Tweco 500P PowerMaster - Manual (Page 37)

POWERMASTER 500, 500P, 350
Manual No. 0-4749 4-5 OPERATION
circuit limits the “touch” current to a low value and
then switches to the preset current after the arc is
struck.
SMAW mode: In this mode the power sources
operates in constant current mode. The front panel
control can be used to preset the desired welding
amperage. The arc force control is activated for
SMAW mode allowing the amount of “dig” or arc
force to be set by the arc force control. Maximum
arc force is full clockwise, full counter clockwise is
zero arc force.
GMAW mode: In this mode the power source
operates in constant voltage mode. The front panel
control can be used to preset the desired welding
voltage. The inductance control is activated for
GMAW mode. The inductance control allows the
arc characteristics to be adjusted. Maximum
inductance is full clockwise. Higher inductance
settings make the arc “softer” with less spatter.
Lower inductance settings give a stronger “driving”
arc. Generally the inductance control can be set at
mid range as a good starting point.
The GMAW mode also has a built in wire-
sharpening circuit to help condition the end of the
wire at the end of the weld. This feature reduces
the size of the ball on the end of the wire to improve
the next arc start. The wire sharp settings can be
modified or disabled by using the programmer
interface.
PULSED GMAW mode: In this mode the power
source uses the built in pulse control for pulsed
GMAW welding. The pulse control is factory
programmed with 24 different pulse weld
schedules. The active pulse schedule is shown on
the pulse schedule display. The label on the inside
of the control door shows the pulse schedules as
shipped from the factory. Schedules 1 - 12 are
programmed as standard (non AVC) and schedules
13-24 are programmed as AVC schedules. The
AVC schedules provide for control of the arc length
as the torch to work distance is varied. In the
pulsed GMAW mode the front panel output control
is used to preset a pulse reference for the pulse
control circuit. The pulse schedules can be
modified by using the programmer interface.
7. Arc Force/Inductance Control: When the SMAW mode
is selected this control is activated and allows
adjustment of the amount of arc force or “dig”.
Maximum arc force is full clockwise, full counter
clockwise is zero arc force. For GMAW mode this
control can be used to adjust the amount of
“inductance” in the circuit. Higher inductance settings
make the arc “softer” with less spatter. Lower
inductance settings give a stronger “driving” arc.
Generally the inductance control can be set at mid
range as a good starting point. For GTAW and PULSED-
GMAW modes, this control is not active.
8. Contactor On Indicator: This indicator light is on
whenever the output of the power source is energized,
either by the contactor switch on the front panel or by
the remote gun switch signal.
9. Contactor Switch: This switch can be used to energize
the output of the power source, when a remote gun
switch is not being used. This switch would primarily
be used for SMAW welding or GTAW welding without
a remote pendant or foot pedal.
10.Pulse Schedule Display: This two digit display shows
the current selected pulse GMAW welding schedule.
The current schedule can be changed by using the
schedule up and down select buttons.
11.Pulse Schedule Select Buttons: These two buttons
can be used to select one of the built in pulse GMAW
welding schedules. These buttons can only be used
to change the pulse schedule when the output
contactor is off, see description 8 above.
12.Remote On Selector: This button allows the selection
of either remote control of the output or local (front
panel) control of the output. The indicator light next
to the switch will be on if remote control is selected,
and off if local control is selected. Remote control is
via either the 19 pin or 14 pin receptacle on the rear
panel of the power source.
13.Programmer Port: This port allows the connection of
the power source to a computer for accessing the
programmable features of the power source. This port
is configured for direct connection to a serial port on a
computer.
14.Output Negative Terminal: Connection point for
negative welding lead.
15.Output Positive Terminal: Connection point for
positive welding lead.