This part of IEC 60947 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. lt applies to terminal blocks intended to connect round copper conductors, with or without special preparation, having a cross-section between 0,2 mm2 and 300 mm2 (AWG 24/600 kcmil), intended to be used in circuits of a rated voltage not exceeding 1000 V a.c. up to 1000 Hz or 1500 V d.c. NOTE AWG is the abbreviation of “American Wire Gage” (Gage (US) = Gauge (UK)) kcmil = 1000 cmil; 1 cmil = 1 circular mil = surface of a circle having a diameter of 1 mil 1 mil = 1/1 000 inchThis standard may be used as a guide for − terminal blocks requiring the fixing of special devices to the conductors, for example quick connect terminations or wrapped connections, etc.; − terminal blocks providing direct contact to the conductors by means of edges or points penetrating the insulation, for example insulation displacement connections, etc.; − special types of terminal blocks, for example with diodes or varistors or similar component holders, etc. Where applicable in this standard, the term “clamping unit” has been used instead of the term “terminal”. This is taken into account in case of reference to IEC 60947-1.