What it is and where it fits
The Siemens 3RU1116-0HB0-ZX95 is a SIRIUS thermal overload relay — the part that sits between a contactor and the motor, watching current and tripping on sustained overload before the winding sees damage. Size S00 frame, so it mates directly with S00 contactors like the 3RT2 series without extra bracketry. CLASS 10 trip curve means it will open inside 10 seconds at 7.2× rated current, which is the standard for standard induction motor starting — no nuisance trip on a normal start, but fast enough to protect the motor on a stalled rotor. Mounts directly onto the contactor via the fastening method (contactor mounting), no DIN rail needed for the relay itself. The dimensions — 45 mm wide, 87 mm tall, 78 mm deep — keep it within the S00 envelope, and the IP20 front protection means it's safe for finger contact inside an enclosed panel. Clearance requirements: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. That zero-clearance spec simplifies panel layout — you can stack relays tight vertically.
Terminal details and wiring
Screw-type terminals on both main and auxiliary/control circuits. Main circuit accepts solid conductors: 2x (0.5...1.5 mm²) and 2x (0.75...2.5 mm²), plus AWG equivalents 2x (20...16), 2x (18...14), and 2x 12. Auxiliary contacts take 2x (20...16) and 2x (18...14) AWG. Finely stranded with core end processing follows the same cross-sections. That covers the common panel wire sizes — no need for ferrule adapters unless your shop standard calls for them.
Environmental and compliance
Rated for operation from -20 to +70 °C, storage and transport from -55 to +80 °C. 100 % relative humidity during operation — no derating needed for condensing environments. Shock resistance rated at 8g for 10 ms, which covers most industrial vibration profiles. Surge voltage resistance rated at 6 kV, giving solid margin for transient protection on 400 V line supplies. Carries ATEX approval (DMT 98 ATEX G 001) for use in potentially explosive gas atmospheres — the thermal model is certified for Ex e motor protection. The substance prohibitance date of 07/01/2006 aligns with RoHS compliance scope. Reference code per IEC 81346-2 is F (protective device).