IEC 60947-7-1:2009 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 1 000 V a.c. up to 1 000 Hz or 1 500 V d.c. This 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. The main technical modifications of this standard since this previous publication are listed below: - added in the scope that this standard may be used as a guide for special types of terminal blocks, for example with diodes or varistors or similar component holders; - the conventional free air thermal current added in 5.2 in the list of information to be stated by the manufacturer; - update of 7.1.4 that the colour combination green-yellow is not allowed for terminal blocks; - the consequences in case of failed single tests and failed tests within test sequences specified in 8.2; - requirements regarding clearances and creepage distances replaced by reference to Annex H of IEC 60947-1, Annex A dele...