This part of IEC 60974 is applicable to power sources for arc welding and allied processes designed for industrial and professional use@ and supplied by a voltage not exceeding 1 000 V@ or driven by mechanical means. This part of IEC 60974 specifies safety and performance requirements of welding power sources and plasma cutting systems. This part of IEC 60974 is not applicable to welding power sources for manual metal arc welding with limited duty operation which are designed mainly for use by laymen and designed in accordance with IEC 60974-6. This part of IEC 60974 is not applicable to testing of power sources during periodic maintenance or after repair. NOTE 1 Typical allied processes are electric arc cutting and arc spraying. NOTE 2 AC systems having a nominal voltage between 100 V and 1 000 V are given in Table 1 of IEC 60038:2009. NOTE 3 This part of IEC 60974 does not include electromagnetic compatibility (EMC) requirements.