Lincoln Electric COMMANDER SVM153-A Service Manual page 48

E-2
FIGURE E.2 - BATTERY, ENGINE, ROTOR, STATOR, PULL COIL BOARD
COMMANDER 500
ENGINE
STARTER
ALTERNATOR
RUN/STOP
SWITCH
SENSORS
S
BATTERY
H
BOARD
U
I
T
D
D
L
O
120 10 E
W
VDC VDC
N R
BATTERY
SOL
PULL
COIL TO WELD
BOARD CONTROL
SOL
BOARD
10
VDC
PERIPHERAL
BOARD
GENERAL DESCRIPTION
The Commander 500 is a diesel engine-driven welding
power source capable of producing 500 amps at
40VDC at a 100% duty cycle. The engine is coupled to
a brush-type alternating current generator. This AC
output is rectified and controlled by Chopper
Technology to produce DC current for multi-purpose
welding applications. The Commander 500 is also
capable of producing 12,000 watts of AC auxiliary
power at 100% duty cycle.
BATTERY, ENGINE, ROTOR,
STATOR, PULL COIL BOARD AND
PERIPHERAL BOARD – ENGINE
PROTECTION
The 12VDC battery powers the engine starter motor
and also supplies power to the Battery PC board, Pull
Coil PC board, Peripheral PC board and associated
circuitry. When the engine, which is mechanically cou-
pled to the rotor, is started and running, the 12 VDC
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
THEORY OF OPERATION
AND PERIPHERAL BOARD – ENGINE PROTECTION
E
W
MECHANICAL
ROTATION
SLIP
RINGS
STATOR
ENGINE
AUXILIARY
1/2
BATTERY
BD
1
2
0
V
A
C
COMMANDER 500
THREE-PHASE
RECTIFIER
(2)
+
80 VDC
W
I
D
N
L
D
I ANALOG
N
POWER SUPPLY
G
BOARD
TO
ROTOR
IDLE
HOLD
COIL
THERMAL
LIGHT
42 VAC TO 14 PIN AMPHENOL
FOR WIRE FEEDER
WINDINGS
240VAC
RECEPTACLE
120VAC
RECEPTACLES (2)
battery voltage is fed through the Battery PC board to
the rotor field coil via a brush and slip ring configura-
tion. This excitation or "flashing" voltage magnetizes
the rotor lamination. This rotating magnet induces a
voltage in the stationary windings of the main alterna-
tor stator. The stator houses a three-phase weld wind-
ing, a 120/240VAC single-phase auxiliary winding, and
a 42VAC wire feeder power winding.
The engine alternator supplies charging current for the
battery circuit. The Peripheral board monitors the
engine sensors and will shut the engine off in the event
of low oil pressure, engine over temperature, malfunc-
tion of the engine's alternator system or a low fuel con-
dition. The idler solenoid is mechanically connected to
the engine's throttle linkage. If no welding or auxiliary
current is being drawn from the Commander 500, the
Pull Coil board activates the idler solenoid, which then
brings the engine to a low idle state. When output cur-
rent is sensed, either weld or auxiliary, the Weld
Control PC board deactivates the idler solenoid, and
the engine returns to high RPM.
WORK
TERMINAL
TO WELD
CONTROL
BOARD
POWER MODULES
(2)
(2)
ELECTRODE
TERMINAL
IGBT
CHOKE
SHUNT
F
E
E
D
(2)
PWM
B
20 VDC
SIGNALS (2)
A
C
K
WELD
CONTROL
BOARD
VOLTMETER
AMMETER
ARC OUTPUT PROCESS/RANGE
CONTROL CONTROL SELECTOR
E-2
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