TM 9-6115-669-13&P
Section III. PRINCIPLES OF OPERATION
1.13 GENERAL DESCRIPTION.
1.13.1 Technical Principles of Operation.
The operation of the Electric Power Plant III is essentially automatic and needs little attention from
the operator. Operator duties consist of positioning and setting up the unit, connecting electrical
cables, starting the Generator Sets 150 kW, putting the EPP III on-line, and monitoring operations.
When in operation, the generator regulator/monitor senses generator output voltage and maintains
it at a constant value. The generator electronic control senses generator output frequency and
controls engine speed to maintain a constant output frequency. In addition to the EPP III operator,
personnel in the Engagement Control Station (ECS) can also start and stop the Generator Sets 150
kW and monitor their functions.
The generator electronic control provides automatic control of the sequence of events during the
start cycle. The start cycle begins when the operator activates the glow plug and the engine begins
cranking. Fuel and ignition are turned on at a preset value; the ignition system is turned off
automatically. The engine continues to accelerate until it stabilizes at operating speed.
After the engine has been started and has stabilized at operating speed (normally within 15
seconds), the output voltage and frequency are manually adjusted to the appropriate levels. About
one minute after these values have been reached, the Generator Set 150 kW may be switched
on-line to supply power. When maintenance is to be performed on a Generator Set 150 kW that is
running, or when a problem occurs, the second generator is started and put on line before the first
is shut down.
Fuel for operation of the Generator Sets 150 kW is stored in one 100-gallon tank in each Generator
Set 150 kW. This provides 10 hours of continuous operation without refueling. The fuel system is
controlled and monitored automatically and status is indicated on a panel in the ECS.
Converting from road travel configuration into operational configuration:
For road travel configuration, all accessories are stowed in the requisite storage containers, and
cable drums are reeled in and locked in the stowed position. Side panels are raised so the truck is
ready to drive (figure 1-4a). For operational configuration, the EPP III provides power to the ECS
and RS on a stationary basis (figure 1-4b). This involves parking the truck in a suitable location,
folding down the side panels, unpacking accessories, and putting the EPP III into operational
condition.
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