It carries an ETU350 electronic trip unit — that's the brain that handles the trip curve, adjustable for the load. The 187 kA interrupting rating at 240 V tells you this breaker can safely clear a fault up to that level without welding its contacts or cascading failure upstream; at 415 V it still holds 121 kA, and at 690 V it drops to 4.25 kA, which is typical for a 3-pole unit at that voltage. The 3-pole construction fits three-phase feeders — motor control centers, distribution panels, main incoming breakers.
Deployment context
The 105 mm width and 181 mm height fit the SENTRON 3VA frame footprint — it occupies the same cutout as other 3VA2 frame breakers.