The Siemens SIRIUS 3RB2016-1SD0 is a solid-state overload relay rated for CLASS 10E tripping. Three poles for the main current circuit, 45 mm wide, mounting directly onto a contactor. Main circuit terminals are screw-type (2× 0.25…1.5 mm² solid or 2× 18…14 AWG), auxiliary and control circuit terminals are spring-loaded (2× 0.25…1.5 mm² or 2× 24…16 AWG). The spring-clamp on the aux side saves wiring time in the panel — no screwdriver torque check needed. ATEX approval is listed: PTB 06 ATEX 3001 Ex II (2) GD.
Fastening method is contactor mounting — the relay snaps onto the front of a SIRIUS contactor. Dimensions: 73 mm deep, 45 mm wide, 64 mm high. The 0 mm clearances upwards, forwards, and backwards. Side clearance of 6 mm required. Shock resistance rated at 15g / 11 ms — fine for most industrial machinery, but if you're on a vibrating conveyor or press, check the contactor's own shock spec too.
Environmental & EMC
Operating temperature range -25…+60 °C, storage and transport -40…+80 °C. Relative humidity during operation up to 100% — condensing environment is allowed, but the enclosure must still be rated for the location. Surge voltage resistance rated at 6 kV; burst immunity per IEC 61000-4-4 at 2 kV on power ports and 1 kV on signal ports, severity level 3. That covers most industrial panel transients from contactor coils and drives.
Switching capacity (auxiliary contacts)
The relay has zero CO (changeover) auxiliary contacts built in — the number of CO contacts for auxiliary contacts is listed as 0. That means all signaling (trip alarm, manual reset) must come from an external auxiliary contact block or from the contactor's own aux. The rated switching capacities at various voltages are provided: at 24 V it handles 2 A, at 120 V 4 A, at 230 V 3 A, and at lower DC voltages (60 V, 110 V, 125 V, 220 V) the currents are 0.55 A, 0.3 A, 0.3 A, 0.11 A respectively. These values apply to the auxiliary circuit (spring-loaded terminals) — use them for selecting the interface to a PLC input or a pilot lamp.