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Note: When welding with remote foot pedal
Pre-set amperage in LED display will show what the maximum amperage foot pedal will go to
(what base amperage control knob is set to), upon welding it will show actual welding amperage.
Upon pressing of foot pedal welding arc will start, if you find it hard to start arc push pedal down a
bit further to aid starting.
The benefits of welding with remote foot pedal is greater control of amount of heat going into work
especially beneficial on alloys as these absorb the heat much quicker than steel. Press pedal fully
to start weld, upon weld pool formation you can slightly release the pedal to decrease amperage to
sustain perfect weld pool and increase again as required to sustain weld characteristics.
The foot pedal adjusts from Start (min) current to Max current set on base current knob on front of
machine as shown in LED before welding.
Tips for AC Welding
The TIG251 offers two significant advantages over conventional silicon rectifier SCR transformer
power sources.
1. The AC square wave balance (SP%) can be set to a higher percentage electrode negative
(decrease below 50%) which minimizes tungsten heating and erosion
2. The AC square wave frequency can be varied to focus the arc and achieve quicker travel
speed
Increasing the AC frequency above 60Hz will narrow the cone shape arc from the
tungsten’s tip.
Decreasing the AC frequency below 60Hz will broaden the cone shape arc from tungsten’s
tip.
120 Hz
60 Hz
The two above benefits above can be used to maintain a tight focus of arc for precise heat control &
tight joint access. Because of the TIG251 Inverter Technology the following recommendations are
made as a starting point.
The other benefits are quicker travel speed the higher the AC frequency, thus increasing output
A 2% Thoriated tungsten is recommended instead of pure tungsten normally used for AC welding.
Thoriated tungsten’s emit electrons easier and therefore will improve starting.
