What it is and what it switches
The Siemens SIRIUS 3RT1015-2AN22 is a size S00 power contactor, designed for switching motor loads in control panels. It's rated for 3.5 kW at 500 V and 4 kW at 690 V, with an AC-2 rating of 3 kW at 400 V for slip-ring motors. The 24 VDC coil pulls in at 10 A, so check your control transformer sizing — that's the inrush, not the hold. Termination is via spring-loaded terminals, accepting 2x (0.25 to 2.5 mm²) solid or stranded. That's a clean, vibration-resistant connection — no screw torque to verify, just strip to 8 mm and push in. The front face carries IP20, so it's protected against accidental finger contact in the panel.
Mounting and panel fit
Mounts via screw or snap-on to a 35 mm DIN rail per EN 50022. The 45 mm width and 60 mm height fit standard S00 footprint. Side-by-side mounting is allowed with zero clearance — no derating needed for adjacent contactors at rated load, as long as ambient stays within -25 to +60 °C. Depth is 73 mm, so factor that into gland-plate clearance and door swing. Pollution degree 3 means it's rated for conductive environments — typical in industrial panels where some dust and humidity are present.
Coordination and protection
For Type 2 coordination (no damage to the contactor on a short circuit), Siemens specifies a gL/gG fuse rated at 20 A. For Type 1 coordination (contactor may need replacement after fault), use a 35 A fuse. The AC-4 rating at 400 V is 6.5 A — that's the reversing or plugging duty cycle, so if you're doing frequent starts under load, this is the number to watch.