標準號：IS 7931 Pt.2-1975
發布日期：1976/4/1 12:00:00
實施日期：1999/12/31 12:00:00
適用范圍：1.1 This standard ( Part II) covers transformer-rectifier power source of the substantially flat load characteristics type incorporating monocrystalline and polycrystalline rectifiers for semiautomatic and automatic arc welding with self-adjusting arc ( MIG/MAG processes). Equipment covered by this standard will normally be of the air cooled or forced air cooled type.1.1.1 This standard does not cover oil cooled transformer rectifier power source.1.2 The windings of transformer-rectifiers covered by this standard are of insulation classes A, E, B, F and H.1.3 Welding transformer-rectifier covered by this standard are assigned ratings on the basis of duty cycle.