The Siemens SENTRON 3VA1150-3EF36-0CA0 is a 3-pole molded case circuit breaker (MCCB) rated 50 A at 40 °C, with a TM240 thermal-magnetic overcurrent release and an integrated undervoltage release. It's designed for line protection — meaning it sits at the feeder or branch level in a distribution panel, not as a motor-protective device. The interrupting ratings climb to 75.6 kA at 240 V, 52.5 kA at 415 V, and still hold 11.9 kA at 690 V, so it handles high-fault scenarios on 480Y/277 V or 400 V industrial services without cascading upstream.
What the interrupting ratings mean for your panel
The 75.6 kA at 240 V is the headline number, but the real-world decision point is the 52.5 kA at 415 V — that's the available fault current on a typical 400 V industrial service. If your transformer's impedance keeps the prospective short-circuit current under that, this breaker coordinates cleanly. The 11.9 kA at 690 V covers 600 V class installations (Canada, some mining) where fault currents are lower but voltage stress is higher. The 800 V rated insulation voltage (Ui) confirms the internal clearances handle that voltage class.
Thermal derating and power loss
The 50 A rating holds flat from 40 °C to 50 °C — no derating needed in a typical 40 °C panel ambient. Above that, it drops to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If your panel runs hot (enclosed, solar combiner, near a furnace), size the continuous load to the 70 °C figure, not the nameplate. Maximum power loss is 17.1 W per pole — three poles at full load dump about 51 W into the enclosure, so check your thermal budget if the panel is tightly packed.
Mounting and integration
The breaker measures 70 mm deep, 76.2 mm wide, and 130 mm tall — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without re-drilling. The undervoltage release (UVR) is built in, so if your safety circuit requires the breaker to trip on loss of control voltage, you don't need an add-on shunt trip. No communication function or ground-fault monitoring on this variant — it's a straight line-protection device with thermal-magnetic trip.