SIRIUS S3 power contactor — 77 A at 480 V, spring-type coil terminals
The Siemens 3RT2045-3AF06 is a SIRIUS power contactor in size S3, rated for 77 A at 480 V in AC-3 duty — the motor-switching current that governs real-world sizing for pumps, conveyors, and compressors. The 77 A figure at 480 V means this contactor handles a 3-phase motor load up to roughly 55 kW at that voltage, though the exact motor FLA determines the fit. The main contact configuration is 10... 2 (normally open / normally closed count), and the coil terminals are spring-type, which speeds panel wiring versus screw-clamp variants.
The contactor measures 80 mm wide, 140 mm high, 152 mm deep. Solid conductor range is 2.5... 16 mm²; stranded accepts 6... 70 mm². Auxiliary switch is included.
Switching performance and operating conditions
Rated for 1 000 operating cycles per hour at AC-3 and AC-3e maximum. Arcing time is 10... 20 ms at AC. The contactor's typical mechanical life is 10 000 000 operations. Auxiliary contact ratings: 6 A at 24 V, 2 A at 48 V, 2 A at 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, 0.8 A at 440 V.