SIRIUS 3RT1023-1BB40-ZW95 — 24 VDC Power Contactor, Size S0
The Siemens 3RT1023-1BB40-ZW95 is a SIRIUS power contactor in size S0, designed for switching motor loads in industrial control panels. Its 24 VDC coil draws 5.4 W holding power, and the contactor is rated for AC-3 duty at 4.5 kW at 500 V and 5.5 kW at 690 V — covering common 400 V and 690 V three-phase motor circuits across Europe and export markets. The coil's pick-up and hold power are identical at 5.4 W DC, which simplifies the DC supply sizing — no inrush surge beyond the steady-state draw. The contactor mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 50022, fitting standard enclosure backplates. Rated operational current at AC-12 (resistive load) is 10 A maximum, while the AC-4 (plugging/reversing) rating is 8.5 A at 400 V — useful for high-duty-cycle applications like hoists or reversing conveyors where the contactor makes and breaks stalled-rotor current.
Coordination and Protection
Short-circuit protection coordination is specified for both Type 1 and Type 2. With Type 2 coordination (no damage to the contactor after a fault), the required upstream fuse is gL/gG 25 A. For Type 1 coordination (contactor may need replacement after a fault), the fuse can be gL/gG 63 A. This lets the panel builder choose between tighter protection and higher fault-clearing capacity based on the application's risk profile. The contactor carries a pollution degree 3 rating, meaning it's suitable for industrial environments with conductive pollution or dry non-conductive pollution that becomes conductive due to condensation — typical for unsealed enclosures in factory floors.
Termination and Wiring
Main current circuit terminals are screw-type, accepting solid conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and up to 2x (0.75 to 4 mm²). For stranded conductors, the range is 2x (1 to 2.5 mm²) and 2x (2.5 to 6 mm²), with a maximum of 2x 10 mm². AWG equivalents for main contacts are 2x (16 to 12), 2x (14 to 10), and 1x 8. This covers most panel wiring from control circuits up to moderate motor power feeds. The contactor is 45 mm wide, 85 mm tall, and 101 mm deep — the depth dimension is the projection from the DIN rail, critical for enclosure depth planning. Side-by-side mounting is permitted with a 6 mm gap at the side for heat dissipation, allowing dense panel layouts without derating if the ambient stays within the -25 to +60 °C operating range.
Lifecycle and Sourcing
The reference code per DIN EN 81346-2 is Q, designating it as a switching device in the plant documentation system — useful for panel builders who tag components per IEC 81346 for maintenance and replacement traceability.