Motor protection MCCB with ETU350M — what the ratings mean for fit
The Siemens 3VA2216-7MN32-0HC0 is a SENTRON molded case circuit breaker configured specifically for motor protection, carrying a rated continuous current Iu of 160 A across a 3-pole frame. The ETU350M electronic trip unit provides adjustable overload and short-circuit protection curves matched to motor starting characteristics — meaning it tolerates the inrush without nuisance tripping while still clearing a locked-rotor fault. Breaking capacity runs from 330 kA at 240 V down to 52.5 kA at 690 V, so the same frame covers high-fault panels at lower voltages and standard industrial distribution at 400/480 V. Thermal derating is published from 40 °C through 70 °C: the breaker holds its full 160 A up to 50 °C, then steps down to 153.6 A at 55 °C, 150.4 A at 60 °C, 147.2 A at 65 °C, and 144 A at 70 °C. If the panel ambient runs above 50 °C, that derating curve is the one that governs the real load — not the nameplate 160 A. Phase failure detection is built in, which is the main reason to pick the motor-protection version over a standard feeder MCCB — it catches a lost phase before the motor single-phases to failure. The auxiliary contact package comes as 2 HQ auxiliary switches, and a shunt trip (STL) release is fitted for remote tripping.
Panel integration — dimensions and mounting
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep. It mounts on a DIN rail or can be screw-fixed to a backplate in the standard SENTRON 3VA footprint. The 86 mm depth is the projection from the mounting surface to the front of the breaker — relevant when sizing the gland plate clearance or door cutout. Maximum power loss is 75 W, so account for that heat in the enclosure thermal calculation, especially when grouping multiple breakers in a row.
Integrated components — basic switch and auxiliary trip
The breaker ships with a supplied basic switch 3VA2216-7MN32-0AA0 and an integrated auxiliary trip 3VA9688-0BL30. These are the internal switching elements that the ETU350M drives. If you are replacing a failed unit, verify that the replacement carries these same subcomponents — the order code encodes them, so ordering the full 3VA2216-7MN32-0HC0 ensures the correct match.