The Siemens 3VA1112-5EF36-0HH0 is a SENTRON 3VA1 molded case circuit breaker (MCCB) built for line protection in distribution panels. Rated 125 A continuously at 40 °C across all three poles, it handles the full current without derating up to 50 °C — above that it steps down to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. The 800 V rated insulation voltage (Ui) means it's comfortable on 480/600 V class systems with margin. Breaking capacity is the headline here: 187 kA at 240 V AC, 121 kA at 415 V, 75.6 kA at 440 V, and still 17 kA at 500 V and 690 V. That puts it in the high-interrupting category — suitable for transformer-fed main feeders or large motor control centers where fault current runs high. The 28.1 W maximum power loss matters for panel thermal budgeting if you're packing several breakers side by side.
Three-pole, 76.2 mm wide (3 inches), 130 mm tall, 70 mm deep — fits standard 3-pole MCCB mounting footprints in switchboards and panelboards. The auxiliary switch block comes factory-configured with 2 auxiliary switches plus 1 trip alarm switch (HQ type). A shunt trip (STL) is built in, no undervoltage release on this variant. The trip indicator is present for visual fault identification. Operating range is -25 °C to 70 °C ambient; storage from -40 °C to 80 °C.