ARMY TM 9-6115-672-14
AIR FORCE TO 35C2-3-444-32
MARINE CORPS TM 09244A/09245A-14
Output Supply System.
The Output Supply System (Figure 1-27) consists of the AC generator, ground fault circuit interrupter,
CONVENIENCE RECEPTACLE, current transformer, voltage reconnection terminal board, AC circuit
interrupter, load output terminals, AC CIRCUIT INTERRUPT switch, load sharing synchronizer, automatic
voltage regulator, CIM display screen FREQ gage, VOLTAGE gage, and POWER gage.
Power created by the generator is supplied through the current transformer, voltage reconnection terminal
board, and AC circuit interrupter to the load output terminals. The voltage reconnection terminal board allows
configuration of the generator set for 120/208 volt connections or 240/416 volt connections. The AC
CIRCUIT INTERRUPT switch closes and opens the AC circuit interrupter. This enables or interrupts power
flow between the voltage reconnection terminal board and load output terminals. The voltage regulation
system (paragraph 1.14.4) senses generator output voltage and provides a control signal to the generator
exciter to maintain the desired generator output voltage. Generator output frequency is controlled by the
governor control system (paragraph 1.14.3) and is read on the CIM display screen FREQ gage (Hz). The
current transformer provides a reduced current signal to the DCS and CIM display screen GEN CURRENT
indicators (amps AC). The CIM display POWER gage (kW) provides an indication of the power being used
by the load. The GEN CURRENT indicators indicate percent of rated current being supplied to the load. The
AC circuit interrupter will open and disconnect the load whenever any of the following faults occur: reverse
power, undervoltage, overload, overspeed, low oil pressure, high water temperature, or short circuit.
The AC generator also provides 120 VAC power to the CONVENIENCE RECEPTACLE through the
GROUND FAULT CIRCUIT INTERRUPTER.
General. Revolving field type generators have a DC field revolving within a stationary AC winding called the
stator. See generator schematic, Figure 1-28. AC power is distributed from the generator through leads
connected to the stator windings. There are no sliding contacts between the AC winding and the load,
therefore, great amounts of power may be drawn from this generator.
To energize the field, DC excitation must be applied to the generator field coils. The excitation current is
supplied from a brushless exciter mounted on the generator shaft.
The brushless exciter is actually an AC generator with its output rectified through a full wave bridge circuit.
This type of brushless exciter will provide the necessary excitation current. The generator set field flash
circuit, activated during each engine start, applies voltage to the exciter stator to begin the voltage build-up
process to energize the generator field.
The generator output voltage is controlled by controlling the alternating field current. This is accomplished by
regulating the exciter field coil voltage. The exciter field coil voltage is regulated with a solid state type
automatic voltage regulator.
Damper Bars. Damper bars are inserted through the field laminations and welded at the end to a solid copper
plate. The damper windings provide stable parallel operation, reduce damping current losses, and limit the
increase of third harmonic voltage with increase in load.
Brushless Exciter. The brushless exciter consists of an armature with a three-phase AC winding and rotating
rectifier assembly within a stationary field.