The Siemens 3RB2026-2RB0 is a SIRIUS solid-state overload relay — a 3-pole device with CLASS 20E trip characteristic, designed for contactor mounting in any position. It protects motor circuits against overload and phase loss using a solid-state sensing circuit, not a bimetal strip, so it avoids the drift and ambient-temperature sensitivity of thermal relays. Rated for a 6 kV surge voltage and tested to 2 kV burst on power ports (severity level 3 per IEC 61000-4-4), it handles the electrical noise common in industrial panels. The ATEX Ex II (2) GD approval means it can be installed in the non-hazardous area protecting equipment in a Zone 1 or Zone 21 gas/dust environment — a common requirement for motor starters in chemical or grain-handling lines.
Fastens directly to a contactor (contactor mounting), saving DIN-rail space. Finely stranded wire with ferrule goes up to 2.5 mm² (2x 1.5 mm²). The 6 mm side clearance to grounded parts is the minimum air gap for the 6 kV surge rating — respect it during panel layout.