Series are fully Thyristorised TIG / MMA DC power source with built-in HF for excellent professional TIG / MMA welding applications. SSR 400-T can meet the stringent demands of radiographic quality welding needs of nuclear power plants, process industries, offshore, defense, steel plants, thermal power plants, mining, structural fabrications, etc. True vertical characteristics and excellent dynamic response ensure arc stability Irrespective of input voltage fluctuation ± 10% or operator's hand movement to achieve spatter-free welding.