MCCB for motor protection — 100 A, 3-pole, with phase failure detection
The Siemens SENTRON 3VA2110-7MN32-0CC0 is a 3-pole molded case circuit breaker (MCCB) rated 100 A continuously at 40 °C ambient, with no derating required up to 70 °C — the full 100 A holds across the entire operating temperature range per the datasheet. Designed specifically for motor protection, it includes phase failure detection and an undervoltage release (UVR) as standard, making it a direct fit for motor branch circuits where loss-of-phase protection is required by code.
Interrupting capacity and selectivity headroom
At 240 V the interrupting capacity is 330 kA, dropping to 242 kA at 415 V and 440 V, then to 187 kA at 500 V. At 690 V the rating falls to 3.7 kA — this is a 600 V class frame, not a 690 V main breaker. For a 480 V panel fed from a 1000 kVA transformer (typically 25–50 kA available fault current), the 242 kA at 440 V gives substantial headroom for selectivity with downstream breakers. The short-time delay (adjustable 4 s to 17 s) allows coordination with feeder breakers on motor starting inrush.
Integration and mounting
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep — a standard SENTRON 3VA2 frame footprint that fits existing DIN-rail or panel-mount cutouts used across the 3VA series. The 86 mm depth leaves clearance for rear-access wiring in a 200 mm deep enclosure. Two auxiliary switches (HQ design) are built in; the undervoltage release is wired separately. No communication module is fitted — this is a standalone thermal-magnetic trip unit with no Modbus or PROFIBUS interface.