The Siemens 3VA1110-3FF42-0AA0 is a 4-pole SENTRON molded case circuit breaker rated for 100 A continuous current (Iu) with a TM240 thermal-magnetic release — meaning the thermal element is fixed at 100 A and the magnetic pickup is set at 240 A, a common combination for feeder or distribution protection where you want a wide margin between full-load current and short-circuit trip threshold. Breaking capacity is the headline number that decides whether this breaker holds under fault: 76 kA at 240 V AC, 53 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. The 76 kA at 240 V gives headroom for high-fault panels close to the service entrance. Thermal derating is gradual: holds 100 A up to 50 °C ambient, then drops to 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, and 91 A at 70 °C.
Lifecycle and sourcing posture — active, not a legacy hunt
For a maintenance spares buyer, this is the kind of breaker you keep one in the cabinet for — it's a common 100 A 4-pole frame that backs up dozens of panel builds. The endurance rating of 20 000 operations (mechanical) gives a reasonable service life for a distribution breaker that sees infrequent switching.
Dimensions are 101.6 mm wide, 130 mm high, 70 mm deep — the 101.6 mm width is a standard 4-pole MCCB footprint (about 4 inches), so it drops into a DIN-rail or panel-mount base without surprises. No communication module on this version; it's a straight electromechanical breaker with no integrated metering or fieldbus.