Line protection breaker with shunt trip — 125 A continuous, 187 kA interrupting
The Siemens SENTRON 3VA1112-5EF36-0HA0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, designed for line protection in distribution panels. Its TM240 thermal-magnetic overcurrent release provides fixed thermal and magnetic trip settings for overload and short-circuit protection, with a shunt trip (STL) auxiliary release for remote tripping. Breaking capacity reaches 187 kA at 240 V, 121 kA at 415 V, and 75.6 kA at 440 V — high enough for most industrial service-entrance or feeder applications where fault currents are substantial. Rated insulation voltage is 800 V, and the breaker dissipates 28.1 W maximum at rated load.
Thermal derating and ambient limits
The 125 A rating holds flat from 40 °C through 50 °C, then derates to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. Operating ambient range is -25 °C to 70 °C; storage range is -40 °C to 80 °C. Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that fits most DIN-rail or panel-mount enclosures without re-drilling.