The Siemens 3VA4170-4ED34-3AA0 is a 3-pole molded case circuit breaker in the 3VA4 UL Frame 125 series, rated for line protection with a TM210 thermal-magnetic trip unit. Overload protection is fixed at 70 A (Ir = 70 A), and the short-circuit magnetic trip is set at 10× In (700 A). The breaking capacity class S delivers 25 kA at 480 V — enough for most commercial and light industrial distribution panels without cascading upstream breakers.
SCCR and selectivity
The 25 kA interrupting rating at 480 V places this breaker in the S-class of the 3VA4 family. For a 70 A fixed-trip breaker, that means it can clear a fault up to 25,000 A without welding contacts or venting gas into the enclosure. In a panel with a 65 kA available fault current, you'd need a current-limiting upstream breaker or fuse to coordinate — this breaker alone won't hold that. Pair it with a properly rated main, and the selectivity tables in the Siemens coordination manual apply.
Panel integration
Mounts on a standard DIN rail or panel-mount via the 3VA4 mounting accessories. The TM210 trip unit is non-interchangeable — Ir is fixed at 70 A, so if the load changes, the breaker itself must be replaced. Line and load lugs accept copper or aluminum conductors. The FTFM (fixed thermal, fixed magnetic) trip means no field adjustment of the magnetic pickup; it's locked at 10× In.