Firepower MST 180i Operating Manual page 39

Note that when operating in LIFT TIG mode, the Power Source will remain activated until the selected Downslope time
has elapsed (refer Control No. 9).
12. Process Selection Control
The process selection control is used to select the desired welding mode. Three modes are available, MIG, LIFT TIG and
STICK modes. Refer to section 3.15 or 3.16 for MIG (GMAW/FCAW) set up details, section 3.17 for LIFT TIG (GTAW)
set-up details or section 3.18 for STICK (SMAW) set-up details.
Note that when the Power Source is powered OFF the mode selection control will automatically default to MIG mode.
This is necessary so as to prevent inadvertent arcing should an electrode holder be connected to the Power Source and
mistakenly be in contact with the work piece during power up.
13. Digital Voltage Meter (Right Digital Display)
The digital voltage meter is used to display the both the preview voltage (MIG mode only) and actual output voltage (all
modes) of the Power Source.
At times of non-welding, the voltage meter will display a preview value in MIG mode. This value can be adjusted by varying
the multifunction control knob (Control No. 9). Note that in STICK and LIFT TIG modes, the voltage meter will not preview
welding voltage but will display Open Circuit Voltage in STICK mode and 0V in LIFT TIG mode.
When welding, the voltage meter will display actual welding voltage in all modes.
At the completion of welding, the digital voltage meter will hold the last recorded voltage value for a period of approximately
10 seconds in all modes. The voltage meter will hold the value until; (1) any of the front panel controls are adjusted in
which case the Power Source will revert to preview mode, (2) welding is recommenced, in which case actual welding
amperage will be displayed, or (3) a period of 10 seconds elapses following the completion of welding in which case the
Power Source will return to preview mode.
The preview functionality provided on this power source is intended to act as a guide only. Some differences may
be observed between preview values and actual welding values due to factors including the mode of welding,
differences in consumables/gas mixtures, individual welding techniques and the transfer mode of the welding arc
(ie dip versus spray transfer). Where exact settings are required (in the case of procedural work), it is recommended
that alternate measurement methods be utilized to ensure output values are accurate.
14. Thermal Overload Indicator
This welding Power Source is protected by a self resetting thermostat. The indicator will illuminate if the duty cycle of the
Power Source has been exceeded. Should the thermal overload indicator illuminate the output of the Power Source will be
disabled. Once the Power Source cools down this light will go OFF and the over temperature condition will automatically
reset. Note that the power switch should remain in the on position such that the fan continues to operate thus allowing the
Power Source to cool sufficiently. Do not switch the Power Source OFF should a thermal overload condition be present.
15. Gas Inlet (MIG mode only for MIG Gun or Spool Gun operation)
The Gas Inlet connection is used to supply the appropriate MIG welding gas to the Power Source. Refer to section 3.15
or 3.16 for MIG (FCAW/GMAW) set up details.
Only Welding Shielding Gases specifically designed for arc welding applications should be used.
16. ON / OFF Switch
This switch is used to turn the Power Source ON/OFF.
When the front digital displays are lit, the machine is connected to the Mains supply voltage and the internal
electrical components are at Mains voltage potential.
Manual 0-5339
NOTE
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WARNING
WARNING
3-11
Firepower MST 180i
INSTALLATION, OPERATION AND SETUP