Hobart 9OC24S Operation Manual page 50

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HOBART BROTHERS COMPANY
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OPERATION, MAINTENANCE, AND OVERHAUL MANUAL, TM-240A
SELF-PROPELLED GENERATOR SET, SPEC. NO. 5381A
(c) Oil pressure gage
The oil pressure gage (8) is a bourdon type and indicates engine lubricating
oil pressure. It is graduated from 0 PSI to 75 PSI.
(d) Hourmeter
The hourmeter (6) is electrically driven from the 12-V DC battery system.
The hourmeter measures and records engine running time when the ignition
switch is ON, and will record up to 9999.9 hours on five revolving drums.
(e) Fuel gage _
An electric fuel gage (1) indicates the quantity of fuel in the 70-gallon
fuel tank. It is graduated in fractions from E (empty) through l/4, l/2,
3/4 to F (full).
(2) Engine controls
A lo-ampere fuse (10) protects the hourmeter (6), back-up light circuit, and
engine safety device circuit. Twelve-volt DC power to the 400-Hz generator
protective devices must also pass through this fuse.
The engine control switch (2), sometimes referred to as the "permissive-start"
switch, is a three-position, toggle type. The three positions are identified
as START, RUN, and STOP. The switch is spring-loaded in START position
and must be manually held in this position. When released from START it
automatically returns to RUN position. When held in START position, 12-V
DC power is supplied directly to the fuel shut-off valve solenoid and engine
'shutdown safety switches are by-passed. This direct current is necessary for
engine starting because the low oil pressure switch is OPEN until the engine
is running normally. When released, the switch will automatically reposition
to RUN and supply power to the fuel shut-off valve through the engine shut-
down safety switch circuit. A green light (9) gl ows to indicate that the engine
control switch is in RUN (or START) position. In STOP position the switch
contacts are open and holding power is disconnected from the fuel valve, allow-
ing the valve to close and shut-off fuel to the engine.. A pushbutton start switch
(5) closes the starter solenoid circuit to crank the engine. A starting aid con-
trol (7) actuates the ether injection mechanism for cold weather starting.
(3) Operating mode control switch
This is a two-position switch (20), sometimes identified as the GEN DRIVE
(generate-drive) switch, and is used to select the mode of operation desired --
either GENERATE for supplying power to an aircraft, or DRIVE for mobile
operation of the vehicle. In GEN position, the switch performs a triple
l-l
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Oct. 30/73