The Siemens 3VA1125-3GE42-0AA0 is a SENTRON molded case circuit breaker (MCCB) rated at 25 A continuous, with four poles and a TM220 thermal-magnetic trip unit. Breaking capacity hits 75.6 kA at 240 V, tapering to 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V — so it handles high-fault utility feeds downstream of a transformer, not just branch circuits. The TM220 release means thermal protection for overloads and magnetic for short-circuits; no electronic adjustments, no comms module.
Thermal derating and panel fit
Full 25 A rating holds up to 50 °C ambient; at 55 °C it derates to 24 A, and at 70 °C it's 23 A (–). That matters if this breaker lives in a crowded enclosure next to a drive or transformer — you lose 2 A by the time you hit 70 °C. Footprint is 101.6 mm wide by 130 mm tall by 70 mm deep (–), which is the standard SENTRON 3VA moulded-case form factor. Mounts on DIN rail or panel-mount plate; IP40 on the front keeps dust out of the mechanism.
Lifecycle and sourcing
Listed as current production — no end-of-life notice, no NRND flag. That means you can spec it into a new BOM without worrying about a last-time-buy window closing mid-project. Sourced to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.