Siemens SIRIUS 3RT1023-1AG24 — Power Contactor, Size S0, 24 VDC Coil
The Siemens SIRIUS 3RT1023-1AG24 is a size S0 power contactor rated for switching motor loads up to 5.5 kW at 690 V (AC-3 duty), with a 24 VDC coil.
The AC-3 motor-switching rating at 400 V is 4 kW, and at 690 V it reaches 5.5 kW — that is the load the contactor can make and break under full motor inrush. The AC-4 rating (plugging / inching duty) at 400 V is 8.5 A, which is lower than the AC-3 current because the contactor must interrupt stalled-rotor current on every cycle. For resistive loads (AC-1), the maximum continuous current is 10 A at 24 V, tapering to 0.3 A at 220 V and 3 A at 400 V — the voltage derating curve matters if you are switching heaters or lighting banks at higher line voltages. The coil pulls 0.8 to 1.1 A at 50 Hz and 0.85 to 1.1 A at 60 Hz at rated voltage — a 24 VDC coil draws that same holding current continuously, so factor it into the control transformer sizing.
Screw-type terminals on the main circuit accept 2x (1 to 2.5 mm²) solid or stranded, up to 2x 10 mm² maximum. The control circuit terminals take 2x (0.5 to 1.5 mm²) solid, 2x (0.75 to 2.5 mm²) stranded, or max 2x (0.75 to 4 mm²). AWG equivalents for the main contacts are 2x (16 to 12) solid, 2x (14 to 10) stranded, or 1x 8. The contactor carries two instantaneous auxiliary contacts (1 NO + 1 NC) for feedback or interlocking.