The circuit-breakers with non compensated thermal tripping elements have a tripping current level that depends on the surrounding temperature. When the temperature in which the CB is located exceeds its reference temperature, it will therefore be “derated”.

While,for compensated thermal-magnetic tripping units,they include a bi-metal compensating strip which allows the overload trip-current setting (Ir or Irth) to be adjusted, within a specified range, irrespective of the ambient temperature.

Released for:Schneider Electric Nigeria