What it is and what it does
The Siemens 3RU1116-1CB0-ZW97 is a SIRIUS thermal overload relay — size S00, 3-pole, with screw-type terminals for main and auxiliary circuits. It provides Class 10 motor protection, meaning it trips within 10 seconds at 7.2× the set current, a standard match for standard induction motor starts (pumps, fans, conveyors) where the start-up transient is brief. The relay mounts directly onto a contactor (fastening method: contactor mounting), saving DIN-rail space in a panel.
Key ratings and what they mean for fit
Trip Class 10 is the headline here — it governs the overload curve. For a motor that accelerates in under 10 seconds (most IEC standard motors up to about 15 kW), this relay clears without nuisance tripping. The auxiliary contact ratings are given at multiple control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V — so the signal circuit can be wired into a 24 VDC PLC input or a 120 VAC control loop without derating surprises. The relay carries ATEX certification (DMT 98 ATEX G 001), which means it is approved for use in potentially explosive gas atmospheres — a requirement for Zone 1 or Zone 2 motor circuits in chemical or oil & gas plants.
Panel fit and mounting
Dimensions are 45 mm wide, 87 mm high, 78 mm deep — a compact S00 footprint that clips onto a contactor without extra DIN-rail slots. The mounting position allows ±135° rotation on a vertical surface and ±45° tilt front-to-back, so it fits in tight enclosures or angled sub-panels. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. That means it can be packed tight against adjacent devices on the same contactor rail, as long as side breathing space is held. IP20 on the front means finger-safe touch protection; the rest of the relay is open to the panel environment, so it belongs in a clean, dry cabinet — not a washdown zone.
Compliance and approvals
The relay carries ATEX certification (DMT 98 ATEX G 001) for explosive gas atmospheres. It is RoHS-compliant (substance prohibitance date 07/01/2006). The reference code per IEC 81346-2 is F (protective device). Surge voltage resistance rated at 6 kV. Relative humidity tolerance during operation is 100 % — suitable for condensing environments inside a sealed panel. The protection class on the front is IP20, finger-safe.