TM 9-8000
field. The strength of the field is thereby increased,
generator. Where two generators are working in a
giving a higher generator output to take care of the
Single set of batteries and a single electrical System, the
lighting load.
problem of paralleling exists. That is, the two generators
must be connected in parallel. Unless special provision
d. If the lights are turned on before the generator
is made, trouble may result if two generators are parallel.
The reason for this is that one generator may attempt to
circuit breaker closes, the entire lighting current is
carry most or all of the load while the other generator
supplied by the battery. This current then flows through
might use current or act like a motor. The problem is
all of the series field, instead of through section 1 only, in
further complicated if one of the generators varies in
the same direction as the shunt field, making the total
speed (as the unit on the power plant might).
field strength still greater. This will build up the generator
b. System Description. To provide effective paralleling,
voltage to close the circuit breaker. The entire current
each of the voltage regulators contains an additional
output of the generator that passes through the circuit
paralleling winding. These windings become connected
breaker flows to the center tap of the series field, where
to each other through two paralleling relays when both
it divides. Part of the current then flows in one direction
generators are operating.
With this condition, the
through to the battery and the remainder flows to the
paralleling windings can increase the voltage and thus
lights.
the output) of the generator that is producing more than
its share. Therefore, the two generators can be kept in
e. As soon as the circuit breaker closes, the generator
step.
begins to pick up the lighting load. This lessens the
drain on the battery and thereby reduces the current
flowing through section 2 of the series field. When the
13-19. Generator System - Main and Auxiliary
generator output just equals the lighting current, the
Generators.
current in section 2 is zero and, as the generator output
increases further, current begins to flow in the reverse
a. General. A wiring circuit of a combat vehicle using a
direction through section 2 to the battery. This tends to
main and auxiliary generator is shown in figure 13-18 in
weaken the field built up by the shunt winding and
schematic form. This system uses two generators, two
section 1 of the series winding. By obtaining the proper
carbon-pile regulators, plus various relays and switches.
relationship between the shunt winding and the two
The following chart identifies the circuits in figure 13-18.
sections of the series winding, results quite similar to
those obtained from voltage regulation are secured, and
CIRCUIT
CIRCUIT NAME
the battery is kept in a charged condition.
1
Main Generator Feed
f. The charging rate of the split-series field generator
2
Main Gen Positive Line
may be adjusted by shifting the third brush as in the
7
Battery Ground
regular third-brush generator. In some generators of this
10
Instrument Panel Feed
type, separate coils are used for the two sections of the
61
Auxiliary Generator Field
series field. In others, the two sections are combined
62
Aux Gen Positive Line
into one coil. Generators of this type do not have
65
Auxiliary Engine Starter
standard connections and must not be confused with the
81
Battery - Positive Line
ordinary third-brush generator. Neither terminal should
421
Aux Eng Fuel Cutoff Valve
be grounded under any circumstances.
422
Aux Eng Magneto Ground
459
Master Relay Control
13-18. Paralleling Generators.
459B
Master Relay Feed
478A
Aux Gen Equalizing
a. General. Some military vehicles have two separate
478M
Main Gen Equalizing
506
Main Gen Warning Light
working into a common set of batteries. Certain combat
508
Aux Gen Warning Light
vehicles have a single power plant, but they also carry an
auxiliary
13-18
Previous Page
