MCCB with integrated undervoltage release — 100 A continuous, 187 kA interrupting at 240 V
The Siemens SENTRON 3VA1110-5EF32-0BA0 is a 3-pole molded case circuit breaker (MCCB) rated 100 A at 40 °C, with a TM240 thermal-magnetic trip unit designed for line protection. It carries an interrupting capacity of 187 kA at 240 V AC — that figure governs fault-clearing in low-voltage distribution; the breaker will safely interrupt a bolted fault up to that level without cascading upstream. The 800 V rated insulation voltage confirms it is built for 480Y/277 V and 600 V industrial panels with margin. This MCCB integrates an undervoltage release (UVR) as a factory-installed auxiliary release, so it drops the load when supply voltage falls below the dropout threshold — a standard requirement for motor feeder circuits where an automatic restart after a brownout would be a safety or process hazard. The UVR is part of the base order code, not an add-on module.
Thermal derating and ambient — what the 40 °C rating means for a hot panel
The breaker is rated 100 A at 40 °C ambient, and it holds that full rating through 50 °C (–). At 55 °C it derates to 98 A, at 60 °C to 96 A, at 65 °C to 94 A, and at 70 °C to 91 A (–). For a panel near a furnace line or a confined enclosure with limited airflow, that derating curve is the number that decides whether the breaker holds the load without nuisance tripping. The operating range is -25 °C to +70 °C (–), and storage range -40 °C to +80 °C (–).
Interrupting capacity across voltages — selectivity headroom
The 3VA1110-5EF32-0BA0 delivers 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at both 500 V and 690 V (–). The high 240 V figure suits it for large step-down transformer secondaries or heavy 277/480 V feeder applications where the available fault current is substantial. At 690 V the 17 kA rating still covers most industrial motor-circuit fault levels.