What the breaking capacity ratings mean for your panel
The 3VA1150-6EF36-0KC0 is a Siemens SENTRON 3-pole molded case circuit breaker (MCCB) rated for line protection. Its headline figure is the interrupting capacity: 220 kA at 240 V, dropping to 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 500 V and 690 V. That 220 kA at 240 V means it can safely clear a fault current up to 220,000 A at that voltage without welding contacts or rupturing — critical for high-fault panels near large transformers or in utility tie applications. The steep drop above 500 V tells you this breaker is optimized for low-voltage distribution (240–480 V systems), not 690 V feeders.
Thermal rating and derating curve
Rated 50 A continuous at 40 °C ambient, and it holds that 50 A all the way up to 50 °C — no derating needed in a warm panel. Above 50 °C it starts to pull back: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That's a gentle slope; you lose only 10 % of the rating from 40 °C to 70 °C, which is better than many MCCBs that start derating at 40 °C. If your enclosure runs hot (say 55 °C near a drive), you still get 49 A — enough for a 50 A feeder with a slight safety margin.
Built-in accessories: shunt trip and auxiliary switches
This variant ships with a shunt trip (STL) for remote tripping and two HQ auxiliary switches for status feedback — no field fitting needed. The shunt trip lets a PLC or safety relay kill the breaker remotely; the aux switches give you open/closed contacts for your control system. Insulation voltage is rated 800 V, which covers 480 V and 600 V class systems with headroom. Power loss at rated load is 14.6 W — modest for a 50 A frame, so it won't cook adjacent components in a dense panel.
Panel fit and dimensions
Footprint: 76.2 mm wide (3 in), 130 mm tall (5.12 in), 70 mm deep (2.76 in). That 70 mm depth means it fits standard 200 mm deep enclosures with room for wiring gutters. Three-pole, no undervoltage release, no ground-fault monitoring — this is a straight line-protection breaker with remote trip capability via the shunt trip. The supplied basic switch is 3VA11506EF360AA0.