IEC 60352-7 pdf download.Solderless connections
1 Scope and object
This part of IEC 60352 is applicable to spring-clamp connections made with stripped wire without further preparation: – solid conductors of 0,32 mm to 3,7 mm nominal diameter (0,08 mm 2 to 10 mm 2 cross- section), or – stranded conductors of 0,08 mm 2 to 10 mm 2 cross-section, or – flexible conductors of 0,08 mm 2 to 10 mm 2 cross-section according to IEC 60228 or IEC 60189-3 for use in telecommunication equipment and in electronic devices employing similar techniques. Information on materials and data from industrial experience is included in addition to the test procedures to provide electrically stable connections under prescribed environmental conditions. The object of this part of IEC 60352 is to determine the suitability of spring-clamp connections under specified mechanical, electrical and atmospheric conditions. NOTE IEC Guide 109 advocates the need to minimize the impact of a product on the natural environment throughout the product life cycle. It is understood that some of the materials permitted in this standard may have a negative environmental impact. As technological advances lead to acceptable alternatives for these materials, they will be eliminated from this standard.
2 Normative references
The following referenced documents are indispensable for the application 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(581):1978, International Electrotechnical Vocabulary (IEV) – Chapter 581: Electro- mechanical components for electronic equipment Amendment 1 (1998) IEC 60068-1:1988, Environmental testing – Part 1: General and guidance Amendment 1 (1992) IEC 60189-3:1988, Low frequency cables and wires with PVC insulation and PVC sheath – Part 3: Equipment wires with solid or stranded conductor, PVC insulated, in singles, pairs and triples IEC 60228:1978, Conductors of insulated cables Amendment 1 (1993)
For the purpose of this part of IEC 60352, the terms and definitions of IEC 60050(581) and IEC 60512-1 and the following additional terms and definitions apply: 3.1 spring-clamp termination part of the contact or terminal to which one single conductor only is connected by means of a spring 3.1.1 universal spring-clamp termination spring-clamp termination intended to accept solid, stranded and flexible unprepared conductors 3.1.2 non-universal spring-clamp termination spring-clamp termination intended to accept conductors of one class only, for example solid conductors only, or conductors of two classes only, for example solid and stranded but not flexible 3.1.3 push-in spring-clamp termination non-universal spring-clamp termination in which the connection is made by pushing in a solid or stranded conductor 3.2 spring-clamp connection solderless connection achieved by clamping a conductor with a spring-clamp termination, see figure 1
4.1 Workmanship The connection shall be processed in a careful and workmanlike manner, in accordance with good current practice. 4.2 Tools Tools, if necessary, shall be used and inspected according to the instructions given by the manufacturer. 4.3 Spring-clamp terminations 4.3.1 Materials – Materials for the current-carrying parts: suitable grades of copper or copper alloy shall be used. – Materials for the spring-clamp parts: suitable grades of copper alloy or steel shall be used. 4.3.2 Surface finishes The contact area of the current-carrying parts shall be plated with tin or tin-alloy. The surface shall be free of detrimental contamination or corrosion. 4.4 Design features Spring-clamp terminations shall be designed so that the spring-clamp parts establish a sufficient force to produce a reliable connection. In a spring-clamp connecting device, each conductor shall be clamped individually. The openings for use of a tool intended to assist the insertion or withdrawal of the conductor shall be clearly distinguishable from the conductors entry hole. Dimensions The suitability of a spring clamp connection depends on the dimensions of the termination together with the characteristics of the materials used. The dimensions shall be chosen so as to be suitable for the wire or the range of wires for which the termination is designed. The suitability is verified by applying the test schedules given in clause 5. 4.5 Wires Wires with solid, stranded and flexible conductors according to IEC 60228 or IEC 60189-3 shall be used depending on the type of spring-clamp terminations. 4.5.1 Materials The conductor used shall be made of annealed copper.