The 3VA9771-0JJ53: For stranded copper, this connector accepts 300 kcmil minimum up to 600 kcmil maximum. For stranded aluminum, it handles 300 kcmil minimum up to 400 kcmil maximum. The stripped length needed is 1.2 inches — mark your jacket before you cut.
This terminal is designed specifically for 3-pole 3VA58 and 3VA68 frames. It's not a universal lug — it mates to the breaker's line or load side bus bar interface. The TA7.3 designation means it's the circular-pattern version, not a split-bolt or mechanical set-screw style. No control wire tap on this one, so it's strictly for power feed-through.
Sourcing reality — active, quoted to order
The lifecycle status is active — Siemens still lists this as a current product. No last-time-buy notice, no phase-out date on the horizon. That means it's a safe BOM line item for new builds or panel retrofits.