63 A, 3-pole MCCB with undervoltage release — line protection duty
The Siemens SENTRON 3VA2063-6HN32-0BH0 is a 3-pole molded case circuit breaker rated for 63 A continuous current across the full ambient range from 40 °C to 70 °C — no derating required within that window. Breaking capacity reaches 242 kA at 240 V, stepping down to 187 kA at 415/440 V, 121 kA at 500 V, and 3 kA at 690 V. This is a line-protection design (per), not a motor-protection or ground-fault variant. It ships with an undervoltage release (UVR) integrated, plus 2 auxiliary switches and 1 trip alarm switch (HQ configuration). The UVR triggers a trip when supply voltage drops below a set threshold — common in safety circuits where loss of control power must open the main breaker. No communication function or ground-fault monitoring is fitted.
Panel fit and auxiliary wiring
Footprint is 105 mm wide × 181 mm tall × 86 mm deep. Mounts on a DIN rail or direct panel via the molded case. The 86 mm depth is within standard enclosure depth for 3-pole MCCBs in this class — verify gland-plate clearance if back-panel wiring is tight. The auxiliary switch block (2 aux + 1 trip alarm) occupies the right-side accessory slot; wiring exits the breaker face, not the base.
Power loss and thermal budget
Maximum power loss is 7.9 W at rated current. For a 63 A breaker in a sealed enclosure, this is modest — no forced cooling required in most panel layouts, but account for it in the overall thermal budget if the enclosure is densely packed.