What this MCCB delivers for motor protection duty
The Siemens 3VA2163-5MN36-0BH0 is a SENTRON molded case circuit breaker (MCCB) purpose-built for motor protection — its design includes phase failure detection and a thermal-magnetic trip curve sized for motor starting inrush rather than resistive loads. Rated 63 A continuously from 40 °C through 70 °C without derating, it holds that rating across the full operating temperature band, which simplifies panel sizing in warm enclosures. The interrupting capacity at 415 V is 121 kA, giving ample fault-clearing headroom for most industrial distribution systems without needing a current-limiting upstream device. This is a 3-pole unit with an undervoltage release (UVR) factory-installed, plus two auxiliary switches and one trip alarm switch. The UVR ensures the breaker drops out on loss of control voltage — a standard requirement for safety circuits on conveyors, pumps, and compressors where automatic restart after a power dip is unacceptable. The auxiliary switch complement (2 form-C contacts) is enough to report breaker status back to a PLC or to drive a local pilot light without adding external relays.
Breaking capacity across voltage levels — selectivity planning
The interrupting ratings step down cleanly with voltage: 187 kA at 240 V, 121 kA at both 415 V and 440 V, 75.6 kA at 500 V, and 3.7 kA at 690 V. For a 415 V panel, the 121 kA figure means this breaker can be used downstream of a transformer or main breaker with a similar or higher SCCR without worrying about cascaded failure — it clears a bolted fault within its own rating. At 690 V the 3.7 kA limit is low; that voltage level typically appears in mining or marine systems, and this breaker would need upstream current limitation or a higher-rated device for those installations.
Panel fit and dimensions
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep — a compact 3-pole footprint that fits standard Siemens SENTRON mounting plates and DIN-rail adapters. The 86 mm depth is shallow enough for 200 mm deep enclosures, leaving room for wiring gutters and busbar connections behind the breaker. Panel builders should note the 6.5 W maximum power loss at full load when calculating enclosure ventilation.