Integrator's brief — SIRIUS 3RU7136-4GB0
The Siemens 3RU7136-4GB0 is a Size S2 thermal overload relay in the SIRIUS family, rated for a 45 A operational current at 690 V AC/DC, 50/60 Hz. CLASS 10 trip characteristic means it protects standard induction motor starts without nuisance tripping — the relay allows a 10-second locked-rotor heat rise before opening. Mounts directly onto the contactor (contactor mounting), not a standalone DIN-rail device. The relay's IP20 front and IP00 terminal area are standard for enclosed panel use — the terminals are live when open, so keep the panel door interlocked. Screw terminals on both main and auxiliary circuits, torque range 3–4.5 N·m for main contacts, 0.8–1.2 N·m for auxiliaries. Accepts 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²) solid or stranded wire with ferrules.
Mounting & integration notes
Fastens directly to a Size S2 contactor — no DIN rail adapter required. Mounting position allows ±135° rotation and ±45° tilt front-to-back on a vertical surface, which gives flexibility in tight cabinets. Side spacing to grounded parts: 6 mm minimum. Total typical power loss is 15.6 W at rated current in hot state. At 5.2 W per pole, factor that into enclosure thermal calculations — especially in sealed, non-ventilated panels. Dimensions: 118 mm depth × 55 mm width × 105 mm height. The 55 mm width matches the S2 contactor footprint — no extra panel width required.
Auxiliary contact ratings & environmental limits
Auxiliary contacts rated 3 A at 24 V and 2 A at 230 V; DC-13 at 24 V is 1 A. Surge voltage withstand is 6 kV. Operating temperature range –20 to +55 °C; storage/transport –25 to +70 °C. Humidity 0–90% RH non-condensing. Altitude limit 2000 m. Shock resistance 8g / 10 ms per IEC 60068-2-27 — adequate for most industrial floor vibration, but not rated for continuous high-shock environments like stamping presses without additional damping.