What it is and what it does
The Siemens SIRIUS 3RT1016-2AP04-3MA0 is a size S00 power contactor for switching motor loads in control panels. Its AC-2 rating of 4 kW at 400 V covers slip-ring motor duty; the AC-4 rating of 8.5 A at 400 V handles reversing and inching applications where the contactor makes and breaks stalled-rotor current. The spring-loaded terminals on the main current circuit accept 2x (0.25 to 2.5 mm²) solid or stranded wire, which speeds wiring in high-density panels.
Mounting and integration
Mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width and 60 mm height fit the S00 footprint; depth is 114 mm. Side-by-side mounting is permitted, so you can gang multiple contactors without extra spacing. IP20 protection on the front and terminals means it's suited for enclosed panels where no washdown or dust ingress is expected.
Key ratings and what they mean
The AC-2 rating (4 kW at 400 V) is the duty for slip-ring motors where the contactor closes on a running load — the real-world figure for most wound-rotor applications. The AC-4 rating (8.5 A at 400 V) governs plugging and inching cycles; if your machine reverses or jogs frequently, this is the number that determines contactor life. Operating temperature range of -25 to +60 °C covers most indoor panel environments without derating.