What this 3VA4 breaker is and what the ratings mean
The Siemens 3VA4150-6ED14-3AA0 is a 1-pole molded-case circuit breaker in the 3VA4 UL Frame 125 family, sized for branch-circuit protection on 277 V line-to-neutral systems. The headline number is the 65 kA interrupting capacity at 277 V — that's the H (high) breaking capacity class, meaning it can safely clear a fault up to 65,000 A without welding or rupturing. For a 277 V lighting panel or a single-phase subfeed, that's enough to handle most utility-side fault currents without cascading upstream. The thermal-magnetic trip is TM210 with a fixed 50 A continuous rating (Ir=50 A, permanently set — no adjustment dial) and a short-circuit pickup Ii=10 x In, so the magnetic trip fires at 500 A. The FTFM designation indicates the trip unit is factory-fixed and non-interchangeable. This is a line-protection breaker, not a motor-protection device; it follows the UL 489 standard for branch-circuit protection, so it's the right call for a panel feeding resistive or general-purpose loads, not a motor starter with inrush to manage.
Lifecycle and sourcing reality
RoHS compliance is confirmed from 2019-05-13 onward. Note the REACH Article 33 disclosure: the part contains lead (CAS 7439-92-1) above 0.1% w/w in one or more homogeneous materials. This is typical for electrical contacts and solder joints in industrial breakers; it doesn't block use in most industrial panels, but your quality-doc team should log it for any customer-facing REACH declarations.
Mounting and integration notes
The 3VA4 Frame 125 is a panel-mount breaker with a standard bolt-on footprint. It occupies a 1-pole width on the bus — roughly 25 mm per pole for this frame. The packaging dimensions (472 x 396 x 213 mm) give you an idea of the shipping box; the breaker itself is smaller, but the box includes the molded packaging for the made-to-order unit. Terminal lugs accept copper or aluminum conductors up to the frame's rating; torque specs are on the nameplate.