What it is and what it does
The Siemens 3RB2046-1EB0-ZX95 is a SIRIUS solid-state overload relay for three-phase motor protection. It provides Class 10E trip characteristics, meaning it will trip within 10 seconds at 7.2× the set current — fast enough to protect standard induction motors during a locked-rotor start, but without nuisance tripping on normal acceleration. The ATEX Ex II (2) GD approval means it can be used in the control circuit of a motor driving equipment in a gas or dust hazardous zone (the relay itself sits in the safe area, but its output contacts are part of the safety chain).
Mounting and wiring
Mounts directly onto a contactor via the contactor mounting fastening method — no DIN rail needed, which saves panel width. The body is 70 mm wide, 106 mm tall, and 124 mm deep, so it overhangs the contactor footprint slightly. Wire the main circuit with screw-type terminals accepting solid conductors from 0.5 to 4 mm² (or 2x 0.5 to 2.5 mm²) and stranded from 10 to 70 mm² (or 2x 10 to 50 mm²). For the auxiliary/control circuit, screw terminals accept 2x AWG 20 to 14. The auxiliary contact ratings are 2 A at 24 V, 4 A at 120 V, and 3 A at 230 V — enough to drive a PLC input or a contactor coil directly.
Environmental and electrical robustness
Rated for operation from -25 to +60 °C, with storage and transport down to -40 °C. Handles 100 % relative humidity (condensing) — fine for unheated enclosures in humid plants. Shock resistance is 15g for 11 ms, and surge voltage withstand is 8 kV. EMC burst immunity meets IEC 61000-4-4 severity level 3: 2 kV on power ports, 1 kV on signal ports. That means it won't false-trip from nearby contactor switching or VFD PWM noise on a typical industrial line.