ARMY TM 9-6115-672-14
AIR FORCE TO 35C2-3-444-32
MARINE CORPS TM 09244A/09245A-14
TABLE 2-4. DIAGNOSTIC CONTROLS AND INDICATORS (continued)
CONTROL OR INDICATOR
SPEED CONTROL UNIT
OVERSPEED indicator (red LED)
This indicator is normally off, even when the generator set is
operating. When the LED is lit, an engine overspeed condition
has occurred (the flywheel RPM sensor has sent the speed
control unit a value which is defined as out-of-tolerance). The
indicator will remain lit until either of two events has occurred:
(1) The OVERSPEED RESET pushbutton has been manually
activated, or (2) the generator set (engine) has been stopped and
the DC power is reset.
ACTUATOR indicator (green
This indicator is normally lit when the electric actuator (on the
injection fuel pump) has power applied to it. The LED will be
lit when the engine is operating or when the engine is being
cranked (started). If the indicator is off while the engine is
operating, it can mean: (1) the electric actuator has failed, (2)
the connection between the actuator and the module has failed,
or (3) the module has malfunctioned or failed.
SPEED SENSOR indicator (green
This indicator is normally lit when the engine is operating. The
indicator lit/off function is directly related to the signal from the
speed sensor connected to the flywheel. If the indicator is off,
but the engine is operating, this indicates the engine RPM
signal is not being received. This can be caused by sensor
failure or by a failure in the connection to the sensor.
OVERSPEED RESET pushbutton
If the OVERSPEED indicator is lit and the engine has stopped,
this switch may be used to attempt to reset the overspeed
protection system. If the OVERSPEED indicator turns off
when the switch is activated, the protection system is reset, and
the engine may be restarted. (The conclusion is that no
problem exists with engine speed.) If after restarting the
OVERSPEED indicator comes on again and the engine stops,
there is a problem with engine speed control.
OVERSPEED TEST pushbutton
This switch is used to test one of the protective systems of the
generator set: engine overspeed protection. Pressing this
switch while the engine is running at rated speed will activate
the overspeed protection system, thereby stopping the engine.
DC POWER indicator (green
This indicator is normally lit when the engine is operating. It
indicates the internal DC power in the module is operating.
CRANK TERMINATION (green
This indicator is normally lit when the engine is operating.
When the engine is being started, the indicator will remain off
until engine speed exceeds 400 RPM and the cranking relay
returns to its normal (non-energized) state. If the indicator
remains off and the engine starter continues operation, this is an
indication of a failure in the starter assembly or of the cranking
LED 16 (red) indicator
LED 15 (red) indicator
LED 14 (red) indicator
Fault indication. If indicator is lit, indicates a fault has
occurred. If off, indicates normal running condition.