Key Ratings and What They Mean for Fit
The 3RU1126-1KB0-ZX95: The Class 10 trip class means this relay will trip within 10 seconds at 7.2× the thermal current setting. This is the standard for standard-duty induction motor starting — it allows the motor to accelerate under load without nuisance tripping, but clears quickly on a stalled rotor. For motors with longer acceleration times (high-inertia loads like fans or centrifuges), a Class 20 or 30 relay would be required. The Size S0 frame is the most common Siemens overload relay footprint, designed for direct mounting to S0 contactors (e.g., 3RT1023 series). The 45 mm width and 97 mm height fit a standard DIN-rail or panel-mount layout; the 96 mm depth is the projection from the mounting surface, which must be accounted for in enclosure depth calculations. The main circuit terminals accept solid conductors: 2x (0.5... 1.5 mm²) and 2x (0.75... 2.5 mm²), with corresponding AWG ranges of 2x (16... 12) and 2x (14... 8). This covers the typical control wiring for motor circuits up to the S0 current range. The auxiliary/control circuit terminals accept 2x (20... 16) and 2x (18... 14) AWG. The surge voltage resistance rated at 6 kV, per the specification, ensures the relay withstands transient overvoltages common in industrial environments without insulation breakdown. This is a key parameter for panel builders verifying coordination with upstream surge protection devices.
Deployment Context and Integration
This relay mounts directly onto the contactor via the fastening method specified as 'Contactor mounting' — no additional DIN-rail adapter or bracket is needed for the S0 frame. The mounting position allows rotation of ±135° on a vertical surface and tilting of ±45° to the front and back, giving flexibility for tight panel layouts where the contactor is not perfectly upright. The IP20 protection on the front means it is protected against solid objects larger than 12.5 mm (fingers), but not against moisture ingress. This is standard for inside-cabinet installation; no washdown or outdoor rating is claimed. The 100 % relative humidity during operation rating confirms suitability for unconditioned enclosures in humid environments, as long as condensation is managed. The ATEX approval (DMT 98 ATEX G 001) permits installation in potentially explosive gas atmospheres, specifically for Group II equipment. This is a critical differentiator — not all SIRIUS overload relays carry this certification. For tender specifications requiring ATEX compliance, this variant satisfies that clause without an external interface module.
Lifecycle and Sourcing Reality
The substance prohibitance date of 07/01/2006 aligns with the EU RoHS compliance timeline. The part carries the reference code 'F' per IEC 81346-2, which designates a protective device in the classification system — useful for panel documentation and audit trails.
Environmental and Mechanical Limits
The operating temperature range is -20 to +70 °C, with storage and transport range extending to -55 to +80 °C. The shock resistance of 8g for 10 ms is typical for industrial control gear mounted in a panel on a machine subject to vibration. The clearance requirements are: 0 mm upwards, forwards, backwards, and downwards; 6 mm at the side. This zero-clearance design on five of six sides allows dense packing of contactor-relay pairs.