63 A MCCB with 121 kA SCCR — selectivity headroom for the main feeder
The Siemens 3VA1163-4EF42-0AA0 is a 4-pole SENTRON molded case circuit breaker rated 63 A continuous (Iu) at 40 °C with a TM240 thermal-magnetic release. Its interrupting rating hits 121 kA at 240 V AC.
Panel fit and thermal management
The breaker measures 101.6 mm wide, 130 mm high, and 70 mm deep — a 4-pole frame that fits standard Siemens SENTRON mounting plates and busbar systems. Front IP40 protection means it's suited for enclosed distribution boards; no washdown rating, so keep it inside the cabinet. Power dissipation at full load is 17.3 W, which the panel cooling budget needs to absorb — not negligible in a densely packed enclosure.
TM240 release and insulation coordination
The TM240 thermal-magnetic release provides fixed thermal and magnetic trip settings — no interchangeable trip units, so the protection curve is locked at manufacture. Rated insulation voltage is 800 V, and the storage temperature range runs from -40 °C to 80 °C, wider than the operating range (-25 °C to 70 °C). No undervoltage release, no shunt trip, no communication function on this variant — it's a plain line-protection MCCB.