The Siemens 3RU1116-0GB0-ZW97 is a SIRIUS thermal overload relay for motor protection, trip class 10, size S00, with three poles for the main current circuit. It mounts directly to a contactor or can be used as a standalone unit, and the mounting position is flexible — it can be rotated ±135° or tilted ±45° front/back on a vertical surface.
What the ratings mean for fit
Trip class 10 means the relay will trip within 10 seconds at a locked-rotor current of 7.2x the full-load setting — standard for general-purpose motor starting where the load doesn't have high inertia. The size S00 frame keeps the footprint compact: 45 mm wide, 87 mm tall, 78 mm deep, so it fits in tight panel layouts alongside the contactor. Screw-type terminals on both the main and auxiliary/control circuits accept solid conductors from 0.5 to 2.5 mm² (two per clamp) and stranded with ferrules in the same range. For AWG, the main terminals take 2x (20–16), 2x (18–14), and 2x 12. This covers standard motor lead and control wiring without needing adapters. IP20 on the front means it's protected against finger contact but not against moisture — fine for a dry indoor panel. The relay is ATEX approved (DMT 98 ATEX G 001) for use in potentially explosive atmospheres, so it can go into a motor starter feeding equipment in a hazardous area. Power dissipation is 1.6 W per pole, totaling 4.8 W for the three poles at full load. That's modest heat for a size S00 device, but in a densely packed panel with multiple relays side by side, the 6 mm side clearance to adjacent devices matters for keeping the ambient temperature within the -20 to +70 °C operating range. Surge voltage resistance rated at 6 kV means the relay can handle transient overvoltages common in industrial motor circuits without flashover — important for reliability on a line with frequent switching.
Mounting and integration
The 3RU1116-0GB0-ZW97 fastens via contactor mounting — it clips directly onto the matching SIRIUS contactor or can be screw-mounted on a DIN rail or panel. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. That zero-clearance on four sides means you can pack it tight against the contactor or enclosure wall, saving rail space. The auxiliary contact ratings cover common control voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, and 1 A at 400 V. These are the normally-open and normally-closed signal contacts for the PLC input or the contactor hold-in circuit.