What this MCCB is and what it protects
The Siemens SENTRON 3VA1050-2ED32-0BA0 is a 3-pole molded case circuit breaker (MCCB) designed for line protection — meaning it guards cables and distribution feeders against overloads and short circuits, not motor or generator circuits. It carries a TM210 thermal-magnetic overcurrent release (fixed thermal, fixed magnetic) and includes an integrated undervoltage release (UVR) that trips the breaker when supply voltage drops below a set threshold, a common requirement for safety disconnects in industrial panels.
Current rating and thermal derating
Rated 50 A continuous at ambient temperatures up to 50 °C, with no derating needed in that range. Above 55 °C the current must be reduced: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel runs hot — near the 70 °C operating maximum — the breaker still holds 45 A, which is useful in sealed enclosures or high-density DIN-rail layouts.
Breaking capacity across voltages
Short-circuit breaking capacity varies sharply with system voltage: 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. For a 400 V distribution panel (common in European industrial lines), the 32 kA rating covers most secondary distribution scenarios. At 690 V the 7.5 kA figure is modest — verify the available fault current at the point of installation before specifying.
Panel fit and dimensions
Width 76.2 mm (3 in), depth 70 mm (2.76 in), height 130 mm (5.12 in). The 3-pole footprint is standard for SENTRON 3VA MCCBs; it mounts on a DIN rail or directly to a backplate. The undervoltage release adds a small wiring step — confirm polarity and coil voltage from the nameplate before energizing.