The Siemens 3VA1125-4GF46-0AA0 is a SENTRON molded case circuit breaker with a 25 A rated continuous current and a TM240 thermal-magnetic release. Four poles, line protection version, no communication module. Breaking capacity hits 121 kA at 240 V and 76 kA at 415 V — that's the short-circuit current it can safely interrupt at those voltages without welding contacts or rupturing the case.
Breaking capacity and selectivity
At 240 V this breaker clears 121 kA; at 415 V it's rated for 76 kA. Those numbers drop to 53 kA at 440 V and 11.9 kA at 500 V or 690 V. For a panel engineer setting up a selective coordination study, the high 240 V figure means it can sit upstream of smaller branch breakers on a 240 V distribution and still maintain selectivity — the upstream breaker stays closed for faults the downstream device clears, as long as the let-through energy is within the downstream breaker's withstand.
Thermal derating and continuous current
Rated continuous current Iu is 25 A, and it holds that rating from 40 °C through 50 °C ambient. At 55 °C it derates to 24 A; at 65 °C it's 23 A. The TM240 release is a thermal-magnetic type — the thermal element tracks the load current and trips on sustained overload, the magnetic element handles instantaneous short-circuit protection. Insulation voltage rated at 800 V, max DC operational voltage 600 V.
Physical fit and panel integration
Dimensions: 70 mm deep, 101.6 mm wide, 130 mm tall. Four-pole width is standard for a 4P MCCB in this frame size. Front IP40 protection — suitable for enclosed panel mounting where the breaker face is behind a door or cover. Optional motor drive available for remote tripping or re-closing applications.
Operating environment
Operates from -25 °C to 70 °C ambient. Storage range is wider: -40 °C to 80 °C. Maximum power loss is 8.5 W — that's the heat dissipated at rated current, relevant for enclosure thermal calculations if the panel is tightly packed.