The Siemens 3RU1116-1CB0-ZW95 is a SIRIUS thermal overload relay in Size S00, a 3-pole unit with screw-type terminals for the main and auxiliary/control circuits. It's Trip Class 10, meaning it will trip within 10 seconds at 7.2× the set current — standard for protecting standard induction motors during start-up without nuisance tripping on normal acceleration.
What the ratings mean for fit
Size S00 is the smallest frame in the SIRIUS overload relay family, designed to mount directly onto S00 contactors. The 45 mm width and 87 mm height keep it compact for dense panel layouts; the 78 mm depth is the dimension you need to check against enclosure depth and wiring duct clearance. The screw terminals accept solid conductors 2x (0.5... 1.5 mm²) and 2x (0.75... 2.5 mm²), plus the equivalent AWG ranges. That covers most motor control wiring up to about 2.5 mm² per pole — typical for fractional to small integral-horsepower motors. IP20 on the front means finger-safe from the panel face, but the relay itself is not sealed against dust or moisture ingress — it belongs inside a cabinet, not in a washdown zone. Mounting position is flexible: vertical surface with ±135° rotation or ±45° tilt front-to-back. That covers most panel orientations without derating, but the 0 mm clearance requirements upwards, forwards, and backwards mean it can sit tight against other components — only 6 mm needed at the side for airflow.
Integration notes
Fastening method is contactor mounting — it snaps directly onto the matching S00 contactor (e.g., 3RT201 or 3RT202 series), no DIN rail adapter needed. The relay and contactor become a single assembly that clips onto the DIN rail as a unit. Shock resistance rated at 8g / 10 ms, which is adequate for most industrial panel environments including conveyor systems and machine tools. The surge voltage resistance of 6 kV covers the typical transient environment in 400 VAC industrial networks. Power dissipation per pole is 1.9 W, so 5.7 W total for the three poles at full rated current. That's modest, but in a sealed, densely packed panel with multiple relays, the cumulative heat needs consideration — the 6 mm side clearance is the minimum for natural convection.