Contactor selection brief
The Siemens SIRIUS 3RT1023-1AP00-ZW98 is a size S0 power contactor with three normally-open main contacts and a 230 V 50 Hz coil. It mounts on a 35 mm DIN rail per EN 50022, using either the integrated snap-on feature or screws. The 45 mm width and 85 mm height fit standard panel layouts, and side-by-side mounting is permitted with no additional clearance between units. For motor duty, the AC-2 rating at 400 V is 4 kW, covering slip-ring motor starting and reversing. The AC-4 rating at 400 V is 8.5 A, which governs plugging and inching cycles where the contactor makes and breaks stalled-rotor current. The AC-12 resistive load maximum is 10 A, suitable for heater or lighting banks. Short-circuit coordination is specified for both Type 1 and Type 2. With Type 2 assignment (no welding after fault clearance), the required upstream fuse is gL/gG 25 A. With Type 1 (welding permitted but no fire risk), the fuse can be gL/gG 63 A. This lets the panel designer choose between tighter protection and higher fault tolerance.
Terminal and wiring data
Main circuit terminals are screw-type, accepting 2x (1 to 2.5 mm²), 2x (2.5 to 6 mm²), or a single conductor up to 10 mm². The AWG equivalents are 2x (16 to 12), 2x (14 to 10), or 1x 8 AWG. Auxiliary contact terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or a maximum of 2x (0.75 to 4 mm²). Strip lengths and torque values follow the standard Siemens SIRIUS terminal schedule. The contactor is rated for pollution degree 3, meaning it tolerates conductive pollution or dry non-conductive pollution that becomes conductive due to condensation. This is typical for industrial control panels not in sealed or climate-controlled environments. The front face carries IP20 finger protection; the terminals themselves are IP00, so they must be guarded within the enclosure.
Coil and auxiliary contact ratings
The coil operates at 230 V 50 Hz with a voltage tolerance of 0.8 to 1.1 times the rated value, so the pickup range is 184 V to 253 V. Dropout typically occurs below about 0.6 times rated, per the SIRIUS family characteristic. The coil draws a holding current consistent with the S0 frame size; inrush is higher during pickup but the control transformer should be sized for the sealed VA. Auxiliary contacts (integrated or add-on block) are rated for switching at various voltages: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC. These ratings follow the IEC 60947-5-1 utilization categories. For DC switching at higher voltages, the current must be derated significantly due to arc extinction limits.
Environmental limits and endurance
Operating temperature range is -25 °C to +60 °C, covering most indoor industrial environments. Maximum installation altitude is 2 000 m without derating. The mechanical endurance is rated at 10 million operating cycles, which is typical for the SIRIUS S0 frame and reflects the contactor's design for high-duty applications.