Hi, all
I’m designing some LED lighting based on TOP LED Functions Analysis and noticed that the manufacturer, who used to provide a 3-wire phase dimming driver as an option, no longer does. They said that the driver is no longer available from Lutron, and the suggestion was to use 2-wire phase dimming instead.

The fixture I was looking at was USAI B3RW, which used to offer a -D4 driver option. That looked like this, having a distinct “DL” or “dimmed hot” wire in addition to the “L” or “switched hot”. I was planning on mixing that with compatible RRD-F6AN-DV dimmers.

With the -D3 2-wire phase dimming driver, I’d be using RRD-6NA dimmers instead, with “dimmed hot” only. But I found the apparent discontinuance of the 3-wire phase driver somewhat surprising, because to me, it’s electrically cleaner to separate power (L) from control signal (DL).

Does anyone know what happened to the 3-wire phase dimming system? Many thanks.