What the 55 kA Icu Rating Means for Your Panel
The Siemens 3VA2216-5MQ32-0DF0 is an IEC frame 250 molded-case circuit breaker with a breaking capacity class M rating of Icu=55 kA at 415 V AC across all three poles. That 55 kA is the ultimate short-circuit breaking capacity — the breaker can safely interrupt a fault up to that level once and still carry rated current afterward. For a motor protection circuit, this means it sits upstream of a motor starter and handles the worst-case bolted fault the supply can deliver without cascading to the next device. The ETU860M trip unit gives you LSIG protection — long-time (overload), short-time, instantaneous, and ground-fault — with an adjustable overload range of Ir=63 A to 160 A, so it covers motor FLA from about 50 A up to 160 A depending on the tap setting.
Deployment Context — Motor Control Center or Distribution Panel
This 3VA2 breaker mounts in a fixed or withdrawable chassis within an IEC motor control center or low-voltage switchgear assembly. The included nut keeper kit and the undervoltage release (UVR) are factory-fitted, so the panel builder only needs to torque the line and load connections. The auxiliary switch HQ and trip alarm switch HQ provide status feedback to a PLC or SCADA — one N/O + N/C for breaker position, one for trip indication. Ground-fault protection is adjustable Ig=0.2 to 1 x In with a time delay tg=0.05-0.8 s, which coordinates with downstream GFCI devices on feeder circuits.