Tweco Hefty II CC CV Voltage Sensing Wire feeder - Manual (Page 18)

Internal Controls And
Connections (Component Side):
See Figure 3-3 for details.
7. CC/CV MODE SWITCH - The CC position pro-
vides a voltage sensing wire feed speed mode of
operation for use with constant current (CC) power
sources. The CV position provides a constant wire
feed speed mode of operation for use with constant
voltage (CV) power sources.
NOTE: This switch does not select a CC or
CV mode of operation. The mode of opera-
tion is set by the type of power source being
used.
8. INPUT CIRCUIT BREAKER - This circuit
breaker provides complete system protection for the
wire feeder in the case of a fault or overload condi-
tion.
9. 12 VDC DRIVER PCB - The 12 VDC driver
printed circuit board (PCB) is primarily responsible
for controlling the contactor and gas valve.
10. MOTOR CONTROL PCB - The motor control
printed circuit board (PCB) is primarily responsible
for controlling the output speed of the motor.
11. CONTACTOR - The contactor controls the
“on/off” flow of weld current from the power source.
When the contactor is open, the welding wire is
electrically “cold.” When the contactor is closed, the
welding wire is electrically “hot.”
CAUTION: The contactor is rated for
330 amps of weld current at a 60% duty
cycle. Exceeding the current or duty cy-
cle ratings will damage or shorten the
life of the contactor.
12. GAS VALVE - The gas valve controls the
“on/off” flow of shielding gas through the welding
gun.
Figure 3-3 Internal Controls And Connections
(Component Side)
430429-456
DESCRIPTION OF EQUIPMENT
June 5, 2000 Revised 3-5