What this 25 A MCCB does in the panel
The Siemens SENTRON 3VA2025-6HM42-0AA0 is a 4-pole molded case circuit breaker rated for 25 A continuous current, designed for line protection in distribution panels. Its 242 kA breaking capacity at 240 V AC handles high-fault scenarios without cascading upstream — critical for maintaining selectivity in a multi-breaker lineup. The 800 V rated insulation voltage gives headroom for 480 V and 600 V class systems.
Breaking capacity across voltage levels
Breaking capacity drops as voltage rises: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 3 kA at 690 V. The steep drop at 690 V means this breaker is not suited for 690 V line-side faults above 3 kA — verify your available fault current at that voltage before specifying.
Ground-fault and temperature derating
Ground-fault monitoring uses summation current formation on L + N conductors — no separate GF module needed for that function. The 25 A rating holds steady from 40 °C up to 70 °C ambient, so no derating in a warm enclosure. Power loss is 0.84 W maximum, negligible for thermal budgeting in a packed panel.