100 A line protection MCCB with undervoltage release
The Siemens 3VA1110-3EF32-0CH0 is a SENTRON molded case circuit breaker (MCCB) rated for 100 A continuous at 40 °C, 3-pole, designed for line protection. It delivers 75.6 kA breaking capacity at 240 V, scaling to 52.5 kA at 415 V and 32 kA at 440 V, with a floor of 11.9 kA at 500 V and 690 V. That 75.6 kA figure at 240 V means it handles high-fault scenarios common in industrial distribution panels without cascading upstream — useful for main or feeder breakers in a selective coordination study. The breaker includes an undervoltage release (UVR) as the auxiliary release type, plus 2 auxiliary switches and 1 trip alarm switch (HQ design). The UVR automatically opens the breaker when supply voltage drops below a threshold, protecting downstream equipment from brownout damage. The trip indicator confirms a fault trip visually — no need to open the panel to check status.
Thermal derating and panel fit
Current rating holds at 100 A from 40 °C through 50 °C, then derates linearly: 98 A at 55 °C, 96 A at 60 °C, 94 A at 65 °C, 91 A at 70 °C. In a sealed enclosure at 55 °C ambient, you lose only 2 A — still well within a 100 A bus rating. The 70 mm depth and 76.2 mm width fit standard panel-mount cutouts for 3-pole MCCBs in the 100 A class; the 130 mm height is compact for a breaker with integrated UVR and auxiliary switches. Power loss is 27.5 W maximum at rated current — that heat must be accounted for in enclosure thermal calculations, especially when grouping multiple breakers. The insulation voltage rating of 800 V gives headroom for 690 V systems without derating the dielectric.