Siemens SENTRON 3VA1125-3GD42-0AA0 — 25 A 4-Pole MCCB, Line Protection
The Siemens SENTRON 3VA1125-3GD42-0AA0 is a 4-pole molded case circuit breaker rated for 25 A continuous, designed for line protection in distribution panels. Its TM210 thermal-magnetic release handles overload and short-circuit conditions without external trip units. The interrupting capacity hits 75.6 kA at 240 V and 52.5 kA at 415 V — enough for most industrial service-entrance or feeder applications where high fault current is expected.
Interrupting Capacity and Selectivity
At 240 V the breaker clears 75.6 kA; at 415 V it handles 52.5 kA; at 440 V it drops to 32 kA, and at 500 V or 690 V it holds at 11.9 kA. That 75.6 kA figure at 240 V makes it a strong candidate for high-fault panels in North American 240/120 V split-phase or 240 V delta services. The 52.5 kA at 415 V covers most European 400 V three-phase mains. Rated insulation voltage is 800 V, so it's comfortable in 690 V systems as long as the interrupting capacity at that voltage is respected.
Thermal Derating and Ambient Performance
The breaker carries its full 25 A rating from 40 °C through 50 °C. At 55 °C it derates to 24 A, holds there through 60 °C, then drops to 23 A at 65 °C and 70 °C. That's a shallow derating curve — only 2 A lost over a 30 °C rise — so it's well suited for sealed enclosures or high-ambient panel rooms where other breakers would need a larger frame. Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Mounting and Panel Fit
The 3VA1125-3GD42-0AA0 measures 70 mm deep, 101.6 mm wide, and 130 mm tall. That 101.6 mm width (4 inches) is standard for a 4-pole MCCB in this frame size — it occupies four 25 mm pole positions on a DIN rail or panel-mount footprint. Front protection is IP40, so it's fine for indoor panel use but not washdown. No undervoltage release, no communication module, no ground-fault monitoring — this is a straight line-protection breaker with the TM210 release only.