I'm completely new to this DCC stuff. I don't even have a system picked out yet. I have a couple questions.
My first question... can anyone recommend a good user-friendly small system? I have 5 locos now and may only add 1-3 over the life of this DCC system. I see MRC has some nice features on their lower model but again I am still learning here.
Also, my layout is currently wired for DC with 22 ga track feeds. I hear this wire size is safe in short distances for DCC, and so I will probably add an 18 ga main feed. So my second question... what about all those plastic rail joiners on my layout now? Will they interfere or even melt?
Thanks!
I would stick with either a Digitrax Zephyr or NCE PowerCab, both can grow with you. And both have better support than MRC because neither NCE or Digitrax is afraid to give you the details of how things work. Digitrax especially has a large array of third party products that work with it for signals and turnout controls, so you aren't stuck using just what they sell.
The number of DCC locos you have really has nothing to do with how big a system you need. It's how many you plan to actuall have moving on the layout at any given time. You could own 1000 locos but only ever run 1 at a time.
Yes, connect your small feeders to a heavier wire to conenct them back to whatever DCC system you end up with. How big is your layout? #18 might be a bit small.
And no, plastic joiners won't melt. Do you have feeders and insulated joiners in both rails now, or just one with one rail being common? If the latter, you'll want to add more feeders on the common rail side, otherwise you'll be relying on the rails and rail joiners for power transfer for that rail while the other side has multiple feeders.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for the system suggestions... I'll look into those.
My layout is 10' x 16' HO Scale. My current DC system uses insulated rail joiners on both rails to maintain completely isolated blocks. So, it sounds like I'll have these feeders at numerous points on my layout... is DCC ok with that? The more the merrier?
That's the way it should be. I always disliked common rail DC wiring and insualted and had feeders to both rails before I went DCC. The more feeders the better - rail joiners are notoriously unreliable ways to transmit electrical power from one piece of track to another.
For a layotu that size, larger bus wire like #16 or #14 is probably better, depending on how things are oriented and how long said wires would be. If the layout is around the walls of a 10x16 room (about the size of the one I'm building now), that could be quiote a long wire run. For exampl, if the DCC system is located int he center of one of the 16' side, and you run equal lengths of wire in each direction, you have a run length of 52': 8 feet to the left, 8 feet to the right. 10 feet down the left side, 10' down the right side. Another 8 in from the left, and 8 in from the right: 8+8+10+10+8+8 = 52. Times 2 because you need a complete circuit (2 wires). 104 total feet of wire, 42' total in each direction. Assuming you'll only have a max of two fairly recent HO locos at the furthest point as the worst case, to prevent noticeable voltage drop at that 52' distance, you'll want to use #16 wire. With a load of 2 amps 52' away from the power source, that would result in a bit under a half volt drop, which should be fine.
The real key is that the DCC's circuit breaker trips. Even many of the 'starter' DCC systems put out more current than basic DC power packs. If the wire is insufficient, a loco can derail and run say 2 amps through internal wires or the trucks, generating enough heat to melt things yet not exceeding the 2.5 amp capacity of the DCC system - so it never cuts power and you loco or the decoder ends up melting. The way to check this is really simple (and cheap). Just take a quarter (or equivalent if not in the US) and lay it across the rails. WITHOUT pushing down on it, the DCC system should see this as a short and trip the breaker. If it doesn't, check your wiring to make sure the bus is thick enough to support the current without excessive drop and that there are enough feeders.