SIRIUS S3 power contactor — 3RT1044-3AF06
The Siemens 3RT1044-3AF06 is a SIRIUS S3 power contactor rated for motor switching up to 37 kW at 500 V (AC-3) and 55 A in AC-4 duty at 400 V — the AC-4 figure governs reversing or inching applications where the contactor makes and breaks stalled rotor current, so that 55 A is the rating that matters for jogging or plugging duty cycles. The main current circuit uses screw-type terminals accepting solid conductors 2x (0.25…2.5 mm²) and stranded 2x (10…50 mm²), with an additional solid/stranded range of 2x (2.5…16 mm²) — covering both control wiring and power cable sizes typical for S3 frame contactors.
Envelope and protection
The contactor body carries IP20 on the front with a cover or box terminal; the terminal itself is IP00.
Rated operating frequency reaches 1 000 switching cycles per hour at AC-1 and AC-3, 400 at AC-2, and 300 at AC-4 — the AC-4 limit reflects the thermal stress of breaking locked-rotor current. Arcing time spans 10…15 ms, with an additional AC arcing window of 10…19 ms. The coil operates at 50 Hz with a voltage tolerance of 0.8…1.1 times the rated value. Auxiliary contact ratings at 24 V are 10 A, stepping down to 0.3 A at 220 V and 6 A at 230 V — these figures determine the pilot-duty capability for PLC or relay interface circuits.
The substance prohibitance date of 05/01/2012 aligns with RoHS compliance — the part meets the EU RoHS directive effective from that date.