Adopts IEC60947-7-1, Ed. 3.0 (2009) which specifies requirements for terminal blocks with screw-type or screwless-type clamping units primarily intended for industrial or similar use and to be fixed to a support to provide electrical and mechanical connection between copper conductors. It applies to terminal blocks intended to connect round copper conductors, with or without special preparation, having a cross-section between 0.2mm2 and 300mm2 (AWG 24/600kcmil), intended to be used in circuits of a rated voltage not exceeding 1,000V a.c. up to 1,000Hz or 1,500V d.c.