What it is and where it fits
The Siemens 3RU1116-1EB0-ZW95 is a SIRIUS thermal overload relay in the compact Size S00 frame, designed for three-phase motor protection in control panels. It mounts directly onto a contactor — the fastening method is contactor mounting — so it shares the same DIN-rail footprint as the contactor it pairs with. Trip Class 10 means it will trip within 10 seconds at 7.2× the full-load current setting, which is the standard for standard-duty induction motor starting — adequate for most pump, fan, and conveyor applications that do not have prolonged acceleration times.
Key ratings and what they mean for fit
The relay is rated for 3 poles and carries screw-type terminals on both the main and auxiliary circuits. The solid wire acceptance is 2× (0.5... 1.5 mm²) and 2× (0.75... 2.5 mm²), and the finely stranded with core-end-processing range is identical. For AWG auxiliary contacts, it accepts 2× (20... 16) and 2× (18... 14). These are typical ranges for a Size S00 device — expect to land up to 2.5 mm² on the power side. Auxiliary contact ratings are specified across multiple control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. At 110 V and 125 V the rating is 0.22 A; at 220 V it is 0.11 A. These are the switching capacities for the built-in auxiliary contacts — important for verifying that the control circuit load (PLC input, pilot relay coil) does not exceed these limits. Power dissipation per pole is 1.9 W, so for a three-pole relay under full load the total heat is about 5.7 W. This is modest and typically does not require forced cooling in a standard IP20 enclosure, but it should be accounted for in the panel thermal budget. The front face carries IP20 protection, which is finger-safe but not sealed against moisture ingress — this is a dry-panel device, not rated for washdown environments.
Installation and environmental constraints
Mounting position is flexible: the relay can be installed on a vertical mounting surface, rotatable ±135° and tiltable ±45° to the front and back. This helps when routing wires in a crowded panel. Clearance distances are specified: 0 mm upwards, forwards, backwards, and downwards, and 6 mm at the side. This means the relay can be mounted flush against other components vertically, but needs 6 mm side clearance — typical for Size S00 devices. Operating temperature range is -20 to +70 °C; storage and transport range is -55 to +80 °C. The relay is rated for 100 % relative humidity during operation, which is acceptable for non-condensing environments. Shock resistance is 8g for 10 ms, and surge voltage withstand is 6 kV.
ATEX and compliance
This relay carries ATEX approval for explosive atmospheres, identified by the protection type DMT 98 ATEX G 001. That means it is certified for use in gas-group applications per the ATEX directive — a critical check for oil and gas, chemical, or grain-handling installations where a standard thermal overload relay would not be permitted.