What this 3VA1163-6GF46-0KF0 is and what it does
The Siemens 3VA1163-6GF46-0KF0 is a SENTRON molded case circuit breaker (MCCB) in the line protection version — meaning it's built for feeder and distribution duty, not motor-starting curves. Three poles, rated continuous current Iu of 125 A at 40 °C ambient, and holds that same 125 A all the way up to 50 °C before it starts to taper: 122 A at 55 °C, 120 A at 60 °C, down to 114 A at 70 °C. That's a solid thermal margin for a warm panel. Breaking capacity is where this one earns its keep: 76 kA at 240 V, 53 kA at 415 V, 32 kA at 440 V, and still 5 kA at 500 V and 690 V. For a 125 A frame, that 76 kA at 240 V gives you real selectivity headroom on a 240 V industrial service — you can coordinate downstream without cascading every fault upstream. The overcurrent release is a TM240 thermal-magnetic, so it's a fixed-trip breaker, no interchangeable rating plug. Rated insulation voltage Ui is 800 V, and max DC operational voltage is 500 V — useful if this lands in a battery or DC bus application. Front IP40 protection keeps dust out of the mechanism; fine for a clean panel but not washdown-rated. The auxiliary contact package is one auxiliary switch plus one trip alarm switch (HQ version), and it comes with a shunt trip (STL) integrated — part number 3VA9688-0BL33 for the trip coil itself.
Panel fit and integration notes
Height is 130 mm, width is 3 in — standard MCCB footprint for a 3-pole 125 A frame. Mounts on a DIN rail or panel-mount baseplate; no special cutout. The TM240 release is factory-set, so no field-adjustable thermal or magnetic dials — you spec the trip curve and it stays. Operating temperature range is -25 °C to 70 °C; storage from -40 °C to 80 °C. Mechanical endurance is 15,000 operations — fine for a distribution breaker that sees occasional switching, not a daily contactor replacement. No undervoltage release, no communication function, no ground-fault monitoring — this is a straight line-protection breaker with a shunt trip and auxiliary/trip alarm contacts. If you need remote monitoring or UVR, you're in a different variant. The trip indicator and voltage trigger are present, so you get local visual trip indication and a voltage-based trip signal.