The Siemens 3RB2026-1PD0 is a SIRIUS solid-state overload relay — three-pole, Trip Class 10E, designed to mount directly onto a contactor. That Class 10E trip curve means it will trip within 10 seconds at 7.2× the set current, which is the standard match for standard-duty induction motors starting under load. It carries ATEX Ex II (2) GD approval, so it's cleared for use in potentially explosive atmospheres where gas or dust is present — the relay itself sits outside the hazardous zone but protects the motor inside it.
Mounting and fit
This relay fastens directly to the contactor — no DIN rail needed, no extra bracket. The footprint is 45 mm wide, 73 mm tall, 75 mm deep. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards, so it can sit tight against the contactor body. Side clearance is 6 mm. Mounting position is any orientation, which helps when you're squeezing it into a crowded panel. Main circuit terminals are screw-type; the auxiliary and control circuit terminals are spring-loaded — strip length for the spring terminals is 8 mm.
Electrical ratings and environment
Operating temperature range is -25 to +60 °C; storage and transport range is -40 to +80 °C. It handles 100 % relative humidity during operation — no derating for condensation as long as the enclosure is rated for it. Surge voltage resistance is 6 kV. EMC immunity includes 2 kV burst on power ports and 1 kV on signal ports, severity level 3 per IEC 61000-4-4. Shock resistance is 15 g for 11 ms. The auxiliary contact ratings cover a wide control voltage range: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V, and lower ratings at 60 V, 110 V, 125 V, and 220 V.