It carries four normally-open main contacts and a 24 VDC coil that pulls in at 0.85 of rated voltage and holds at 3.3 W DC — no AC ripple to fuss with, just a clean DC hold. The contactor is rated 10 A in AC-12 duty (resistive loads) and 5.5 kW in AC-2 at 400 V, which covers wound-rotor motors and moderate inductive loads. The 24 VDC coil draws 3.3 W both during pickup and hold, so the control transformer sizing is straightforward — no inrush spike to over-spec for. Side-by-side mounting is allowed with a 6 mm gap for heat dissipation. The terminal block accepts solid or stranded wire up to 4 mm² (two conductors per clamp), and the IP20 finger-safe front and terminal covers keep live parts out of reach during panel access.
Switching capacity and coil details
The 3RT1317-1BE40 switches a range of control voltages beyond its 24 VDC coil: at 60 V it handles 2 A, at 110 V it handles 1 A, at 220 V it handles 0.3 A, and at 230 V it handles 6 A — these are the auxiliary contact ratings, not the main poles. The main contacts are strictly for the load side. For motor starting, the AC-2 rating at 400 V is 5.5 kW; for resistive heating or lighting circuits (AC-12), the maximum operating current is 10 A. Short-circuit protection is specified with type 1 and type 2 coordination: type 2 requires a 20 A gL/gG fuse, type 1 allows up to 35 A. That means in a coordinated starter assembly, you can size the upstream fuse to protect the contactor without welding the contacts on a fault. The coil's closing and holding power are identical at 3.3 W DC, which simplifies the DC supply sizing — no extra headroom for a pickup surge.
Environmental and installation limits
The IP20 rating on the front and terminals means it's finger-safe but not washdown-rated — keep it inside a sealed enclosure if there's hose-down or high-pressure spray.