63 A MCCB with ETU350 — line protection for high-fault panels
The Siemens SENTRON 3VA2163-7HN32-0AA0 is a 3-pole molded case circuit breaker rated for 63 A continuous current across the full 40 °C to 70 °C ambient range, with no derating required up to 70 °C. Its ETU350 electronic trip unit provides adjustable overload and short-circuit protection, making it a fit for line protection in distribution panels where fault currents can reach 330 kA at 240 V AC or 242 kA at 415 V AC. The 800 V rated insulation voltage supports 690 V line-to-line systems, though the breaking capacity drops to 3.7 kA at 690 V — a figure that governs the available fault current at that voltage level.
At 500 V the rating is 187 kA; at 690 V it drops to 3.7 kA — a steep roll-off that matters when coordinating with downstream breakers on a 690 V bus. The ETU350 release supports adjustable I²t and instantaneous settings, giving the engineer room to achieve selective coordination with downstream 3VA1 or 3VA2 breakers.