Siemens SENTRON 3VA1163-5EE32-0AD0 — 63 A MCCB for Line Protection
The Siemens SENTRON 3VA1163-5EE32-0AD0 is a 3-pole molded case circuit breaker (MCCB) rated 63 A at 40 °C, designed for line protection in distribution panels. Its TM220 thermal-magnetic release provides fixed overload and short-circuit protection without adjustable trip settings — a straightforward fit for standard feeder circuits where selectivity coordination is already established. Breaking capacity reaches 187 kA at 240 V AC, 121 kA at 415 V, and 75.6 kA at 440 V, with a drop to 17 kA at 500 V and 690 V. That 187 kA figure at 240 V gives substantial headroom for high-fault utility feeds or transformer secondaries in industrial switchgear — the SCCR rating of the panel can be set at that level without a current-limiting fuse upstream. Rated insulation voltage is 800 V, covering 480/277 V and 600 V systems with margin. The 70 mm depth, 76.2 mm width, and 130 mm height fit standard Siemens SENTRON mounting bases; panel cutouts and bus-bar spacing match the 3VA platform. Maximum power loss at rated current is 17.3 W — a consideration for enclosure thermal rise in tightly packed assemblies.
Current Derating and Ambient Temperature
The breaker holds 63 A continuously from 40 °C through 50 °C. Above that, derating begins: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. In a sealed enclosure near other heat sources, the 55 °C derating point is the one to watch — a 1 A drop signals the thermal curve starting to move.