Siemens SENTRON 3VA1150-3EF36-0KA0 — 50 A MCCB, Line Protection, 3-Pole
Breaking capacity is the headline spec here: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. For a 50 A frame, those are high-interrupting ratings — the 52.5 kA at 415 V means it can sit on a panelboard fed by a transformer with substantial fault current without needing a current-limiting fuse upstream. The 10.5 kA at 690 V is less common; it opens the door for 690 V industrial networks where most MCCBs in this frame size top out around 6 kA. Physical footprint: 70 mm deep, 76.2 mm wide, 130 mm tall. That 70 mm depth is shallow enough for a 200 mm deep enclosure with room for wiring gutters. The width at 76.2 mm is a standard 3-module DIN-rail pitch, so it fits a standard panel layout without custom bracketry.
Thermal Derating and Operating Range
The 50 A rating holds flat from 40 °C to 50 °C ambient. Above that, it derates: 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel ambient runs at 60 °C — common in a sealed enclosure with drives — you lose 3 A off the nameplate. The operating range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. That covers most indoor industrial environments, including unheated warehouses.
Configuration and Accessories
This variant ships without an auxiliary contact or undervoltage release. It does include a shunt trip (STL) as the auxiliary release — order code 3VA9688-0BL33 for the integrated trip unit. No communication function, no phase failure detection, no ground fault monitoring. It's a bare-bones line protection breaker: trip indicator is absent, so you'll need a remote indication via the shunt trip or a separate auxiliary contact block if that matters for your alarm scheme. IP40 on the front — fine for a closed panel, not for washdown or outdoor exposure without a secondary enclosure.