The 3RB2045-1EB0: Mounts directly onto a contactor — no DIN rail required, no extra bracket. The 70 mm width and 124 mm depth fit the standard SIRIUS contactor footprint. Side clearance is 6 mm; zero clearance needed above, below, or behind the unit. Screw-type terminals on both the main current circuit and the auxiliary/control circuit. Main terminals accept stranded wire from 10 to 70 mm² (or 2x 10 to 50 mm²), plus AWG 2x 10 to 1/0 or single 10 to 2/0. Auxiliary terminals take 0.5 to 4 mm² solid, or 2x 0.5 to 2.5 mm² stranded. That covers most motor-circuit wiring in a standard panel.
The ATEX marking (PTB 06 ATEX 3001 Ex II (2) GD) means it can be wired into the control circuit of an Ex-rated motor starter in a hazardous area; the (2) indicates it's associated apparatus, not installed inside the zone itself. The auxiliary contact ratings cover the common control voltages: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V — enough to drive a PLC input or a contactor coil directly. Power dissipation is negligible: 0.05 W total at rated AC hot state, 0.02 W per pole. That keeps the enclosure heat rise low even in a densely packed panel.
EMC and surge
Burst immunity per IEC 61000-4-4 at severity level 3: 2 kV on power ports, 1 kV on signal ports. Surge voltage resistance rated at 8 kV. That puts it in the 'industrial environment' class — no extra external suppression needed for most panel installations. The 100 % relative humidity rating during operation means it handles condensation-prone environments without conformal coating.