Siemens 3TB43 Three-Phase AC Contactor 115V Coil

Siemens 3TB43 is a three-pole AC contactor (motor starter) from Siemens' World Series, designed to switch three-phase loads in industrial control circuits. The unit uses a 115 V coil (nominal 115 VAC, compatible with 110–120 VAC control systems) to pull in its main contacts, enabling L1-L3 to connect to T1-T3, and it is rated to carry up to 22 A at up to 600 VAC. This makes it suitable for controlling standard industrial motors, pumps, fans, and conveyors in 50/60 Hz environments. The 3TB43 family can be ordered with various auxiliary contact configurations; for example, the 3TB43-17-0A-J2 variant includes two normally open and two normally closed auxiliary contacts, which supports interlocking, signaling, and control logic in more complex circuits. The compact 3-pole design helps reduce panel space, and the contactor is compatible with common motor protection schemes, typically used alongside overload relays and appropriate fusing in motor control centers.