Hobart 9OC24S Operation Manual page 53

GENERATOR DIVISION
HOBI\RT BROTHERS COMPANY
OPERATION, MAINTENANCE, AND OVERHA.UL MANUAL, TM-240A
SELF-PROPELLED GENERATOR SET, SPEC. NO. 5381A
(5) Lights
and
light controls
Three, shielded instrument pane I I ights (3) are mounted along the top of the
instrument pane I. They are controlled by a toggle switch (23) and protected
by 20-A fuse (21). Headlights are controlled by a toggle switch (26) and pro-
tected by a 20-A fuse (22).
(6) Generator control tray (See Figure 6)
The generator control tray contains instruments and controls for monitoring
and controlling the generator output.
(a) Resistors
Two, 25-ohm, loo-watt, ballast resistors (1) are connected in series
in the generator DC field circuit.
A variable resistor (12) is connected in series between the manual control
rectifier (15) and rheostat (14). Its purpose is to adjust the DC voltage
to the rheostat.
(b) Generator output monitors (meters)
The generator output is monitored by three instruments; a frequency meter
(8), a voltmeter (7), and an ammeter (6). The frequency meter is a
resonant-reed type, and indicates the frequency of the generator output
alternating current in the range of 380 to 420 Hz (cycles per second).
The voltmeter indicates the generator output voltage in each phase-to-
neutral (A-N, B-N and C-N) or phase-to-phase (A-B, B-C and C-A)
as selected by the meter selector switch (5) and the line selector switch
(4). (These switches will be described below.) The voltmeter has a
3-l/2-inch face and the scale is graduated 0 to 300 V. The ammeter
is also 3-l/2-inch size and is graduated 0 to 500 A. The amperage
value in each of the three phases may be read on the ammeter by select-
ing the desired phase with switch (5). Three ammeter current trans-
formers (Ref. Fig. 10, item 3) lower the output load current to a lesser
value, of definite ratio, which will operate the ammeter movement with-
out damage. The ammeter dial scale is graduated and numbered so that
the pointer will indicate the true load current value rather than the
meter movement current.
(c) Meter and line switches
Ott 30/73
These switches provide a means of selecting and determining which phase
of voltage and current is indicated on the voltmeter ,and ammeter and
whether the voltage is I ine-to-neutral or I ine-to-l ine .
The meter switch
l-l
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