Siemens 3RT1526-1BB40 Contactor

Siemens 3RT1526-1BB40 is a four-pole AC-3 power contactor designed for motor control up to 11 kW at 400 V with a 24 V DC coil. The device uses a size S0 enclosure with screw-terminals for the main circuit and includes two normally open plus two normally closed auxiliary contacts, providing flexibility for start/stop sequencing and interlock functions in 3‑phase drives. The main circuit is rated for 25 A and the insulation voltage is listed up to 690 V, making it suitable for standard industrial three‑phase distribution and motor applications. The coil operates at DC 24 V, enabling easy control from common PLC outputs, and the unit is specified with front IP20 protection. Mechanical life is listed in the tens of millions of cycles for the base unit, with the auxiliary contact block affecting overall lifecycle figures (typical values shown as 10,000,000 cycles for the base and non-electronic blocks, and around 5,000,000 cycles for electronics‑compatible auxiliary configurations). This Siemens contactor is commonly employed in automation panels to switch 3‑phase motors, fans, pumps, or conveyors at 400 V AC, delivering reliable on/off control with a compact S0 form factor.