The Siemens SIRIUS 3RB3026-1QB0-ZX95 is a solid-state overload relay in the S0 size frame, rated for a thermal current of 25 A and a maximum operating voltage of 690 V. The relay mounts directly onto a contactor, not on a DIN rail, so panel layout needs to account for that direct coupling rather than a separate mounting footprint.
Trip indication and auxiliary contacts
This variant includes the "for message 'tripped'" designation, meaning the integrated auxiliary switch provides a dedicated signal contact that changes state when the relay trips. The auxiliary switch is rated for switching at various control voltages: 2 A at 24 V, 0.55 A at 60 V, 0.3 A at 110 V, 4 A at 120 V, 0.3 A at 125 V, 0.11 A at 220 V, and 3 A at 230 V. That covers most common PLC input voltages and relay coil supplies found in a panel. The shock resistance of the signaling contact in the tripped position is 9g / 11 ms per IEC 60068-2-27, so it holds its state under moderate vibration — useful if the panel is on a machine frame.
Storage and transport range is -40 to +80 °C. Vibration resistance per the evidence is 1-6 Hz at 15 mm amplitude and 6-500 Hz at 20 m/s² for 10 cycles — enough for general industrial use but not extreme continuous high-frequency vibration. Shock resistance for the main body is 15g / 11 ms. Mounting position is any, which helps when the contactor is mounted sideways or inverted in a tight enclosure.
Wiring and connection
Main circuit terminals accept screw-type connections: solid 1x (0.5 to 4 mm²) or 2x (0.5 to 2.5 mm²), and stranded up to 2x 10 mm². The screwdriver shaft diameter required is 5 to 6 mm with a Pozidriv PZ 2 tip. Main contact terminal screws are M4. The S0 size frame means the relay is 45 mm wide, 87 mm high, and 84 mm deep — compact enough for a standard motor starter assembly.