TM 9--2350--292--20--1
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MONITORING SYSTEM OVERVIEW AND DIAGRAMS.
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THIS WORK PACKAGE COVERS:
Monitoring System Overview and Diagrams
The monitoring system includes electrical circuits for the generator output and battery system indicator, main en-
gine gauges and indicators, transmission gauges and indicators, and hydraulic system gauges and indicators.
The generator output and battery system indicator circuits consists of the ENGINE BATT/GEN VOLTS gauge,
15--amp circuit breaker, and related electrical wiring. When the MASTER switch is ON, the ENGINE BATT/GEN
VOLTS gauge displays the status of the vehicle system power source. When neither the main engine nor APU en-
gine is running, the gauge indicates the condition of the batteries based on the voltage measured (nominally +24 V
dc). If either the main engine or APU engine is in operation, the gauge indicates the status of the applicable gener-
ator output again based on the voltage measured (nominally +28 V dc). The gauge will also indicate the status of
an external power source, if applicable. The system power source, regardless of the origin, is applied from the
master relay through the 15--amp circuit breaker in the switch panel to the ENGINE BATT/GEN VOLT gauge. The
gauge is grounded on the gauge panel completing the circuit to provide the status indication (voltage measure-
ment).
The main engine gauges and indicators circuit include the ENGINE TEMP gauge (engine oil temperature), EN-
GINE PRESS gauge (engine oil pressure), FUEL TANK LEVEL gauge, TURBO DUST DET indicator (turbocharger
dust detector), FUEL TANK FRONT/REAR selector switch, two liquid level transmitters, engine oil temperature
transmitter, engine oil pressure transmitter, two dust detector pressure switches, 15--amp circuit breaker, and re-
lated electrical wiring.
The engine oil pressure gauge operates whenever the main engine is running and provides an indication of current
engine oil pressure. The oil temperature and FUEL TANK LEVEL gauges together with the turbocharger dust de-
tector indicator operate anytime the MASTER switch is turned ON. The engine oil temperature gauge provides an
indication of current engine oil temperature. The FUEL TANK LEVEL gauge indicates the level of fuel in either the
front or rear fuel tank depending on the position of the FUEL TANK FRONT/REAR selector switch. The turbochar-
ger dust detector indicator lights when either of the dust detector pressure switch plungers extend to close the re-
spective switch. The plunger extends when the filter strips in the compressor housings become restricted from dust
ingestion.
All engine gauges and indicators operate from system power (+24 -- 28 V dc) supplied from the master relay
through the 15--amp circuit breaker in the switch panel. Both the oil temperature and oil pressure transmitters are
engine mounted and each monitors its respective engine operating parameter. The electrical signal output of each
transmitter is sent directly to the corresponding gauge which, in turn, produces the indicated value as a function of
the input provided. Similarly, the two liquid quantity transmitters, which are mounted in the front and rear fuel tanks,
monitor the level of fuel in their respective fuel tank The FUEL TANK FRONT/REAR selector switch selects the
desired transmitter electrical signal output where it is routed to the FUEL TANK LEVEL gauge which produces the
indicated fuel level as a function of the input signal. When either of the turbocharger dust detector switches are
closed, a ground is applied to the TURBO DUST DET indicator to complete the electrical circuit and light the indica-
tor.
The transmission gauges and indicators electrical circuits include the TRANSMISSION TEMP gauge (transmission
temperature), TRANSMISSION PRESS gauge (transmission oil pressure), TRANSMISSION FILTER CLOGGED
indicator, transmission oil temperature transmitter, transmission oil pressure transmitter, transmission filter switch,
15 amp circuit breaker, 20--amp circuit breaker, and related electrical wiring, The TRANSMISSION TEMP and
TRANSMISSION PRESS gauges display the current transmission oil temperature and transmission oil pressure,
respectively. The TRANSMISSION FILTER CLOGGED indicator, when lit, signifies that the transmission filter is
clogged and needs to be serviced. The transmission gauges and indicator operate whenever the MASTER switch
is turned ON; however, if the engine is not running, the gauges normally will not show any readings. An exception
would be the oil temperature gauge if the engine was just turned off. In this case, a reading will be shown on the oil
temperature gauge while the transmission oil is still hot.