The Siemens 3RF3090-1AA02 is a 1-pole solid-state relay from the SIRIUS 3RF30 family, in a 45 mm wide housing with screw terminals. For motor loads, derate per the AC-51 or AC-53a curves in the datasheet; the 90 A figure is the thermal current (Ithe), not the locked-rotor or inrush capability. Control is 24-230 V AC/DC, so it accepts a wide range of PLC or relay outputs without a separate interface module.
Integration notes — panel fit and wiring
The 1-pole configuration switches one phase; for three-phase loads, three units are needed. Control circuit is galvanically isolated from the load circuit, so a single 24 V DC PLC output can drive the relay without a separate power supply for the load side.
