The Siemens 3VA1225-6FF42-0AF0 is a 4-pole IEC frame 250 molded case circuit breaker rated In=250A with a 70kA interrupting capacity at 415V (breaking capacity class H). The TM240 thermal-magnetic trip unit gives adjustable overload protection from 175A to 250A and fixed short-circuit protection set at 5 to 10 times In. It includes a 50% rated neutral conductor protection, one changeover auxiliary switch, and one trip alarm switch — all factory-fitted.
Ratings and what they mean for fit
The 70kA Icu at 415V is the key number for panel builders: it means this breaker can safely interrupt fault currents up to 70,000 amps without welding its contacts or rupturing the arc chamber. That class H rating places it above standard 36kA or 50kA frames, so it suits high-fault installations like transformer secondaries or large motor control centers where the available fault current exceeds 50kA. The adjustable Ir (175–250A) lets you dial in the cable or busbar ampacity without swapping the breaker — useful when the connected load isn't exactly 250A.
Deployment context
This is a panel-mount breaker for fixed or plug-in installation in distribution boards and motor control centers. The 4-pole configuration with 50% neutral protection makes it suited for three-phase systems where the neutral conductor is sized smaller than the phase conductors — common in commercial and light industrial panelboards. The nut keeper kit simplifies busbar connection during assembly.