TM-9-2350-256-10

AUXILIARY POWER UNIT (APU)

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Voltage Regulator (Figure 15, Item 1)

— voltage regulator receives 28 Vdc from the starter/generator

(Figure 15, Item 3) and provides 28 ±0.7 Vdc to charge the vehicle batteries. Voltage regulator is

equipped with a resettable circuit breaker. If the circuit breaker opens due to an over-voltage condition, a

reset button can be pushed to reset the circuit breaker.

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Engine (Figure 15, Items 2 and 5)

— is an overhead-valve, two-cylinder, four-cycle, air-cooled, diesel

engine. Both the ONAN (Figure 15, Item 5) and the HATZ (Figure 15, Item 2) engines burn fuel drawn

from the right rear fuel tank. Engine drives starter/generator (Figure 15, Item 3) and auxiliary hydraulic

pump (Figure 15, Item 4).

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Starter/Generator (Figure 15, Item 3)

— connected to the APU engine by a chain. Chain driven by the

APU engine, the 300-A 28-volt generator functions as the starter motor. Power from the batteries is used

to power the starter/generator when starting the APU. Once the APU is started, the starter/generator

generates 28 Vdc and delivers it to the voltage regulator to charge vehicle batteries and supply electrical

power to the vehicle.

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Auxiliary Hydraulic Pump (Figure 15, Item 4)

— supplies hydraulic pressure to run the impact wrench

and refuel/defuel pump under normal operations, or raise/lower the spade or boom, and retrieve cables

under no-load conditions under emergency operations.

Figure 15.

Auxiliary Power Unit (APU).

TM 9-2350-256-10

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TM-9-2350-256-10 - Page 59 of 796