The Siemens 3RT2037-3AB00-Z W97 is a size S2 power contactor from the SIRIUS family, rated for AC-3e/AC-3 duty at 65 A and 30 kW at 400 V. That AC-3 rating means it's specced for switching squirrel-cage motors — starting, stopping, and inching under load — not just resistive heaters. The 24 V AC 50 Hz coil keeps control circuit wiring consistent with legacy panel transformers; verify your control transformer VA budget because the coil inrush at pickup can pull several times the sealed VA.
Terminal configuration and wiring
Main circuit uses screw terminals; control and auxiliary circuits use spring-loaded terminals. That split means the power wiring gets the torque-retention of a screw clamp for the 65 A path, while the control wiring benefits from faster spring-cage termination — no re-torquing on the aux side. The auxiliary contact block is built in: 1 NO + 1 NC, so you get a status feedback pair and a seal-in pair without adding a side-mount block. Size S2 footprint fits standard DIN rail; the packaging dimensions of 122.5 x 62.0 x 142.0 mm give you the envelope for panel layout.