What it is and what it does
The Siemens 3VA1180-5EF32-0BC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection — the primary feeder breaker in a distribution panel or the main disconnect for a motor control center. It's a 3-pole unit rated 80 A continuously at 40 °C, meaning it carries that load without tripping in a typical 40 °C panel ambient. The interrupting rating of 187 kA at 240 V AC is the key number for fault clearing: this breaker can safely interrupt a short-circuit fault up to that level without welding contacts or rupturing the case, which is essential for high-fault installations close to a large transformer.
Ratings and what they mean for fit
The continuous current derating curve is published: 80 A from 40 °C through 50 °C, then 78 A at 55 °C, 77 A at 60 °C, 75 A at 65 °C, and 74 A at 70 °C. If your panel runs hot — say 55 °C inside — you need to account for that 2 A drop. The interrupting capacity drops sharply as voltage rises: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 500 V and 690 V. For a 480 V system (common in North America), you'd interpolate between the 440 V and 500 V figures; the 75.6 kA at 440 V gives headroom for most industrial services. Rated insulation voltage is 800 V, so the breaker is suitable for 690 V line-to-line systems with proper coordination.
Integrated auxiliaries and release
This variant comes factory-fitted with two auxiliary switches (HQ type) and an undervoltage release (UVR). The auxiliary switches give status feedback — open/closed position — to a PLC or status lamp without needing an add-on block. The undervoltage release trips the breaker if control voltage drops below a set threshold, which is standard for safety circuits where loss of control power must open the main disconnect. The base switch itself is the 3VA11805EF320AA0, so this is a pre-configured assembly, not a field-modified unit.
Physical fit and panel integration
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth. That 70 mm depth is the key constraint when mounting in shallow enclosures — standard 200 mm deep panels are fine, but retrofit into a 120 mm deep pull box might be tight. Width at 76.2 mm is exactly 3 inches, so it occupies three 25 mm DIN-rail modules. The breaker mounts via the standard DIN rail clip; no special adapter needed. Operating temperature range is -25 °C to 70 °C, storage from -40 °C to 80 °C.
Power loss and thermal management
Maximum power loss is 21.7 W at full rated current. That's the heat the breaker dumps into the panel. In a tightly packed enclosure with multiple breakers, that heat adds up — make sure your ventilation or cooling can handle it, especially if the breaker is running near its 70 °C operating limit.