What this MCCB is and what it does
The Siemens 3VA1163-4EF36-0HA0 is a SENTRON 3VA1 molded case circuit breaker (MCCB) designed for line protection in distribution panels and industrial switchgear. It carries a rated current of 63 A at 40 °C and holds that rating through 50 °C before a slight thermal derating curve begins — at 55 °C it's still 62 A, at 65 °C it's 60 A, and at 70 °C it's 58 A, so the full 63 A is usable across most normal panel ambient conditions. The breaking capacity is the headline number that decides fault-clearing fit: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That 121 kA at 240 V means it can safely interrupt a fault current up to that level without the arc re-striking or the case rupturing — critical for high-fault installations like transformer secondaries or large motor control centers where upstream SCCR demands headroom. It's a 3-pole unit with a TM240 thermal-magnetic overcurrent release and a shunt trip (STL) auxiliary release for remote tripping. The rated insulation voltage is 800 V, and maximum power loss is 17.3 W — useful to know for enclosure thermal calculations when packing multiple breakers in a confined panel.
Panel fit and integration
Dimensions are 130 mm height, 76.2 mm width, 70 mm depth — a standard 3-pole MCCB footprint that drops into most DIN-rail or panel-mount enclosures without surprises. The 76.2 mm width (3 inches) is the critical number for multi-pole ganging and busbar alignment.
What the ratings mean for your decision
The 63 A rating at 40 °C with minimal derating up to 50 °C means this breaker handles continuous loads like lighting panels, small distribution feeders, or motor branch circuits without needing oversizing for ambient temperature. The 121 kA interrupting rating at 240 V is the standout — it's high enough for most service-entrance or high-fault applications where a standard 25 kA or 65 kA MCCB would need upstream fusing or a current-limiting reactor. Compared to a lower-rated sibling like the 3VA1110-5EF32-0LA0 (which carries a lower current frame), this 3VA1163-4EF36-0HA0 is the higher-current, higher-breaking-capacity option in the 3VA1 family. The physical footprint is the same 3-pole width, so a panel designed for the smaller frame can accept this one without re-drilling or busbar rework — the mounting and connection pattern is consistent across the 3VA1 line.