Motor-load switching with a fixed auxiliary deck
The Siemens 3RT2027-1HA40 is a 3-pole power contactor rated AC-3e/AC-3 at 32 A, delivering 15 kW at 400 V for standard induction motor duty. The 12 V DC coil operates across a 0.7–1.25×Uc tolerance band, so it holds in at 8.4 V and pulls in reliably at 15 V — useful when the control supply sags under load. The built-in 1 NO + 1 NC auxiliary contact set is fixed; frame size S0 means no auxiliary switch block can be added later, so if your feedback circuit needs more than one mirror contact, spec the variant with the wider auxiliary deck from the start.
Panel fit and wiring constraints
Packaged dimensions are 92.0 × 54.0 × 115.5 mm — fits a standard DIN-rail footprint in the S0 frame envelope. Screw terminals accept the usual 0.75–2.5 mm² power wiring; the auxiliary terminals share the same pitch. No auxiliary switch can be stacked, so plan your NO/NC count at the order line. The 1-piece unit quantity matches line-item BOM quantities without fractional packaging.