Hobart 120CU20, Operation And Maintenance Manual With Illustrated Parts List

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OM-2228 / Operation and Maintenance Manual
120CU20 / Series 500120 / 400 Hz. Generator Set
October 15, 2013 Chapter 1-1
Page 14
(8) “ENGINE STOP” push-button switch (S76).
When the “ENGINE STOP” push-button switch is pressed, the red indicator will glow. Then a 3 -
5 minute delay will occur to permit the turbo and other engine components to cool evenly. After
the delay, power is disconnected from the engine ECM causing the engine to shut down.
(9) Engine voltmeter (M5).
The voltmeter indicates the voltage across the 12 VDC batteries. It is graduated 10 V to 16 V.
(10) Engine fuel gauge (M13).
An electric fuel gauge receives its controlling signal from a sending unit in the fuel tank. 12 VDC
operating power is supplied to the fuel gauge when the “
ENGINE START” push-button switch is
pressed. The fuel level can also be checked when the unit is not running by pressing the panel
light
“LAMPS” push-button switch.
(11) Fault Code meter and “ TEST/RESET” push-button switch (M6, S77)
The function of the fault code meter is to indicate to the operator, that an abnormal condition of
over voltage, under frequency, etc. occurred, which caused the protective monitoring system to
function. When one of the circuits are activated, it shows the code on the fault code meter. The
fault will remain on for a short period or until the “
TEST/RESET” push-button switch is pressed.
Pressing the “TEST/RESET” push-button switch can also test the fault code meter operation. A
meter test should be performed only when disconnected from a load, as the contactor(s) will open
during the test cycle.
(12) Engine systems fault codes.
Fault codes will be shown to warn the operator of abnormal engine operations that must be
corrected. These indicators are over temperature, air cleaner restriction, low oil pressure, and
low fuel indication.
(13) AC Generator output monitors (meters).
Three instruments, a frequency meter, a voltmeter, and an ammeter monitor the generator output.
The frequency meter is an analog type and indicates the frequency of the generator output
alternating current in the range of 360 to 440 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 SELECT” switch. The voltmeter has a scale of 0 to 300
V. The ammeter has a scale of 0 to 500 A. The amperage value in each of the three phases
may be read on the ammeter by selecting the desired phase with “
METER SELECT” switch. The
ammeter current transformers, located in the output power module circuit, lower the output load
current to a lesser value, of definite ratio, which is sent to the Voltage Regulator PC Board (REG).
The ammeter dial scale is numbered so that the pointer will indicate the true load current value.
(14) Load contactor indicating lights [Yellow # 1 and Orange # 2] (S75, S275)
Indicating lights within the respective contactor control push-button switches ( “OUTPUT NO. 1”
and or “OUTPUT NO. 2” ) glow when the circuit is energized, indicating that power is available at
the plug. When the load contactor opens for any reason, the light is turned OFF.