Lincoln Electric BIG RED 500 Service Manual page 71

E-3
ENGINE ALTERNATOR, AND ENGINE SHUTDOWN CIRCUITS
FUEL
SOLENOID
OIL
TEMP.
ENGINE ENGINE
SWITCH
+ +
SHUTDOWN
PROTECTION
LIGHT RELAY
OIL
TIME
PRESSURE
DELAY
SWITCH
RELAY
RUN / STOP
SWITCH
BATTERY, RUN/STOP SWITCH,
STARTER, ENGINE ALTERNATOR,
AND ENGINE SHUTDOWN
CIRCUITS
The 12VDC battery supplies power to the engineʼs
Starter/Solenoid, the engineʼs Alternator and, through
the Run/Stop switch, to the engineʼs shutdown circuit-
ry.
When the Run/Stop switch is closed (run position)
12VDC is applied to the Timer Delay Relay, the Engine
Shutdown Relay, and via the Engine Shutdown Relay
to the Fuel Shutdown Solenoid. 12VDC is also applied
to the various engine sensors and gauges.
When the Run/Stop switch is closed and the Start
Button is pushed the Starter/Solenoid and the Fuel
Solenoid will be energized. When the Run/Stop switch
is closed, the Timer Delay Relay allows 60 seconds for
the engine to be started and oil pressure to "open" the
normally "closed" oil pressure switch. In the event of a
low oil pressure or high oil temperature condition the
Engine Protection Relay will activate and de-energize
the Fuel Shutdown Solenoid and the engine will stop
running. The Engine Protection Light will also come
on.
THEORY OF OPERATION
FIGURE E.2 - BATTERY, RUN/STOP SWITCH, STARTER,
TO
HOT START
RELAY
OIL
OIL
FUEL
TEMP.
PRESSURE
SENSOR
SENSOR
SENSOR AND
AND
AND
GAUGE
GAUGE
GAUGE
MECHANICAL
COUPLING
DIESEL
ENGINE
STARTER
ENGINE
SOLENOID
ALTERNATOR
START
BUTTON
12 VDC
BATTERY
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion
BIG RED
THREE PHASE
RECTIFIER
+
TAPPED
REACTOR
SELECTOR
STICK/TIG
SWITCH
AUXILIARY
STATOR
65 VAC
ROTOR
SHAFT
AUXILIARY
WELD
ROTOR
ROTOR
WELD
STATOR
FIELD
RECTIFIER
FINE
CURRENT
CONTROL
PART OF
STICK/TIG
115/230 VAC
SWITCH
RECEPTACLES
TO
HOT
TAPPED
START
REACTOR
RELAY
12 VDC
When the Run/Stop switch is opened (stop position)
the 12VDC is removed from the Fuel Shutdown
Solenoid and the engine stops running.
® 500/600
HOT
START
CIRCUIT
PART OF
SWITCH
65 VAC
150 VAC
FIELD
FEEDBACK
AUXILIARY
ROTOR
FLASHING
CIRCUIT
E-3
+