Line protection MCCB with TM240 release
The Siemens SENTRON 3VA1163-3EF46-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 63 A continuous current, designed for line protection in distribution panels. Its TM240 thermal-magnetic release provides fixed overload and short-circuit protection curves, set at the factory for 63 A — no field-adjustable trip unit, which simplifies specification but locks the rating. Breaking capacity reaches 75.6 kA at 240 V AC, dropping to 52.5 kA at 415 V and 11.9 kA at 690 V, so the available fault current at the installation point must be verified against these values. The 70 mm depth and 101.6 mm width fit standard Siemens SENTRON panel footprints, and the 4-pole configuration handles three-phase plus neutral switching in TN or TT systems.
Thermal derating and power dissipation
The 63 A rating holds from 40 °C through 50 °C ambient; above that it derates linearly to 58 A at 70 °C. In a sealed, uncooled enclosure the actual continuous current must be reduced accordingly — a panel hitting 60 °C ambient can only carry 61 A through this breaker. Maximum power loss is 17.3 W per pole, which sums to about 69 W total for the 4-pole unit; that heat must be considered in the enclosure thermal budget.
Integration notes
Mounts on a DIN rail or directly to a mounting plate via the SENTRON busbar system. The 4-pole width (101.6 mm) occupies four standard 25 mm module spaces. No undervoltage release, no shunt trip, and no communication function are built in — if remote tripping or status feedback is needed, an external accessory (undervoltage release coil or auxiliary switch) must be added. The TM240 release is non-interchangeable; for applications requiring adjustable long-time or short-time pickup, step up to the 3VA2 series with electronic trip units.