What the lifecycle stage means for your BOM
The 5SN3-3-25: The lifecycle stage is 'current', meaning the part is in production. No last-time-buy window or phase-out notice is listed.
This trip device is designed to mount inside a compatible Siemens / ITE miniature circuit breaker chassis. It is not a DIN-rail component; it replaces the internal trip mechanism of a specific breaker frame. Verify the breaker model and frame size before ordering — the 5SN3-3-25 is not a universal fit. Weight of 0.35 kgs is consistent with a molded-case trip unit, not a full breaker.
Sourcing and documentation
The part is available through independent distribution channels.