IEC 60974-13:2021 pdf download – Arc welding equipment – Part 13: Welding current return clamp.
1 Scope This part of IEC 60974 is applicable to WELDING CURRENT RETURN CLAMPS for arc welding processes, designed to make an electrical connection to the workpiece without using tools. This document is not applicable to WELDING CURRENT RETURN CLAMPS for underwater welding and plasma cutting. This document specifies safety and performance requirements of WELDING CURRENT RETURN CLAMPS . This document does not specify requirements for welding cables. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-1 51 :2001 , International Electrotechnical Vocabulary (IEV) – Part 151: Electrical and magnetic devices IEC 60050-1 51 :2001 /AMD1 :201 3 IEC 60050-1 51 :2001 /AMD2:201 4 IEC 60050-1 51 :2001 /AMD3:201 9 IEC 60050-1 51 :2001 /AMD4:2020 IEC 60974-1 :201 7, Arc welding equipment – Part 1: Welding power sources IEC 60974-1 :201 7/AMD1 :201 9 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-1 51 , IEC 60974-1 , as well as the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 WELDING CURRENT RETURN CLAMP WORK CLAMP , US RETURN CURRENT CLAMP , UK clamp that is attached to, or in contact with, the workpiece, to connect the welding return cable to the workpiece [SOURCE: IEC 60050-851 :2008, 851 -1 4-36]
9 Mechanical requirements 9.1 R ETAINING MEANS A WELDING CURRENT RETURN CLAMP shall be designed to maintain sufficient electrical contact in normal service and to prevent the unintentional separation of the WELDING CURRENT RETURN CLAMP as a result of a longitudinal pull. Where springs are incorporated in the WELDING CURRENT RETURN CLAMP , they shall not constitute part of the current path unless they are permanently by-passed by a fixed conductor capable of carrying the test current given in Table 1 . Conformity shall be checked by visual inspection and the following test: A WELDING CURRENT RETURN CLAMP is fitted in accordance with the manufacturer’s instructions, with a welding cable of maximum cross-sectional area 5 m length and its coupling device. The welding cable is folded to form a bundle not exceeding 0,4 m in length. The clamp is attached to a clean mild steel plate 3 mm thick. The steel plate is positioned such that the cable bundle applies a vertical longitudinal force on the clamp for 1 min. Test is passed if the WELDING CURRENT RETURN CLAMP remains attached to the steel plate. 9.2 Welding cable entry The cable entries of the WELDING CURRENT RETURN CLAMP shall be designed so as to prevent damage to the cable due to flexing. Conformity shall be checked by visual inspection.
9.3 Welding cable connection The design of the WELDING CURRENT RETURN CLAMP shall be such that welding cables with a cross-sectional area within the range as specified by the manufacturer can be replaced. The connection shall withstand the mechanical stress of the following tensile test without separation. A clamp may be provided with adaptor to enlarge the fitting range. Conformity shall be checked by visual inspection and by the following test: A WELDING CURRENT RETURN CLAMP is fitted in accordance with the manufacturer’s instructions, with a welding cable of maximum cross-sectional area. The connection is subjected to 1 0 pulls with a force of 40 N per mm 2 of the cross-sectional area with a maximum of 2 000 N applied to the welding cable. The force of each pull is gradually increased from zero to the specified value in 1 s and maintained for 1 s. After the test, the conductor shall not have been displaced by more than 2 mm.