Part identification and design intent
The Siemens SENTRON 3VA1080-4ED36-0BC0 is a 3-pole molded case circuit breaker (MCCB) configured for line protection. It carries 80 A continuous current at 40 °C, with the TM210 thermal-magnetic release providing overload and short-circuit protection. An undervoltage release (UVR) is factory-fitted, and two HQ auxiliary switches are integrated for status feedback to a PLC or safety circuit.
Breaking capacity and selectivity
Breaking capacity is rated at 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at 690 V. These figures define the fault-clearing capability at the respective system voltages — important for selectivity studies and SCCR compliance in a distribution panel.
Thermal derating and ambient limits
The breaker holds full 80 A rating through 50 °C. Above that, current must be derated: 76.8 A at 55 °C, 75.2 A at 60 °C, 73.6 A at 65 °C, and 72 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. The derating curve governs panel fill factor and spacing — a tightly packed enclosure with elevated internal temperature will require a larger frame or forced ventilation.
Mounting and panel integration
Dimensions are 130 mm height, 76.2 mm width (roughly 3 inches — fits standard 3-pole MCCB footprint), and 70 mm depth. Front protection is IP40. The 3VA frame mounts via screw-clamp to a backplate or DIN rail adapter (not integrated). The undervoltage release coil and auxiliary switch wiring terminate on the front-accessible terminals; verify free-wheel diode polarity on the UVR if driven by a PLC digital output.