What it is and what it does
The Siemens 3VA1050-3ED32-0BA0 is a SENTRON molded case circuit breaker (MCCB) rated for 50 A continuous current at 40 °C, with a TM210 thermal-magnetic overcurrent release. It's a line-protection device — meaning it guards cables and busbars against overloads and short circuits, not a specific motor or load. The 3-pole construction handles three-phase circuits up to 800 V rated insulation voltage. Breaking capacity runs from 75.6 kA at 240 V down to 7.5 kA at 690 V — that's the fault current it can safely interrupt without welding its contacts or blowing apart. At 415 V (common industrial distribution voltage) it's rated 52.5 kA, which covers most panelboard and switchboard applications.
Key ratings and what they mean for fit
The 50 A continuous rating holds steady from 40 °C up to 50 °C — no derating needed in a warm enclosure. It only starts to drop at 55 °C (48 A) and goes to 45 A at 70 °C. That's a solid thermal curve for a panel sitting next to drives or transformers. This MCCB includes an undervoltage release (UVR) — the 3VA9608-0BB11 integrated auxiliary trip. That means if the control voltage drops below a threshold, the breaker trips open. Common on safety circuits or where you need loss-of-voltage protection. No auxiliary contacts, no communication module, no ground-fault monitoring on this variant. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep — a standard 3-pole MCCB footprint that fits SENTRON panelboards and most DIN-rail adapter plates. Front IP40 protection keeps dust out of the enclosure face.