What it is and what it does
The Siemens 3RT1016-1AR05 is a SIRIUS power contactor in the S00 frame size — the smallest in the series, built for 45 mm DIN-rail mounting. It's a three-pole contactor with screw-type terminals, rated for switching motor loads under AC-2 duty at 4 kW on a 400 V line. The coil is rated for 415 V at 50 Hz and 415 V at 60 Hz, so it's a straight 400 V class coil — common across European and Asian 400 V three-phase systems. The contactor holds in down to about 0.8x rated voltage at 50 Hz and 0.85x at 60 Hz, giving some brownout margin. AC-2 duty at 4 kW means it's sized for slip-ring motors or other loads where the contactor makes and breaks under load but not at locked-rotor current. For more severe switching (AC-4, reversing, plugging), it's rated 8.5 A at 400 V — that's the number to watch if you're jogging or inching the load.
Mounting and panel fit
Screw and snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022. The 45 mm width means it occupies one standard 45 mm slot on the rail — no surprises for panel layout. Side-by-side mounting is permitted, so you can gang multiple contactors without extra spacing. Depth is 114 mm, height 57.5 mm. That depth includes the coil terminals and arc chambers, so account for it against the back panel or enclosure door. IP20 on the front and at the terminals — finger-safe but not washdown-rated; keep it inside a cabinet. Operating temperature range is -25 to +60 °C, with pollution degree 3 — suitable for industrial environments where conductive dust or condensation is present. The 2000 m maximum altitude rating covers most installations without derating.
Wiring and coordination
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) — solid or stranded. AWG equivalents are 2x (20 to 16), 2x (18 to 14), and 1x 12. That's enough for the main circuit wiring on a 4 kW motor; the terminals are rated for 10 A continuous at AC-12 (resistive). For short-circuit protection, Type 2 coordination (no damage to the contactor) requires a gL/gG fuse rated 20 A. Type 1 coordination (contactor may need replacement after fault) allows a 35 A fuse. The 20 A limit is the one to design to if you want to avoid replacing the contactor after a fault. Auxiliary contacts: the listing shows 1 N/O + 1 N/C instantaneous contact block. That's the standard single-deck block for feedback or interlocking. The contactor has a mechanical life of 30 million operations typical — that's the figure for the main contacts under light load; derate for AC-3/AC-4 duty.
Lifecycle and sourcing
For a BOM freeze or a line-down replacement, this contactor is quoted to order against an RFQ. The 45 mm footprint and screw terminals are common across the S00 family, so if you're swapping in a panel that was built around a different S00 variant, the mechanical fit is the same — just verify the coil voltage and auxiliary contact configuration.