Tweco 181i Thermal Arc Fabricator - Manual (Page 40)

Fabricator 181i
INSTALLATION, OPERATION AND SETUP 3-10 Manual 0-5191
Note that the Local/ Remote Switch (Control No. 18) located in the wirefeed compartment should be set to
Remote for remote amperage/voltage controls to operate.
9. Multifunction Control - Voltage, Down Slope & Arc Force
The multifunction control knob is used to adjust Voltage (MIG Mode), Down slope (LIFT TIG Mode) and Arc
Force (STICK Mode) depending on the welding mode selected.
NOTE
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.
When MIG Mode is Selected
In this mode the control knob is used to adjust the MIG welding voltage of the Power Source. The welding
voltage is increased by turning the knob clockwise or decreased by turning the knob counterclockwise. The
optimum voltage level required will depend on the type of welding application. The setup chart on the inside
of the wire feed compartment door provides a brief summary of the required output settings for a basic range
of MIG welding applications.
When STICK Mode is Selected
In this mode the multifunction control knob is used to adjust arc force. Arc force control provides an adjustable
amount of welding force (or “dig”) control. This feature can be particularly beneficial in providing the operator
the ability to compensate for variability in joint fit-up in certain situations with particular electrodes. In general
increasing the arc force control toward ‘10’ (maximum arc force) allows greater penetration control to be
achieved. Arc force is increased by turning the control knob clockwise or decreased by turning the knob
counterclockwise.
When LIFT TIG Mode is Selected
In this mode the multifunction control knob is used to adjust down slope. Down slope allows the user to
select the ramp down time of the amperage at the completion of the weld. The main function of down slope
is to allow the welding current to be gradually reduced over a pre-set time frame such that the welding pool
is given time to cool sufficiently.
Note that when in 2T normal mode (Control No. 11), the Power Source will enter down slope mode as soon
as the trigger switch is released (ie if the multifunction control knob is set to 5, the Power Source will ramp
down from the present welding current to zero over 5 seconds). If no down slope time is set then the welding
output will cease immediately. If the Power Source is set to 4T latch mode, to enter down slope mode the
trigger must be held in for the selected time period (ie press and release trigger to commence welding, then
press and hold trigger again to enter down slope mode). Should the trigger be released during the down slope
phase (4T only), the output will cease immediately.
10. Arc Control (Inductance)
The arc control operates in MIG mode only and is used to adjust the intensity of the welding arc. Lower arc
control settings make the arc softer with less weld spatter. Higher arc control settings give a stronger driving arc
which can increase weld penetration. Soft means maximum inductance while Hard means minimum inductance.
11. Trigger Mode Control (MIG and LIFT TIG Mode only)
The trigger mode control is used to switch the functionality of the of the MIG or TIG Trigger Switch between
2T (normal) and 4T (latch mode)