Thermal derating and conductor range
The 5SM1742-0: The 25 A rating holds at 40 °C and 45 °C ambient. Above that, derate linearly: 24 A at 50 °C, 23 A at 55 °C, 22 A at 60 °C, 21 A at 65 °C, and 20 A at 70 °C. If the panel ambient runs above 45 °C, size the upstream protective device for the derated value, not the nameplate 25 A. The terminal accepts solid or stranded copper from 1.5 mm² up to 25 mm², covering most distribution and subfeed circuits. Tightening torque is 2.5 to 3 N·m.
Installation and environment
Mounts on DIN rail in any position — no orientation restriction. Supply can enter from top or bottom, which simplifies busbar routing in a crowded enclosure. IP20 rating applies when installed in a distribution board with connected conductors; the device itself is finger and back-of-hand safe per the shock protection class. Ambient temperature range is -40 to +60 °C for storage/transport, with operating range -5 to +45 °C. Overvoltage category III, so it is rated for fixed installation downstream of the main distribution board. Silicon-free construction (no silicone outgassing) matters if the panel also contains sensitive contacts or optics.