Siemens 3TH4271-0BB4 Electromechanical Contactor

Siemens 3TH4271-0BB4 is an 8-pole electromechanical contactor relay (71E) from the 3TH4 family, built for DIN EN 50011 mounting with a 24 V DC control coil. It provides 7 normally open and 1 normally closed auxiliary contacts via screw terminals, and it mounts on a 35 mm DIN rail with compact dimensions of 78 mm high, 45 mm wide, and 135 mm deep. The device is rated for 10 A at 230 V AC (AC-15) and 6 A at 400 V AC, making it suitable for motor control and other inductive loads in automation panels. It features IP00 protection (IP20 if screws are tightened for the installed contacts) and is designed for long life, with a B10 life up to 1,000,000 cycles under high-demand conditions. Standards conformance includes DIN EN 50011 (71E), and its 7 NO + 1 NC configuration supports reliable status signaling and interlocking in control circuits and machine automation applications.