What this MCCB is and what it does
The Siemens SENTRON 3VA2163-6HL36-0JA0 is a 3-pole molded case circuit breaker rated for 63 A continuous current (Iu) in a line protection configuration. It carries an ETU320 electronic overcurrent release with a shunt trip (STL) auxiliary release built in — no separate undervoltage release, no ground-fault monitoring, no communication module. The breaker is dimensioned at 105 mm wide, 181 mm tall, and 86 mm deep, fitting standard SENTRON panel cutouts and busbar systems.
Breaking capacity — what the numbers mean for selectivity
This MCCB delivers 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 5 kA at 690 V. Those are the short-circuit breaking capacities (Icu) at each voltage level — the current the breaker can safely interrupt once. For a 63 A frame, 242 kA at 240 V is exceptionally high, which means you can place this breaker close to a large transformer or generator bus without worrying about the fault current exceeding its rating. At 690 V the capacity drops to 5 kA, so if you're on a 690 V line, verify that the prospective fault current stays under that threshold or coordinate with an upstream current-limiting device.
Thermal derating and operating range
The breaker holds full 63 A rating from 40 °C up to 50 °C ambient. At 55 °C it derates to 60.6 A, at 60 °C to 58.3 A, at 65 °C to 55.9 A, and at 70 °C to 53.6 A. Operating ambient range is -25 °C to 70 °C, storage range -40 °C to 80 °C. Maximum power loss is 4 W. If your panel ambient runs above 50 °C, factor the derating into your load schedule — the breaker won't trip early, but you lose headroom.