What it is and what the ratings mean for fit
The Siemens SENTRON 3VA1050-3ED36-0BA0 is a 3-pole molded case circuit breaker (MCCB) rated 50 A at 40 °C, designed for line protection in distribution panels and motor control centers. The TM210 thermal-magnetic release handles overload and short-circuit protection — the thermal element tracks load current, the magnetic element trips instantaneously on high fault currents. An undervoltage release (UVR) is integrated, so the breaker can be tripped remotely or by a safety circuit when control voltage drops below the dropout threshold. The 75.6 kA breaking capacity at 240 V and 52.5 kA at 415 V mean it safely interrupts faults up to those levels without cascading upstream — critical for high-fault-current installations like industrial mains or transformer secondaries. The rated insulation voltage of 800 V confirms it is suitable for 690 V systems with margin. Dimensions of 130 mm height, 76.2 mm width, and 70 mm depth fit standard panel cutouts; depth is the dimension to watch when the breaker sits behind a gland plate or in a shallow enclosure.
Thermal derating and operating range
The breaker holds its 50 A rating from 40 °C through 50 °C ambient. Above that, derating is linear: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. In a sealed panel or high-ambient motor room, use the 55 °C or 60 °C column to size the breaker for continuous load — the 50 A nameplate applies only when ambient stays at or below 50 °C. The operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C, so the breaker survives cold warehouses and hot shipping containers without damage.
Breaking capacity across voltage levels
The breaking capacity varies by system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 7.5 kA at both 500 V and 690 V. The steep drop above 440 V means the breaker is not suitable for high-fault 690 V mains without coordination study — the 7.5 kA figure may be adequate for transformer-fed sub-distribution but not for direct connection to a high-capacity 690 V bus. For 400 V class systems (common in European industrial), the 52.5 kA at 415 V provides generous headroom for most installations.
Integration notes
The 70 mm depth is the critical dimension when the breaker is mounted in a panel with a gland plate or behind a door — standard 100 mm deep enclosures leave 30 mm for wiring and bus bars. The 76.2 mm width (3 inches) matches the standard SENTRON 3VA footprint for 3-pole breakers, so it drops into the same cutout as other 3VA frames. The undervoltage release is factory-fitted; no field assembly required. The TM210 release is non-interchangeable — the breaker is ordered as a complete unit. Power loss at rated current is 17.1 W, which should be factored into enclosure thermal calculations when multiple breakers are ganged.