SENTRON 3VA2125-8HM36-0AA0 — 25 A MCCB with ground-fault monitoring
The Siemens SENTRON 3VA2125-8HM36-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for 25 A continuous current, with an adjustable thermal-magnetic trip unit covering 38 A to 300 A.
Breaking capacity and selectivity planning
At 240 V the 3VA2125-8HM36-0AA0 delivers 440 kA breaking capacity; at 415 V and 440 V it still holds 330 kA, and at 500 V it provides 220 kA. At 690 V the rating drops to 52.5 kA. These figures allow the breaker to serve as a main or branch device in high-fault-current installations, provided the system voltage and available fault current are coordinated. The 25 A continuous rating is derated uniformly across ambient temperatures from 40 °C to 70 °C — all listed at 25 A — so no thermal derating curve is needed within that range.
Physical integration and panel fit
The breaker measures 105 mm wide, 181 mm high, and 86 mm deep. It mounts on a DIN rail or directly to a backplate via the molded-case footprint.