WFU12-4C
15
1. Burn back adjustment
This determines how much of the wire is left sticking out of the contact tip when welding is stopped.
Too much wire and there is a chance of it ‘freezing’ in the weld pool as it cools, too little and there is a
chance that the wire will burn back into the contact tip, necessitating changing of the tip. Adjusting the
control anti-clockwise increases the amount of wire sticking out of the tip and adjusting it clockwise
reduces it.
2. Wire speed control
Adjusts the speed of the wire feed system up to a maximum of 23m/min.
3. Voltage control
Controls the welding voltage when used in conjunction with a Newarc R4/5000 multi-process or
constant voltage power source.
4. Latch
Changes the mode of operation of the MIG torch switch between 2T and 4T. In 2T, the MIG torch switch
is pressed to start welding and released to stop. In 4T, the torch switch is pressed and released to start
welding and pressed and released again to stop welding.
MIG Welding
• It is assumed that the wire and welding torch have been fitted as per the installation part of this
manual.
• Set the Voltage control and wire speed controls proportional to the thickness of metal to be
welded.
• Select the welding torch mode required.
• Ensure the gas cylinder is turned on and the flow-meter or regulator is set to give approximately 15
to 20 Litres per minute. (30 to 40 cubic feet per hour).
• Until you are familiar with the machine it is preferable to start welding on a piece of waste material
the same type and thickness as the work-piece, adjust the voltage control (if fitted), wire feed and
gas flow until the required welding condition is achieved.
When used with the Newarc power sources all the controls can be adjusted whilst welding without
damaging the machine.
