The Siemens 3RB2026-2PD0 is a SIRIUS solid-state overload relay, CLASS 20E, for 3-pole motor circuits. It mounts directly onto a contactor via the contactor mounting fastening method, saving DIN-rail space in the panel. The CLASS 20E trip class means it allows a longer start-up time for high-inertia loads like fans or conveyors before tripping, compared to a standard CLASS 10 relay.
The main current circuit uses screw-type terminals rated for 2x (14... 10) AWG, while the auxiliary and control circuit uses spring-loaded terminals rated for 2x (24... 16) AWG. That split means power wiring gets a secure screw clamp, while control wiring can be terminated faster with spring-cage insertion — no screwdriver needed for the aux side. Switching capacity varies by voltage: at 24 V it handles 2 A, at 120 V it handles 4 A, and at 230 V it handles 3 A. The 120 V figure (4 A) is the highest switching current across the listed voltages, so if your control voltage is 120 VAC, you get the most contact rating. At 220 V it drops to 0.11 A — a significant reduction, meaning at higher control voltages the relay is best used for signal-level switching, not power loads. Surge voltage resistance is rated at 6 kV, and burst immunity meets IEC 61000-4-4 severity 3 (2 kV on power ports, 1 kV on signal ports). The ATEX approval (PTB 06 ATEX 3001 Ex II (2) GD) certifies it for use in potentially explosive atmospheres — gas and dust — as an associated apparatus. That means it can be installed in the safe area and protect motor circuits in Zone 1 or Zone 21 locations, a common requirement in chemical, oil & gas, and grain handling plants.
Mechanical integration
That means it can be butted directly against adjacent devices in a row, saving panel space — only the side gap of 6 mm matters for heat dissipation and wiring access. Storage and transport range is -40 to +80 °C. The per-pole power dissipation is 0.02 W — negligible heat contribution inside the enclosure.
Substance prohibitance date per RoHS-like requirements is 07/01/2006. The product brand is SIRIUS, and the product designation is solid-state overload relay. No auxiliary CO contacts are provided (0 CO contacts) — any auxiliary signaling requires an external add-on module.