It is the core switching element in a starter or feeder circuit, energizing the coil to close the main poles and connect the load.
Rated for a permissible ambient air temperature of -40 to 60 °C, with derating allowed up to 70 °C. That means it can live in unheated enclosures or near ovens, as long as the thermal curve is respected above 60 °C — a common reality in panel builds where heat rise from multiple devices stacks. Operating altitude covers 0 to 3000 m, which covers most industrial sites except high-mountain installations. Above 3000 m, air density drops and dielectric withstand and cooling degrade, so this part is not rated for those conditions. Control circuit voltage limits are specified for DC operation: drop-out occurs at 0.1 to 0.3 Uc across -40 to 70 °C; operational range is 0.75 to 1.2 Uc from -40 to 55 °C, narrowing to 1.0 to 1.2 Uc from 55 to 70 °C. This means the coil hold-in is tight at high temperature — verify your control supply stays above 1.0 Uc when the panel is hot.