The Siemens SENTRON 3VA1112-3EF36-0AG0 is a 3-pole molded case circuit breaker rated for 125 A continuous current (Iu) with a TM240 thermal-magnetic release, designed for line protection in distribution panels. It delivers 75.6 kA breaking capacity at 240 V and 52.5 kA at 415 V, so it handles high-fault utility feeds without cascading upstream. The breaker includes one auxiliary switch and one trip alarm switch (HP version) for remote status monitoring. Its latching endurance is rated at 15 000 operations.
Thermal derating and ambient limits
The 125 A rating holds flat from 40 °C to 50 °C, then derates to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. For a panel running at 60 °C ambient, expect to budget 117.5 A continuous — not the full 125 A. Operating range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.
Breaking capacity by voltage
Breaking capacity steps down with system voltage: 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 10.5 kA at 690 V. At 415 V it covers most European industrial mains; at 690 V it still clears 10.5 kA, enough for low-fault 690 V sub-distribution. Rated insulation voltage is 800 V.
Physical fit and panel integration
Dimensions: 130 mm high, 76.2 mm wide, 70 mm deep. The 76.2 mm width (roughly 3 inches) is a standard 3-pole MCCB footprint — fits existing SENTRON mounting rails and busbar systems. Front protection is IP40, so it is suited for enclosed distribution boards but not for washdown environments.