Round terminal blocks. These terminal blocks are intended to be placed in tubes, or to go into round
holes during their installation. Care must be taken to ensure that the terminal screw heads remain permanently at a sufficient distance from the tube if it is metallic. If a minimum clearance of 4mm in air is not achievable, we recommend the installation of an insulating sheath around the terminal block, for example high temperature heat-shrinkable sleeve, or Kapton tape, whose temperature resistance is compatible with the conditions of the installation. This insulation must provide an electric strength of 2500V minimum (More details on EN60698-1§13).