What it is and where it lands
The Siemens 3RT1015-1AH01 is a SIRIUS power contactor in the S00 frame size, rated for 10 A in AC-12 duty (resistive loads at line frequency). It's a panel-mount component designed for screw-and-snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022 — the standard DIN rail found in every industrial enclosure. The 24 V DC coil makes it a direct fit for PLC-controlled panels running a 24 VDC control bus.
What the ratings mean for fit
AC-12 at 10 A covers resistive loads like heaters and incandescent lamps; if you're switching motor loads, the AC-3 rating is what governs — and that's where the S00 frame typically lands around 5.5 kW at 400 V. The AC-4 rating at 6.5 A at 400 V tells you the contactor can handle reversing or inching duty with motor loads, which cycles the contacts harder than across-the-line starting. Pollution degree 3 means it's rated for the conductive-dust and humidity environment typical of industrial control panels — not clean-room or residential. DC switching is where this part earns its keep in mixed-load panels: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, and 6 A at 230 V AC. That DC curve matters when you're breaking solenoid valves or DC brake coils — the arc doesn't self-extinguish the way AC does, so the contact gap and material are designed for it. Side-by-side mounting is allowed with 6 mm spacing between contactors, which keeps the panel dense. The screw terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²) — fine for control wiring up to 4 mm² for short power runs. IP20 on the front and terminals means finger-safe but not washdown; keep it inside a closed cabinet.
Coordination and protection
For Type 1 coordination (no damage to the contactor but contacts may weld under fault), the required upstream fuse is gL/gG 35 A. For Type 2 coordination (contactor remains operational after a fault), it's gL/gG 20 A. That's the difference between a nuisance trip that clears and a blown contactor that needs replacement — specify the right coordination class for your maintenance strategy.
Mechanical endurance and environment
Rated for 30 million mechanical cycles typical — that's the unloaded life. Electrical life depends on the load current and duty cycle, but the mechanical figure tells you the coil and armature assembly are built for high-frequency cycling in applications like conveyor indexing or packaging machinery. Operating temperature range is -25 to +60 °C, which covers most indoor industrial environments without derating.