Motor switching and panel fit
The 3RT2037-3AB00-Z X95 is a size S2 power contactor from the Siemens SIRUS 3RT2 series, rated for AC-3e/AC-3 duty at 65 A — that's 30 kW on a 400 V three-phase motor. AC-3e is the enhanced version of AC-3, covering standard squirrel-cage motors with occasional inrush; the 65 A figure governs the continuous motor current the contactor can switch without derating. The 24 V AC 50 Hz coil keeps control transformer sizing straightforward in panels where AC control voltage is already present. Termination is mixed: screw terminals on the main circuit for high-current power wiring, spring-loaded terminals on the control and auxiliary circuit for faster wiring of the coil and aux contacts. The built-in 1 NO + 1 NC auxiliary contact block covers basic feedback and interlocking without an add-on module. Size S2 means it occupies a standard DIN-rail footprint and aligns with Siemens S2 busbar and accessory system for panel integration.