ESAB LHF 630 is a thyristor-controlled welding rectifier designed for hand welding, TIG welding, and arc-air gouging. Its mains voltage compensation ensures constant welding current and arc voltage regardless of mains voltage variations. The LHF 630 features a voltmeter and ammeter for precise monitoring of welding parameters. It also has an "anti-stick" function to prevent the electrode from sticking to the workpiece and a start surge to facilitate striking and restriking of the electrode.