MCCB with ETU320 — selectivity and SCCR headroom
The Siemens 3VA2063-6HL32-0BA0 is a SENTRON molded case circuit breaker (MCCB) rated for line protection, built around the ETU320 electronic trip unit. At 63 A continuous current it holds full rating from 40 °C up to 50 °C, then derates to 53.55 A at 70 °C — a thermal curve that matters when the breaker sits in a crowded, warm panel. The interrupting capacity tells the real story: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 4 kA at 690 V. That 187 kA at 415 V gives substantial SCCR headroom for downstream coordination in high-fault industrial distribution.
What the ratings mean for panel fit
Three-pole, 105 mm wide, 181 mm tall, 86 mm deep — standard MCCB footprint for a 63 A frame. The ETU320 release is electronic (not thermal-magnetic), so trip curves are more precise and adjustable, but the breaker draws 7.9 W maximum power loss, which adds to the enclosure heat budget. No auxiliary contacts or shunt trip on this variant; the undervoltage release (UVR) is built in — verify the control voltage matches your coil supply before wiring. Mechanical endurance is 20 000 operations, adequate for a distribution feeder but not for frequent switching duty.