Tweco 181i Thermal Arc Fabricator - Manual (Page 38)

Fabricator 181i
INSTALLATION, OPERATION AND SETUP 3-8 Manual 0-5191
2. Digital Wirespeed/Amperage Meter (Left Digital Display)
This digital meter displays preview Wirespeed in MIG mode only then actual amperage (weld current) once
an arc has been established. It also displays preview amperage in both the STICK and LIFT TIG modes only
then actual amperage (weld current) once an arc has been established.
At times of non-welding, the amperage meter will display a preview value in both STICK and LIFT TIG modes.
This value can be adjusted by varying the amperage potentiometer (Control No. 3). At times of non-welding,
the amperage meter will preview a wirefeed speed value (Inches Per Minute) in MIG mode only. This can be
identified as preview wirefeed speed by a decimal point at the lower right hand side of the display.
When welding, the amperage meter will display actual amperage (weld current) in all modes.
At the completion of welding, the amperage meter will hold the last recorded amperage value for a period of
approximately 10 seconds in all modes. The amperage 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.
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.
3. Wirespeed/Amperage Control
In MIG mode, the Wirespeed/Amperage control knob adjusts the speed of the wire feed motor (which in turn
adjusts the output current by varying the amount of MIG wire delivered to the welding arc). The optimum wire
speed depends upon the material type and the welding application. The setup chart on the inside of the wire
feed compartment door provides a brief summary of the required settings for a basic range of MIG (GMAW/
FCAW) welding applications.
In STICK and LIFT TIG modes, the Wirespeed/Amperage control knob adjusts the amount of amperage (weld
current) delivered to the welding arc by the Power Source. It directly adjusts the Power Source to deliver the
desired level of weld current.
4. MIG Gun Adaptor (Tweco Style)
The MIG Gun adaptor is the connection point for the Tweco Fusion MIG Gun. Connect the MIG Gun by pushing
the MIG Gun connector into the brass MIG Gun Adaptor firmly and screw the locking screw in the MIG Gun
Adapter within the Wire Feed Compartment to secure the Tweco Fusion MIG Gun in position. Failure to properly
lock the MIG Gun into the MIG Gun Adapter will result in the MIG Gun being pushed out of the MIG Gun Adapter
by the MIG welding wire or lack of shielding gas (porosity in the weld) at the weld zone.
5. Positive Welding Output Terminal
The positive welding terminal is used to connect the welding output of the Power Source to the appropriate
welding accessory such as the MIG Gun (via the MIG Gun polarity lead), electrode holder lead or work lead.
Positive welding current flows from the Power Source via this heavy duty bayonet type terminal. It is essential,
however, that the male plug is inserted and turned securely to achieve a sound electrical connection.
CAUTION
Loose welding terminal connections can cause overheating and result in the male plug being fused in
the bayonet terminal.