Siemens 3RT2028-1BB40 Three-Phase AC Contactor

Siemens 3RT2028-1BB40 is a 3-pole power contactor designed for AC-3e/AC-3 duty, making it suitable for reliably switching three-phase motors in industrial control panels and automation systems. It is rated for up to 38 A at 400 V AC and capable of handling about 18.5 kW at 400 V, driven by a 24 V DC coil, and it includes one normally open and one normally closed auxiliary contact. The unit uses screw terminals and is sized for the S0 footprint with upright mounting, pairing a compact 3-pole package with DC coil operation for straightforward control wiring. This configuration supports motor-start and stop tasks in automation systems and pairs with compatible protective relays and control circuitry for integrated protection and sequencing.