Engine Control Panel (See Fig. 9); Engine Instruments; Engine And Generator Controls - Hobart 140GT17P Operation And Maintenance Manual With Illustrated Parts List

OM-2029
F. Engine Control Panel (See Fig. 9)
The engine control panel is mounted directly below the control box. In addition to engine controls
and instruments, generator output controls are mounted here. A plexiglass window in the canopy
rear door, slants outward at the bottom to form an opening for access to controls when the door is
closed.

(1) Engine instruments

Engine operation is monitored by an ammeter (3) , a coolant temperature gage (5) , and an oil
pressure gage (4) . An hourmeter (6) records engine operating time.
(a) Ammeter
• The ammeter (3) 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 +60 A.
(b) Temperature gage
• The temperature gage (5) indicates the engine coolant temperature and is actuated by a
temperature sender (19, Fig. 3) mounted on the engine's water jacket. The gage indicates
engine coolant temperature in the range of 100F to 220F.
(c) Oil pressure gage and oil pressure switch
• The oil pressure gage (4) displays the pressure in the engine's lubrication system. It is op-
erated by an oil pressure sender (17, Fig. 3) mounted on the engine block.
• The switch connects 12-V DC power to the engine control system and to the generator 12-
V DC control system when the engine is running.
(d) Hourmeter
• The hourmeter (6) is electrically driven from the 12-V DC battery system. The hourmeter
measures and records engine running time and will record up to 9999.9 hours on five re-
volving drums. The hourmeter operates only when the engine is running and the oil pres-
sure switch is closed.

(2) Engine and generator controls

(a) Engine-generator control switch
• The engine-generator control switch (15) (also identified as the "build-up-voltage, generate,
idle" switch) is a three-position toggle type. It is spring-loaded in one position, BUILD-UP-
VOLTAGE, and will automatically reposition to GENERATE position when released. In
BUILD-UP-VOLTS position it performs a dual function. First, it supplies power to the gover-
nor control box, which allows the engine to operate at normal governed speed; second, it
momentarily supplies current for closing the excitation-deenergization relay contacts, to
make three-phase, 115-V AC power available to the voltage regulator, or to the manual
voltage control circuit for excitation of the generator exciter. In GENERATE position, power
is maintained to the governor control box and to the excitation relay. When the switch is
placed in IDLE position, power is disconnected so that the engine returns to idle speed and
the exciter field is deenergized.
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September 30/89 Revised