ARMY TM 9-6115-671-14
AIR FORCE TO 35C2-3-446-32
MARINE CORPS TM 09249A/09246A-14A
1-18
1.16.2.2
The Fault System consists of the CIM, I/O interface module, fuel level sender, oil pressure sender,
coolant temperature sender, and BATTLE SHORT switch.
1.16.2.3
Inappropriate signals received from the senders by the I/O interface module will cause the CIM to
display the fault, and a message describing the condition causing the fault, on the CIM display screen.
Depending on the nature of the fault, the generator set will shut down or the operator will be warned
that action must be taken to avoid shutdown.
1.16.2.4
Activation of the fault system will cause two events to occur. The AC interrupter relay will open and
CONTACTOR POSITION status indicator on CIM display screen will indicate OPEN.
1.16.2.5
Although it is possible for more than one fault to occur at one time during operation, and for more than
one fault to be displayed on the CIM display screen at a time, only the first fault to occur will cause a
message to appear in the MESSAGES display area of the CIM display screen. Once the condition
addressed in that message has been corrected by the operator, the operator will activate the FAULT
RESET switch, and the next message will be displayed.
1.16.2.6
After the generator set engine has been started, the BATTLE SHORT switch may be used to override
all potential faults except engine overspeed and short circuit.
1.16.3
Governor Control System.
1.16.3.1
The governor control system (Figure 1-20) includes the DCS speed control unit, electric actuator, DCS
load sharing synchronizer, magnetic pickup, fuel injection pump, and FREQUENCY SELECT switch.
1.16.3.2
The electric actuator controls the output of the fuel injection pump in response to the electrical input
from the DCS speed control unit. The DCS provides a signal representing the desired engine
speed/generator frequency to the DCS speed control unit. A signal representative of the actual engine
speed/generator frequency is sent to the DCS speed control unit by the magnetic pickup. Any change
in engine speed from that selected by the operator, as sensed by the magnetic pickup, causes the DCS
speed control unit to increase or decrease fuel injection pump output to maintain the desired speed.
Generator set frequency and power output are indicated on the CIM display screen. The
FREQUENCY SELECT switch is used to set the generator for 50 hertz or 60 hertz operating
frequencies (MEP-805B only).
1.16.3.3
Twenty-four VDC power is supplied to the DCS speed control unit through the governor control power
relay. The governor control power relay is controlled by the fault system. The DCS speed control
units of two generator sets operating in parallel are interconnected by the paralleling cable.
1.16.4
Voltage Regulation System.
The Voltage Regulation System (Figure 1-21) consists of the automatic voltage regulator and power
potential transformer. The automatic voltage regulator senses and controls generator output voltage
which is operator adjustable within the design limits by use of the VOLTAGE ADJUST switch. The
power potential transformer provides operating power to the automatic voltage regulator module.
Generator output voltage is indicated on the CIM display screen.
1.16.5
Fuel System.
1.16.5.1
The Fuel System (Figure 1-22) includes a primary subsystem and an auxiliary subsystem.
1.16.5.2
The primary subsystem consists of fuel lines, fittings, fuel tank, fuel level sender, transfer pump, fuel
filter/water separator, injection pump, DCS speed control unit, and injectors. The injection pump
includes a 24 VDC fuel shutoff valve.
