The Siemens 3RB2026-1QB0-ZX95 is a SIRIUS solid-state overload relay — CLASS 10E trip curve, contactor-mount form factor, and ATEX Ex II (2) GD approval for potentially explosive atmospheres. It's rated for a 690 V AC-3 main circuit with screw-type terminals accepting 0.5 to 4 mm² solid or 2x 0.5 to 2.5 mm² stranded. The front face carries IP20; the relay itself mounts directly onto a contactor, saving DIN-rail space.
Trip class and thermal behaviour
CLASS 10E means the relay trips within 10 seconds at 7.2× the current setting — fast enough to protect a motor winding from locked-rotor heat without nuisance tripping on normal start-up. The solid-state design keeps power dissipation low: 0.05 W total at AC in hot operating state, or 0.02 W per pole. That's negligible heat for a panel; no derating for adjacent devices needed.
Mounting and clearances
Contactor mounting — clips onto the matching SIRIUS contactor without extra brackets. The relay body is 45 mm wide, 73 mm tall, 75 mm deep. Clearance to adjacent devices: 0 mm upwards, forwards, backwards, and downwards; 6 mm to the side. That zero-gap on four sides means you can pack relays tight in a row. Mounting position is any orientation. Operating temperature range is -25 to +60 °C; storage and transport -40 to +80 °C.
Environmental and compliance
Rated for 100 % relative humidity during operation — no condensation limit to watch. Shock resistance is 15g / 11 ms. Surge voltage withstand is 6 kV, with burst immunity per IEC 61000-4-4 severity 3 (2 kV on power ports, 1 kV on signal ports). The ATEX marking PTB 06 ATEX 3001 Ex II (2) GD covers gas and dust atmospheres; reference code per DIN EN 81346-2 is F. Pollution degree 3 rated for 690 V.