TM 5-3805-255-14
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ELECTRICAL SYSTEM
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The electrical circuit employed in the H100C Loader is a 24VDC, negative ground system. Electrical energy stored
in the batteries is available upon demand to the system components. These components, which include the
instruments, are:
1. Headlights, Backup Lights, Stop and Taillights and Cranking Motor. Dependent upon battery energy until
the engine drives the generator at a speed sufficient to carry the electrical load. Above this predetermined
speed, electrical energy produced by the alternator supplies the normal demands of the system. A portion of
this energy is sent to the batteries to keep them in a state of full charge.
2. Regulator. Installed in the system to control the output of the alternator. By using a regulated control, electrical
energy produced by the alternator is supplied to the system components on demand.
3. Batteries. Either two 12VDC batteries or four heavy duty 6VDC batteries, wired in series, produce a 24VDC
system. The batteries are housed in each of the battery boxes located on the left- and right-hand sides of the
rear main frame. Hinged tops on the battery boxes provide easy access for servicing.
The system may be divided into two circuits; the cranking circuit, in use during engine starting, and the charging
circuit, supplying current to the remainder of the system which the engine is operating. In addition, the charging
circuit replaces electrical energy drained from the batteries.
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The alternator is an electrical energy producing unit designed to meet the increased demand for electrical energy
during low speed operation or at engine idle operation
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1. The battery and other electrical accessories in the electrical system operate on direct current which flows in
one direction only. For this reason it is necessary to change the AC current to DC current. This function is
performed by rectifying diodes.
2. A diode is an electrical device which changes or rectifies alternating current (AC) to direct current (DC) by
allowing current to pass through it freely in one direction but not in the other. It thus acts much like an electrical
check valve or the commutator on a DC generator.
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