What it is and what the ratings mean
The Siemens 3VA4145-5ED24-3AA0 is a 2-pole molded case circuit breaker from the 3VA4 series, built on a UL Frame 125 platform. Its headline rating is 45 A fixed thermal-magnetic protection (TM210 curve) with a 35 kA interrupting capacity at 480 V AC — that M-class rating means it safely clears faults up to 35,000 A without welding or rupturing, which is the spec that decides whether it coordinates with upstream gear in a 480 V panel. The overload protection (Ir) is permanently set at 45 A, and the short-circuit pickup (Ii) is fixed at 10 × In, or 450 A. No field-adjustable dials — what you order is what protects the circuit, so verify the 45 A fixed trip matches your branch load before specifying. This breaker is class C per Siemens' own classification: manufactured or produced to order, not a stocked shelf item. That means it ships from the factory against your order, not from a distributor bin — plan lead time accordingly.
Compliance and documentation
RoHS compliant since 13 May 2019. REACH Article 33 disclosure applies: lead (CAS 7439-92-1) is present above 0.1% w/w in the product. Export control is AL N / ECCN EAR99 — no special license required for most destinations. Packaged singly, dimensions 472 × 396 × 213 mm. The product group code is 5385; the group code is P360 — these are Siemens internal classification fields that sometimes appear on BOM cross-references or ERP lookups.