Line protection MCCB with TM240 release
The Siemens SENTRON 3VA1112-5EF32-0AE0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection duty, carrying 125 A continuous current and fitted with a TM240 thermal-magnetic overcurrent release. The TM240 designation means the thermal trip is fixed at 125 A (the frame rating) while the magnetic short-circuit pickup is adjustable — typical for feeder protection where you need selectivity downstream. Interrupting capacity is the headline here: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V is unusually high for a 125 A frame — it's sized for high-fault utility or transformer-fed secondary panels where SCCR requirements exceed typical distribution gear. Thermal derating is published across the full operating range: full 125 A rating holds from 40 °C through 50 °C, then steps down to 120 A at 55 °C, 117.5 A at 60 °C, 115 A at 65 °C, and 112.5 A at 70 °C. That's a shallow curve — only 10 % loss at the top end — so it handles crowded enclosures without aggressive downsizing.
Panel fit and integration
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that drops into SENTRON mounting bases and most DIN-rail adapter plates. Front protection is IP40, meaning tools and fingers are kept out, but the body is not sealed against washdown. The auxiliary contact block is populated with 4 HQ (high-amp) auxiliary switches — that's more than the typical 1NO+1NC config, so it can drive status LEDs, PLC inputs, and a shunt-trip monitor simultaneously without an add-on module. No undervoltage release, no shunt trip, no communication module, no ground-fault monitoring on this variant. The auxiliary release slot is empty — if you need UVR or shunt trip, you add them separately. Phase-failure detection is also absent; that's a different order code within the 3VA family.
Environmental and compliance
Storage temperature range is -40 °C to 80 °C; operating range is -25 °C to 70 °C. The storage maximum of 80 °C is the limit for warehousing and shipping, not running — don't leave it in a closed metal box in direct sun. Rated insulation voltage is 800 V, so this breaker is suitable for 690 V line-to-line systems with margin. The reference code per DIN EN 81346-2 is Q (power switching device).