The Siemens 3VA4140-4ED24-3AA0 is a 2-pole molded case circuit breaker from the 3VA4 series, rated 40 A continuous with a 25 kA interrupting capacity at 480 V. It uses a TM210 thermal-magnetic trip unit with fixed overload protection set at Ir=40 A and short-circuit pickup at Ii=10 x In (400 A). The UL Frame 125 designation means the breaker body is sized for 125 A frame hardware — the 40 A trip is installed at the factory, not field-interchangeable without swapping the entire unit. This is a line-protection breaker (FTFM — fixed thermal, fixed magnetic), so the Ir and Ii values are permanently set. If your load profile requires adjustable overloads or a different magnetic pickup, you need a different trip variant. The 25 kA SCCR at 480 V covers most commercial and light industrial panelboards; for higher fault currents (65 kA or 100 kA) you step up to the S or H breaking capacity class in the same 3VA4 family.
Integration notes
The 2-pole form factor occupies two module widths. Line and load lugs accept copper or aluminum conductors; torque specs are on the nameplate. The TM210 trip provides inverse-time thermal protection for overloads and instantaneous magnetic protection for shorts — coordination with downstream branch breakers requires checking the time-current curve (available in the Siemens 3VA4 selectivity manual).