Siemens SENTRON 3VA1112-6MH36-0BH0 — 125 A MCCB with Starter Protection
The Siemens SENTRON 3VA1112-6MH36-0BH0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, designed specifically for starter protection — meaning it's built to coordinate with motor contactors and overload relays in motor control centers, not just as a feeder breaker. The interrupting rating hits 220 kA at 240 V and still delivers 154 kA at 415 V, so it handles high-fault utility feeds without cascading upstream.
Interrupting Capacity and Thermal Derating
The SCCR curve matters here: 220 kA at 240 V, 154 kA at 415 V, 75.6 kA at 440 V, and 7.5 kA at both 500 V and 690 V. That steep drop above 440 V tells you this breaker is optimized for 400 V-class systems (common in European and Asian industrial grids) — if your line runs at 480/500 V, the 7.5 kA rating still covers most transformer-fed faults but won't handle a direct utility tie without upstream current-limiting fuses. Thermal derating is gradual: 125 A holds steady from 40 °C through 50 °C, then drops to 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, and 114 A at 70 °C. That 11 A loss from 40 °C to 70 °C is tighter than many older MCCB families — useful if the panel runs warm near a drive stack or in a non-climate-controlled enclosure. Maximum power loss is 30.6 W at rated load, which factors into enclosure heat-budget calculations.
Dimensions and Panel Fit
The 3VA1112-6MH36-0BH0 measures 70 mm deep, 76.2 mm wide, and 130 mm tall. That 76.2 mm (3 in) width is the standard 3-pole MCCB footprint for this current class — it fits existing SENTRON 3VA panel cutouts and busbar layouts without adapter plates. Depth of 70 mm clears most 200 mm-deep enclosures with room for rear-connected busbars or cable ladders. Rated insulation voltage is 800 V, and the operating temperature range spans -25 °C to 70 °C, with storage from -40 °C to 80 °C. The trip indicator and undervoltage release are factory-integrated into the basic switch (order code 3VA11126MH360AA0), so the complete unit arrives as one assembly — no loose accessory kits to track.