Hobart 9OC24S Operation Manual page 49

GENERATOR DIVISION
HOBART BROTHERS COMPANY
OPERATION, MAINTENANCE, AND OVERHAUL MANUAL, TM-240A
SELF-PROPELLED GENERATGR SET, SPEC. NO. 5381A
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 beyond
the bearing and is attached to the engine flywheel by a hub and flexible disc
coupling assembly. The rear end of the rotor shaft extends rearward beyond the
rear bearing and into the exciter stator housing. The exciter rotor is mounted on
this shaft extension with a Woodruff key.
A disc or "flywheel" at the rear of the exciter rotor provides a facility for mount-
ing a clutch pressure plate and disc, when the generator is used in a self-propelled
unit. A rectifier with six diodes is mounted on the exciter rotor and converts exciter
ACoutput to DC for excitation of the generator revolving fields. The exciter DC
output to the generator fields, and consequently the generator output, is controlled
by the amount of DC voltage supplied to exciter fields by the static voltage regula-
tor . A centrifugal, radial-blade type fan, mounted on the hub and coupling
assembly, draws cooling 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 (See Fig. 5)
The control box is a sheet metal enclosure which houses and provides mounting
facilities for generator and engine controls and monitoring equipment. In addition
to instruments and controls which are surface mounted on the left side of the front
panel, the box is equipped with three, drawer type trays which contain generator
output control devices and monitoring instruments. Trays slide in and out on nylon
rollers for easy access to internally mounted components. Each tray is easily re-
movable by disconnecting an "Amphenol" connector, unlocking safety latches,
and sliding the complete tray assembly out of the control box.
' (1) Engine instruments
Engine operation is monitored by an ammeter (4), a coolant temperature
gage (ll), and an oil pressure gage (8). An hour-meter (6) records engine
operating time.
(a) Ammeter
The ammeter (4) indicates the direction and value of current flow in
the 12-V DC electrical system. Its graduated range is from -60 A
through 0 A, to -1-60 A.
(b) Temperature gage
Ott 30/73
The temperature gage (11) is a mechanical type of unit construction.
It consists of a panel mounted indicating mechanism which is connected
by a capillary tube to a bulb mounted in the engine cooling system. The
-gage indicates engine coolant temperature in the range of lOOoF to 2200F.
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