Hi, Am building a 9x5 layout of 2 ovals - one inside the other, connected by parallel DCC friendly crossovers on the straights. Inside the ovals will be switching yard. My question - best way to power the inner oval? Do I simply run a set of wires from power source to the outer oval and then another set to the inner oval? Regards,
For DCC, you will want to run more than one set of feeders per oval. Rule of thumb is drop feeders every 3 to 6 feet; if sectional track and "permanent", drop feeders to each section when feasible. What you don't want is a long run of track with no feeders, as you will see voltage drop of the DCC signal. You will want some feeders on either sides of your turnouts, as well As long as you don't do any reversing loops, keep the polarity the same between the ovals (i.e. outer=outer; inner=inner)
You should wire them separately, although the same power pack can power each oval. The only thing you would need to do if in DC is to also have a toggle switch in series between the main wires supplying the feeder(s) to each oval so that you can actually turn off the power to one, or both, if you don't want engines or lighted passenger cars taking power. For example, you want to use a train on the inner oval only. You would flick the toggle that shuts down power to the outer oval if you don't want the engine(s) on that oval to move at the same time...which they will unless you break down the ovals into districts or blocks that are also controlled by toggles. In DCC, none of this matters. In both cases, you would want to watch power-routing turnouts on either end of a crossover between the two ovals...you would end up with a short.
First of all, welcome to the forum. You really only need one set of buss wires for the two ovals with track feeders placed every three feet or so. But running set of buss wires for each oval would be better. Later on you could add an individual circuit breaker for each buss so incase you get a derailment with a short circuit it will only shut down the track with the problem and not the entire layout. These are called power districts. You can purchase individual circuit breakers, or multiple breakers like digitrax's PM 42. Segments of the PM 42 can also be used as an auto reversing unit. This also helps with troubleshooting
