What it is and what it does
The Siemens 3VA1050-3ED36-0AC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — the primary role is protecting cable and bus from overloads and short circuits in a distribution panel. It's a 3-pole unit rated 50 A continuous at 40 °C, with a TM210 thermal-magnetic release that handles the time-current curve for feeder circuits. The interrupting ratings climb to 75.6 kA at 240 V and 52.5 kA at 415 V, so it handles high-fault scenarios typical of industrial mains.
Interrupting capacity and thermal derating
The interrupting capacity drops as voltage rises: 32 kA at 440 V, then 7.5 kA at both 500 V and 690 V. That 7.5 kA at 690 V is the hard ceiling — if your fault current at that voltage exceeds it, step up to a higher-rated frame. Thermal derating is mild: the breaker holds 50 A all the way to 50 °C, then drops to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That means in a hot panel near the top of the ambient range you lose only 5 A — not enough to force a resizing for most circuits, but worth checking if you're running at the margin.
Panel fit and auxiliaries
The breaker measures 70 mm deep, 76.2 mm wide, and 130 mm tall — a standard 3-pole MCCB footprint that drops into a SENTRON panel or any DIN-rail-mounting distribution board. It ships with two auxiliary switches (HQ type) built in, so you get status feedback without an add-on module. No undervoltage release, no shunt trip, no ground-fault monitoring, and no communication function — this is a plain-vanilla line protection breaker. If you need those extras, you're looking at a different variant in the 3VA family.
Environmental range
Operating ambient spans -25 °C to 70 °C; storage range is wider at -40 °C to 80 °C. The insulation voltage is rated 800 V, so it's comfortable in 480 V and 600 V class systems. Maximum power loss at rated current is 14.6 W — negligible for panel heat budgeting unless you're packing dozens in a sealed enclosure.