ARMY TM 9-6115-672-14
AIR FORCE TO 35C2-3-444-32
MARINE CORPS TM 09244A/09245A-14
1-32
The stationary exciter field assembly is mounted in the main generator frame. The exciter armature is press fit
and keyed onto the shaft assembly. The rotating rectifier assembly slides over the bearing end of the generator
rotor shaft and is secured with bolts and washers to an adapter hub which is shrunk on the generator shaft.
1.16.12.4
Rotating Rectifier Bridge. The rotating rectifier bridge consists of rectifying diodes mounted on a brass heat
sink which is in turn mounted on an insulating ring. The entire assembly bolts to the adapter on the generator
shaft. Therefore, the rotating rectifier assembly will rotate with the exciter armature eliminating the need for
any sliding contacts between the exciter output and the alternator field.
1.16.12.5
Exciter Field. The exciter field on the high frequency exciter consists of laminated segments of high carbon
steel which are fitted together to make up the field poles. The field coils are placed into the slots of the field
poles.
1.16.12.6
Exciter Field Coil Voltage Source. Field coil DC voltage is obtained by rectifying the voltage from a phase to
neutral line of the generator output, or other appropriate terminal, to provide the needed voltage reference.
The rectifier bridge is an integral part of the static regulator. The static regulator senses a change in the
generator output and automatically regulates current flow in the exciter field coil circuit to increase or decrease
the exciter field strength. An external adjust rheostat sized to be compatible with the regulator is used to
provide adjustment to the regulator sensing circuit.
1.16.12.7
Balance. The rotor assembly is precision balanced to a high degree of static and dynamic balance. Balance is
achieved with the balance lugs on the field pole tips. The balance will remain dynamically stable at speed in
excess of the design frequencies.
1.16.12.8
Bearing. The generator rotor assembly is suspended on shielded, factory lubricated ball bearings. They are
greased for life and do not require lubrication.
1.16.12.9
Stator Assembly. The stator assembly consists of laminations of steel mounted in a rolled steel frame.
Random wound stator coils are fitted into the insulated slots.
1.16.13
Generator Set Controls.
1.16.13.1
Engine Starting System.
1.16.13.1.1 Engine starting is accomplished primarily with two 12 volt batteries, connected in series to provide 24 VDC
power, and a starter (Figure 1-29). The starter includes a cranking motor and a solenoid. To permit engine
starting, the DC CONTROL POWER circuit breaker must be pushed in, the DEAD CRANK switch must be in
the NORMAL position, and the BATTLE SHORT switch must be in the OFF position. In addition, any
ENGINE SHUTDOWN fault previously registered on the CIM display screen must have been corrected by
activating the FAULT RESET switch.
When the ENGINE CONTROL switch is then placed in the START position, the starting circuits supply 24
VDC power to the starter. As the engine accelerates to approximately 900 RPM, the DCS speed control unit
disconnects power from the starter.
