Thermal Overload Relay, Size S00 — CLASS 10, ATEX Rated
The Siemens 3RU1116-1HB0-ZW97 is a SIRIUS brand thermal overload relay (product designation per) in size S00. The part carries ATEX certification DMT 98 ATEX G 001, confirming suitability for use in potentially explosive atmospheres — per IEC 60079, this marking covers Group II gas environments. Mounts directly to a contactor via the fastening method, saving DIN-rail space in the panel.
For conveyors or pumps with longer acceleration, CLASS 10 is the correct choice; for high-inertia loads you would step to CLASS 20 or 30. The 3 poles for the main current circuit match a standard three-phase motor. Power loss per pole is 2.2 W, so total dissipation in the enclosure is about 6.6 W under full load — factor that into your panel thermal budget. Surge voltage resistance rated at 6 kV gives the relay a solid coordination level for industrial mains with moderate transient exposure.
Mounts on the contactor, not on DIN rail directly. The mounting position allows ±135° rotation and ±45° tilt front/back from a vertical surface — confirm orientation clearance in your enclosure layout. Dimensions: 45 mm width, 87 mm height, 78 mm depth. Clearances required: 0 mm upwards, 0 mm forwards, 0 mm backwards, 0 mm downwards, but 6 mm at the side for air circulation and arc flash separation. Operating temperature range -20 to +70 °C; storage and transport -55 to +80 °C. Shock resistance rated at 8g for 10 ms — adequate for most industrial panels but verify if mounting on a vibrating machine frame. Relative humidity during operation up to 100 % — no derating needed for condensing environments.
Solid wire capacities for main contacts: 2x (0.5... 1.5 mm²), 2x (0.75... 2.5 mm²), and 2x 12 AWG. For auxiliary contacts: 2x (20... 16 AWG) and 2x (18... 14 AWG). Finely stranded with core end processing: same as solid. Use ferrules on stranded conductors for reliable termination. The auxiliary contact ratings are given at multiple voltages: 1 A at 24 V, 3 A at 120 V, 2 A at 230 V, 1 A at 400 V, plus control-circuit values at 110 V (0.22 A,), 125 V (0.22 A,), and 220 V (0.11 A,) — these govern the signal load you can switch through the relay's auxiliary contact block.