Siemens SIRIUS 3RT1024-1AK64 — Size S0 Power Contactor, 24 VDC Coil
The Siemens SIRIUS 3RT1024-1AK64 is an Size S0 power contactor from the SIRIUS brand series, designed for switching motor loads in control panels. It carries a 24 VDC coil rated at 10 A and is rated for AC-3 duty, with motor power output of 7.5 kW at both 500 V and 690 V. The coil operates on 50/60 Hz with a control voltage range of 0.8 to 1.1 times rated value.
Ratings and Duty Class — What They Mean for Fit
The AC-3 rating defines the contactor's capability for starting and disconnecting squirrel-cage motors under load. At 400 V, the AC-3 motor power is not explicitly listed but the AC-2 rating at 400 V is 5.5 kW, and the AC-4 rating at 400 V is 12.5 A. AC-4 covers inching and plugging duty where the contactor makes and breaks stalled-rotor current — the 12.5 A figure is the one to size against if your application includes frequent reversing or jogging. The coil holds at 24 VDC nominal; the listed 10 A at 24 V is the contact rating for the auxiliary contacts, not the coil draw. The coil draw itself is not listed here, but the auxiliary contact ratings at other voltages — 2 A at 60 VDC, 1 A at 110 VDC, 0.3 A at 220 VDC, and 6 A at 230 VAC — define what the built-in aux can switch for signaling or interlocking. The main circuit uses screw-type terminals rated for 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), max. 2x (0.75...4 mm²) solid. The auxiliary circuit also uses screw terminals. For AWG, main contacts accept 2x (16...12), 2x (14...10), 1x 8; aux contacts accept 2x (20...16), 2x (18...14), 1x 12.
Coordination and Protection
Type 1 coordination (no damage to the contactor under short circuit, but may require contact replacement) requires a gL/gG fuse rated at 63 A. Type 2 coordination (contactor remains operational after a short circuit) requires a 25 A gL/gG fuse. These values govern the upstream fuse selection for the main power circuit. Mechanical life rated at 10,000,000 operations. Ambient temperature range -25 to +60 °C. Pollution degree 3 tolerates conductive pollution typical for industrial control panels.