Siemens 3VA1150-4EF36-0DC0 — SENTRON MCCB, 50 A, 75.6 kA at 415 V
The Siemens 3VA1150-4EF36-0DC0 is a 3-pole molded case circuit breaker from the SENTRON series, rated 50 A at 40 °C and delivering a breaking capacity of 75.6 kA at 415 V AC — enough to handle high-fault utility feeds in industrial distribution panels. It is designed for line protection (cable and busbar protection), not motor or generator protection, so the thermal-magnetic trip curve is set for overload and short-circuit on distribution circuits. The unit includes an undervoltage release (UVR) and two HQ auxiliary switches, which allow remote status feedback and undervoltage tripping without an external relay.
Breaking capacity and current ratings
Breaking capacity varies with system voltage: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V — the 415 V figure is the one most commonly specified for European 400 V distribution. Continuous current rating holds at 50 A from 40 °C through 50 °C, then derates to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C — the thermal limit in a warm cabinet matters if the breaker is enclosed without forced cooling. Insulation voltage is rated 800 V, and maximum power loss at rated current is 17.1 W — a modest thermal load for a DIN-rail or panel-mount enclosure.
Physical fit and environment
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that fits most Siemens SENTRON mounting bases and panel cutouts. Operating temperature range -25 °C to 70 °C, storage from -40 °C to 80 °C — suitable for unconditioned industrial enclosures.