What this SIRIUS Size S6 contactor is and what it does
The Siemens 3RT1054-3AD36 is a SIRIUS-branded power contactor in the Size S6 frame, designed for switching motor loads and resistive loads in industrial control panels. It carries a 42-48 V rated coil voltage (AC or DC) and uses spring-type terminals for the magnet coil connection. The main circuit accepts stranded conductors from 16 to 70 mm², and the auxiliary circuit accepts solid or stranded 2x (0.25 to 2.5 mm²) wire. The contactor mounts via screw fixing, and the mounting position allows rotation up to +/-90° on a vertical surface, plus tilting +/-22.5° front-to-back. Operating temperature range is -25 to +60 °C, with storage from -55 to +80 °C. The contactor includes an auxiliary switch block as standard.
Key ratings and what they mean for fit
The headline rating to check first is the coil voltage: 42-48 V. This is not a 24 V or 110 V coil — if your control circuit runs at 48 V nominal, this is a direct fit; if it runs at 42 V, it still pulls in reliably. The coil operates on AC or DC, so no polarity worries on DC circuits. Mechanical endurance is listed at 10 million operating cycles typical. That's a high-cycle figure — expect this contactor to outlast the machine it's in for most conveyor, pump, and fan duty. The electrical life depends on the load category and switching frequency: AC-3 (motor) allows up to 1,000 operations per hour, AC-4 (plugging/inching) drops to 130 per hour. Arcing time is 10-15 ms, and the contactor's opening and closing times are 40-60 ms on both AC and DC. That's fast enough for most motor-starting sequences, but if you're timing a reversing starter, account for the full 60 ms closing plus the arc extinction before the second contactor engages. The auxiliary contact ratings at 24 V are 10 A, dropping to 0.3 A at 220 V. If you're switching a PLC input at 24 VDC, the 10 A rating is generous — the limiting factor is the PLC input's own current draw, not the contact rating. For 110 V control circuits, the 1 A rating still covers most relay and indicator loads.
Panel integration notes
The Size S6 frame measures 172 mm high by 120 mm wide by 170 mm deep. That depth of 170 mm is the dimension from the mounting surface to the farthest point of the contactor — verify your enclosure depth allows at least that plus the 20 mm forward clearance recommended for arc venting and wiring access. Clearance requirements: 10 mm upwards, 10 mm downwards, 10 mm at the side, and 20 mm forwards. The 10 mm side clearance is tight — you can mount contactors side-by-side on a DIN rail or screw-fixing bar with only 10 mm between them, which saves panel width. Main circuit accepts stranded wire 16-70 mm². Auxiliary terminals accept 2x (0.25 to 2.5 mm²) solid or stranded. Coil uses spring-type terminals.