What this MCCB is and what it protects
The Siemens 3VA1050-3ED36-0AF0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — the primary role is guarding feeder and distribution circuits against overloads and short circuits in industrial switchboards and panelboards. Rated 50 A continuous at 40 °C, it holds that full rating through 50 °C before derating begins — at 55 °C it's 49 A, at 70 °C it's 45 A — so in a warm enclosure you still get nearly full ampacity. Breaking capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — these numbers tell you it can interrupt very high fault currents at the common low-voltage distribution levels, which matters when the available fault current at the panel is above 25 kA. At 500 V and 690 V the breaking capacity drops to 7.5 kA — still adequate for most motor control center (MCC) applications, but worth checking if your system has a high fault-current potential at those voltages.
Panel fit and integration
Three-pole, 70 mm deep, 76.2 mm wide, 130 mm tall — fits standard DIN-rail or direct-mount MCCB footprints used across SENTRON 3VA family panels. Rated insulation voltage 800 V, so it's suitable for 480/277 V and 600/347 V distribution systems common in North American and IEC panels. Power loss at full load is 14.6 W — plan for that heat in a sealed enclosure; it's not high for a 50 A MCCB, but it adds up in a multi-breaker lineup. Operating temperature range -25 °C to 70 °C, storage -40 °C to 80 °C — fine for most indoor industrial environments, including unheated warehouses.
Overcurrent release and auxiliary contacts
Comes with one auxiliary switch and one trip alarm switch (HQ type) factory-installed — gives you a remote status signal for the breaker position and a separate signal when it trips on fault. No undervoltage release, no shunt trip, no ground-fault monitoring — this is a bare line-protection breaker; add those externally if needed. Trip indicator (mechanical flag) visible on the front — lets a technician walking the panel see which breaker tripped without opening the door.
Lifecycle and sourcing reality
Listed as current production — no phase-out or last-time-buy notice on this code. Still a standard catalog item from Siemens.