What it is and what it does
The Siemens SENTRON 3VA2110-5JQ32-0AA0 is a 3-pole molded case circuit breaker rated for 100 A continuous current, built for line protection in distribution panels. It carries a full-scale value of 100 A and an initial trip setting of 20 A. This MCCB is designed for line protection, meaning its trip curve and thermal-magnetic response are tuned for cable and busbar protection rather than motor starting or generator backfeed. It includes a communication function, so it can report status or trip events back to a PLC or BMS — useful when you're trying to isolate a downstream fault without walking the whole panel.
Ratings and what they mean for fit
The 100 A continuous rating holds flat from 40 °C all the way to 70 °C ambient — no derating needed in a warm enclosure. That's unusual; most breakers start dropping current capacity above 40 °C. Here, the thermal curve is flat through the whole operating range (-25 °C to 70 °C), so you can size the breaker at 100 A and not worry about nuisance tripping on a hot summer day in a non-conditioned electrical room. Interrupting capacity varies sharply with system voltage: 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V. That 3.7 kA figure at 690 V is the one to watch — if your system runs at 690 V and the available fault current exceeds that, this breaker won't clear it safely. Stick to 480 V or lower for the high-fault applications. Dimensions are 86 mm deep, 105 mm wide, 181 mm tall.