screen to ensure
readings are in normal operating ranges. The VOLTAGE ADJUST and FREQUENCY ADJUST switches are
adjusted as required to maintain desired frequency and voltage output.
1.16.13.4
Applying the Load. The load is applied by placing the AC CIRCUIT INTERRUPT switch in the CLOSED
position. This is a momentary contact switch that returns to the neutral, or center, position. The AC circuit
interrupter is energized by this momentary contact and a holding circuit keeps it closed, bringing the load on
line.
1.16.13.5
Shutdown.
1.16.13.5.1 The AC circuit interrupter is disengaged by placing the AC CIRCUIT INTERRUPT switch in the OPEN
position. This is a momentary contact switch which will break the AC circuit interrupter holding circuit and
then return to the neutral, or center, position, disconnecting the load from the line.
1.16.13.5.2 The generator set should remain running for five minutes after disconnecting the load. During this five minute
interval, oil circulates through the turbocharger, cooling it enough to be shut down.
