What it is and what the ratings mean
The Siemens SENTRON 3VA1112-6EF36-0AB0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, designed for line protection. Its 220 kA breaking capacity at 240 V means it can safely interrupt very high fault currents — typical for large transformer secondaries or heavy industrial feeders where upstream coordination demands a high SCCR. The TM240 thermal-magnetic release provides standard overload and short-circuit protection, with the thermal element tracking cable heating curves. Two HP auxiliary switches are built in for status feedback to a PLC or panel lamp.
Breaking capacity across voltages
The 3VA1112-6EF36-0AB0 delivers 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V. This steep derating above 440 V is typical for MCCBs with a fixed TM release — the arc extinction capability drops as voltage rises. For a 480 V panel, the 75.6 kA figure still covers most industrial service-entrance and feeder applications, but at 690 V the 17 kA limit means it's suited only for low-fault sub-distribution or motor branch circuits with known short-circuit current.
Thermal derating and operating range
Rated 125 A from 40 °C up to 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. If the panel ambient runs hot — say next to a drive cabinet or in a non-climate-controlled enclosure — the continuous current must be reduced accordingly. The operating temperature range is -25 °C to 70 °C, with storage from -40 °C to 80 °C. Maximum power loss is 28.1 W, which matters for enclosure heat-rise calculations when multiple breakers are ganged.
Panel fit and dimensions
The 3VA1112-6EF36-0AB0 measures 130 mm high, 76.2 mm wide, and 70 mm deep. The 76.2 mm width (3 inches) fits standard 3-pole MCCB mounting footprints in distribution panels. Depth of 70 mm is compact enough for shallow enclosures but leaves room for rear-connected busbars or cable lugs. No undervoltage release or ground-fault monitoring is included — those are separate accessories if needed.