The Siemens SENTRON 3VA1112-3EF32-0KC0 is a 3-pole molded case circuit breaker (MCCB) rated for 125 A continuous current, configured for line protection with a TM240 thermal-magnetic overcurrent release. It carries a shunt trip (STL) auxiliary release and two HQ auxiliary switches. Breaking capacity reaches 75.6 kA at 240 V, 52.5 kA at 415 V, and 32 kA at 440 V — figures that define the fault-clearing capability at the point of installation and drive coordination with downstream devices.
Rating and thermal behavior
The full 125 A rating holds from 40 °C through 50 °C ambient. Derating begins at 55 °C (120 A), dropping to 112.5 A by 70 °C. For a panel that runs warm — say a packed enclosure near a furnace line — that 12.5 A loss between 50 °C and 70 °C is the figure to budget. Rated insulation voltage Ui is 800 V.
Integration and auxiliaries
Dimensions: 130 mm high, 76.2 mm wide, 70 mm deep. Front protection is IP40 — sealed against tools and small wires, not washdown. The integrated shunt trip (STL) is ordered separately as 3VA9688-0BL33. No undervoltage release, no ground-fault monitoring, no communication module, no phase-failure detection. Two HQ auxiliary switches are fitted as standard, enough for status feedback to a PLC or a remote indication lamp.