Tweco 500P PowerMaster - Manual (Page 34)

POWERMASTER 500, 500P, 350
OPERATION 4-2 Manual No. 0-4749
4.02 Power-Master 500 and 350 Controls
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Art # A-06857
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WARNING
POWER
10A
REMOTE
LOCAL
CONTACTOR
Figure 4-1: Power-Master 500 and 350 Front Panel
1. Control Power ON/OFF Switch: This circuit breaker/
switch activates the controls on the power source.
When this switch is in the OFF position, the power
source is in standby mode. There is still line voltage
present internal to the machine, but the controls are
not energized. In the ON position the control power is
applied and the controls are energized. In the ON
position the digital display should be on. This circuit
breaker/switch also protects the auxiliary 24 VAC and
120 VAC power in the case of an overload.
2. Mode Select Switch: The mode select switch is a four-
position switch used to select the weld process. The
four modes are as follows:
GTAW mode: In this mode the power source
operates in constant current mode with a lift arc
starting circuit activated and arc force/inductance
disabled. The lift arc circuit allows the arc to be
initiated by momentarily touching the tungsten to
the work and then lifting. The lift arc circuit limits
the “touch” current to a low value and then switches
to preset current after lifting. The lift arc feature
can be disabled if desired to allow “scratch” starting
by moving two jumpers internal to the machine on
the main control board. (See configuration settings
under Installation instructions Section 3.07 of this
manual for an explanation of how to disable the lift
arc feature)
SMAW mode: In this mode the power source
operates in constant current mode with the arc
force control enabled.
CAG mode: In this mode the power source operates
in constant current mode with arc force/inductance
control disabled.
GMAW mode: In this mode the power source
operates in constant voltage mode with the
inductance control enabled. A Wire-Sharpening
circuit is also active to help condition the end of
the wire when the weld is complete to improve the
arc start on the next weld. The Wire-Sharpening
feature can be disabled if desired. (See
configuration settings under Installation
instructions Section 3.07 of this manual for an
explanation of how to disable the Wire-Sharpening
feature).
3. Output Contactor Indicator: This green light will be
ON whenever the output of the welding machine is
energized.
4. Output Contactor Switch: This switch is used to
energize the output of the machine.
5. Overtemp Indicator: This amber light will be ON
whenever an overtemperature condition has been
detected internal to the machine. This light will remain
on with the fans running until the unit cools down. If
this light is on, the output of the machine will be
disabled. Once the machine cools down this light will
go off and the overtemperature condition will
automatically reset.