New installs

[KWilhelm]

Can new installs of railpro run on existing DC systems? Is there a certain voltage for the realpro needs to run correctly?

[Alan]

RailPro is designed to work on 14.8V. It will work on as low as 11v or as high as 16v.

The problem with DC power packs, as was explained on the Introduce Yourself thread, is their lack of filtering. Filtering is not needed or even desired for driving a conventional DC train motor. But it is an entirely different story when driving solid state electronics. They do not respond well to sloppy DC power. The output from a model train DC power pack is very sloppy. I'm not saying it won't work. I'm saying it won't work well and could potentially be damaging to the RP module.

[Dean]

Granted, DC power packs are not the best, but RailPro runs fine on DCC which is chopped up AC. Not only is the AC chopped up, but there are signals ( Packets? ) on the AC too.
I think the decoders have there're own filtering.

[Alan]

The AC signal on a DCC system is a square wave. The signal on a DC system is a rectified sine wave. Huge difference with respect to the effective voltage being delivered to the module. Here is a diagram from a previous post that shows the difference.