The Siemens 3VA2125-8HM42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated for 25 A continuous current, built for line protection in 4-pole configurations. Its 440 kA interrupting capacity at 240 VAC means it can clear a massive fault without upstream coordination worries — out here in the grease, that's the difference between a local trip and a whole panel blackout. The 800 V rated insulation voltage covers 480 V and 600 V class systems with headroom to spare.
Breaking capacity at system voltage
This MCCB delivers 440 kA at 240 VAC, 330 kA at 415 VAC and 440 VAC, 220 kA at 500 VAC, and 52.5 kA at 690 VAC. For a 25 A frame, those numbers are high — it's sized for high-fault locations like transformer secondaries or large motor control centers where available fault current runs hot.
Lifecycle and sourcing
The 3VA2125-8HM42-0AA0 carries a current-production lifecycle status. It's sourced and quoted to order against an RFQ through independent distribution; availability and current pricing are confirmed at quote time.
Ground-fault and temperature performance
The ground-fault monitoring uses summation current formation on L + N conductors — it watches the vector sum, not just a single path. The breaker holds its full 25 A rating across the entire -25 °C to 70 °C operating range with no derating needed, which simplifies panel design in hot environments like pump houses or compressor rooms. Storage range spans -40 °C to 80 °C for spares sitting on the shelf.
Physical fit and panel integration
The breaker measures 140 mm wide by 181 mm tall by 86 mm deep. That 4-pole width is standard for a 25 A frame MCCB — it occupies one full DIN-rail mounting space on a panel backplate. Power loss is only 0.5 W maximum, so heat buildup inside a sealed enclosure is negligible.