What this MCCB carries and where it fits
The Siemens 3VA1225-4EF42-0AB0 is a SENTRON molded case circuit breaker (MCCB) rated for 250 A continuous current with a TM240 thermal-magnetic overcurrent release. Its 4-pole construction and line-protection profile make it the primary feeder breaker in a distribution panel or a main disconnect for a motor control center. The interrupting ratings climb to 121 kA at 240 V and 75.6 kA at 415 V — figures that govern its placement in high-fault-current locations like transformer secondaries or large busway taps. At 250 A, the breaker holds its full rating from 40 °C up to 50 °C ambient; above that it derates in steps to 223 A at 70 °C. That derating curve matters when the breaker lives in a non-ventilated enclosure or near other heat sources — the actual trip point shifts with the panel temperature, so the continuous load should be sized against the ambient-adjusted value, not the nameplate 250 A. The 3VA1225-4EF42-0AB0 includes two auxiliary switches (HP type) for remote status feedback. No undervoltage release, no shunt trip, no ground-fault module, and no communication function are fitted on this variant. If the application needs a remote trip or a ground-fault alarm, this order code is not the one — the auxiliary release slot is empty and the breaker lacks the internal wiring for those options.
Mounting and panel integration
The breaker measures 140 mm wide, 158 mm high, and 70 mm deep — a standard footprint for a 250 A SENTRON frame. It mounts via screw-clamp terminals to a backplate or DIN-rail adapter (not included). Front face carries an IP40 protection rating, suitable for enclosed panel installation where no water jets or dust ingress are expected. The 15000-cycle latching endurance covers the mechanical life; electrical endurance depends on the load type and switching frequency.
Compliance and documentation
The 3VA1225-4EF42-0AB0 is designed to meet IEC 60947-2 and UL 489 standards for molded case circuit breakers. The manufacturer provides RoHS and REACH declarations, along with the device manual covering DC-network application notes (referenced in the spec as a separate document). The reference code per DIN EN 81346-2 is Q, confirming its role as a switching device in the functional classification.