Generator; Control Box Assembly - Hobart 140GT17P Operation And Maintenance Manual With Illustrated Parts List

D. Generator
The 400-Hz generator is a brushless, revolving field, three-phase, alternating current type. The rotor
assembly is mounted by two, permanently lubricated, sealed, ball bearings. The front bearing is sup-
ported by the fan housing; the rear bearing is mounted in the exciter housing. Both of these housings
are attached to the main generator stator housing. The front end of the rotor shaft extends forward be-
yond the rear bearing and into the exciter stator housing. The exciter rotor is mounted on this shaft ex-
tension with a Woodruff key and is secured by a washer and 1/2"-13 thd, cap screw. A rectifier with
six diodes is mounted on the exciter rotor and converts exciter AC output to DC for excitation of the
generator revolving fields. The exciter DC output to the generator fields, and consequently the gener-
ator output, is controlled by the amount of DC voltage supplied to exciter fields by the static voltage
regulator. A centrifugal, radial-blade fan which is part of the hub and coupling assembly, draws cool-
ing air over all internal windings. Air enters at the exciter end and is discharged at the drive end. The
complete generator is bolted to the engine flywheel housing.
E. Control Box Assembly
The control box (Fig. 6) is a sheet metal enclosure which houses and provides mounting facilities for
generator controls and monitoring equipment. Switches, meters, indicator lights, and circuit breakers
which control and help to monitor the generator are all mounted on the front panel of the control box.
This panel is hinged on the right side, and can swing open for access to the interior panel where the
generator PC board assemblies and relays are mounted. A shielded, instrument panel light is
mounted near the top of the control box front panel, to illuminate controls and instruments on the
panel.
September 30/89 Revised
OM-2029
Control Box
Figure 6
1-1
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