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TM 10-3930-671-24
II.
Battery
Battery condition is very important for proper
starting.
The lead-acid storage battery, used on automotive and
industrial applications, is an electrochemical device for
converting chemical energy into electrical energy. It has
two major functions:
1.
It provides a source of current for starting the
engine.
2.
It can, for a limited time, furnish current when the
electrical demands of the unit exceed the output
of the alternator.
WARNING
Stop engine before checking battery
terminals or electrical connections.
Sparks or flames near a battery could
cause an explosion or fire. Battery
acid
can
cause
corrosive
bums.
Always wear eye protection. Use of
jumper cables or battery charging
should be done only as directed by
manufacturers’ safety instructions.
Refer
to
equipment
manufacturer
for
battery
recommendations.
III.
Alternator
The alternator differs from the conventional D.C. shunt
generator in that the armature is the stationary member
and is called the stator: while the field is the rotating
member and is called the rotor. Alternating current is
rectified (changed to direct current) by means of diode
rectifiers rather than mechanically with brushes coming
into contact with the various segments of the rotating
armature on the generator. With this construction, the
higher current values involved in the armature or stator
may be conducted to the external circuit through fixed
leads and connections rather than through the rotating
commutator and brushes as in D.C. generator. The
comparatively small values of current supplied to the
field may be conducted without difficulty through small
brushes and rotating slip rings. The alternator is
somewhat lighter and more compact in design than the
conventional D.C. generator of comparable electrical
size and is equally as simple to service and test. Each
bearing is prelubricated which eliminates the need for
periodic lubrication.
Precautions
to
be
observed
when
testing
or
servicing the alternator system:
1.
Disconnect the battery before connecting or
disconnecting
test
instruments
(except
voltmeter) or before removing or replacing any
unit or wiring. Accidental grounding or shorting at
the
regulator,
alternator,
ammeter,
or
accessories will cause severe damage to the
units and/or wiring.
2.
To avoid damage to the regulator, do not, at
anytime, connect battery to the regulator
field terminal.
3.
The field circuit must never be grounded, on
this system, between the alternator and the
regulator. Grounding of the field terminal either
at the alternator or regulator will damage the
regulator.
4.
If it is necessary to solder any lead to a
rectifier lead, use a pair of pliers as a heat dam
between the solder joint and the rectifier.
5.
The alternator must not be operated on open
circuit with the rotor winding energized.
6.
Do not attempt to polarize the alternator. No
polarization is required. Any attempt to do so
may result in damage to the alternator, regulator,
or circuits.
7.
Grounding of the alternator output terminal
may damage the alternator and/or circuit and
components.
8.
Reversed battery connections may damage
the rectifiers, wiring, or other components of
the charging system. Battery polarity should
be checked with a voltmeter before connecting
the battery.
9.
If a booster battery or fast charger is used,
Its polarity must be connected correctly to
prevent damage to the electrical system
components (positive to positive, negative to
negative.)
IV.
Regulator
Most regulators are fully transistorized and completely
sealed. These cannot be adjusted or repaired, and it can
be assumed that this type regulator will outlive the other
components in the charging system.
Other
regulators
are
adjusted
and
repaired
in
accordance with the manufacturer’s instructions.
F-160
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