The SIEMENS 3VA9673-0JJ43 is a SENTRON TA4.3 circular conductor terminal — a four-cable wire connector meant for the big stuff. It takes copper or aluminum stranded from 4/0 AWG up to 500 kcmil (that's 120–240 mm² stranded), and you torque it to 36.7 Nm. Three units per order. This is the accessory that lands on the line side of 3VA55, 3VA65, and 3VA66 molded-case breakers when you're feeding with parallel conductors or heavy-gauge aluminum.
What the torque number means on site
36.7 Nm is a serious torque — you're not doing this with a stubby screwdriver. That's a 1/2-inch drive torque wrench or a calibrated screwdriver with a hex bit. The stripped length is 0.9 to 1.75 inches (23–44 mm), so strip generous and make sure the conductor seats fully under the clamp. On a 500 kcmil aluminum, that torque prevents creep and thermal cycling loosening. If you're used to the little spring-cage terminals on control gear, this is a different league — it's a power connection that holds for years.
This mounts externally on the breaker — not a DIN-rail terminal block, not a busbar adapter. It bolts onto the line-side lugs of 3VA55, 3VA65, or 3VA66 frames. Four cables per terminal means you can parallel two conductors per phase or land a feeder and a tap in the same lug. No control wire tap on this version (confirms that), so it's strictly power distribution, no auxiliary sensing. If you're retrofitting an existing panel, check the breaker frame first — it's only for those three SENTRON series.