MCCB for line protection with high interrupting capacity
The Siemens SENTRON 3VA1063-3ED42-0KH0 is a 4-pole molded case circuit breaker rated for line protection, carrying 63 A continuously at ambient temperatures from 40 °C up to 50 °C before the first derate step kicks in at 55 °C. Its interrupting ratings climb to 75.6 kA at 240 V and 52.5 kA at 415 V, dropping to 32 kA at 440 V and 7.5 kA at both 500 V and 690 V — figures that govern selectivity coordination downstream in a distribution panel. The breaker includes a trip indicator and ships with a shunt trip release (STL) plus two auxiliary switches and one trip alarm switch HQ, so it can signal its state back to a PLC or annunciator without an add-on module.
Thermal derating and panel fit
Rated current holds at 63 A from 40 °C through 50 °C, then steps down by 1 A per 5 °C increment: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. If the panel ambient sits above 50 °C, size the upstream feeder for the derated value, not the nameplate. The enclosure measures 130 mm high, 101.6 mm wide, and 70 mm deep — a standard SENTRON 3VA footprint that drops into existing MCCB mounting bases without panel rework. Rated insulation voltage is 800 V, and maximum power loss at rated load is 17.3 W, which should be factored into the enclosure thermal budget if the breaker is enclosed with other heat sources.