I have two modules, total length 12' with 16 ga wire and the Power Cab in the middle. It runs fine.
Having moved, I have the option of extending both ends into dogbones, 12-14' a side for a max length of 14+14+12= 40'
Should I take out the old bus and replace it with 14 ga or can I tack 14 ga onto the ends of the bus I have?
Henry
COB Potomac & Northern
Shenandoah Valley
As long as it's copper wire, adding it with electrical twists works in all the junction boxes in every home built in America or Canada. (I'm not sure about New Zealand where the Bear lives though) The rule of thumb is never downgrade wire on the end of a circuit to code.
Being that you're running low voltage I know you'll be just fine Henry
14 gauge, 16 gauge or the mix of both wire has more continuity than you'll ever need on a model railroad. They are both Overkill and you will be just fine.
Unless someone here surprises me and says DCC is very finicky and a mix of wire will conflict?
TF
It all depends on how many trains you plan to run. If you aren't going ot upgrade the PowerCab, then it can't be very many. In which case adding on witht he same size wire won't be a problem. There won't be enough current draw to cause a large drop. See, TF, since with DCC you have a lot of trains moving at the end of the bus run - you DO need heavier wire, #16 is most definitely not overkill. If you are going to run 4 amps worth of trains (which can be just ONE O scale loco with DC power as well - so there is a need for heavier wire with larger scales, too) at the end of 40 feet of wire, there will be a more than 1.25 volt drop - which is enough to be noticeable. Up that to #12 wire - and you get about .5 volt drop, which is about as much as you want. However, #16 wire, one HO train at 1 amp, and it only drops .032V. Not an issue - so going over #16 when there can be no more than a 1 amp load, would be overkill.
Now - I have a question on the length. Do you have TWO modules that are each 12ft long, or are the two 6 foot modules for a total of 12 ft ont he existing layout? If the latter, you have overestimated the length of the bus to each side by 6 feet, if you keep the PowerCab in the middle of the 12 foot section.
Also, if you are going to put dogbones on the ends - do you intend to parallel tracks through the straight part, or just one? It's technically only a dogbone if there are two mains parallel, with loops at the ends conencting them. If they are just loops that loop back on themselves for a single track, then it's a loop to loop layout.
In either case - you'll want to isolate the end loops and power them with autoreversers. And the maximum bus length will be from the center of the existing layout out (so either 6 or 12 feet) plus the diameter of the loops (put the AR in the middle, and run feeders out to the loop tracks, like spokes of a wheel), plus maybe a little extra if you have some stright on these new modules before the loops.
Let's say you add a 12 foot module on each end of the existing layout, and put in 30" radius loops. The loop take sup some 90" (loop radius, plus half circle to get back parallel to the main) so we'll say 8 feet to allow room at the edge, which means another 4 feet of straight to connect to the existing. That means you would have a total bus maximum length of something like 6(or 12) + 4 + 8, or 18 (or 24) feet from the middle. So far shorter than you were calculating (no need to run it up one side and then loop around the circle of track).
So #16 will be fine for the entire thing, unless you plan to upgrade the PowerCab and have more people running more trains at the same time.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
My layout grew in sections. If I were starting over, I would have gone with heavier wire, but I started with 18 gauge and that has been fine so far. Mostly, I run 1 or 2 trains and maybe a switcher between them. For me and my layout, that's the capacity of my brain. One of the trains might have two powered engines. I have a 5 amp Lenz system.
I have two autoreversers and 4 PSX breakers. The command station feeds all of those directly, and all power to tracks comes through he breakers and autoreversers. I have the base station at roughly the center of the layout.
It takes an iron man to play with a toy iron horse.
Thanks everyone, it is HO, Power cab and two 6 foot modules. I have no plans for having multiple operators or a booster.
I haven't put pencil to paper yet but I was thinking a loop on one side and a dog bone reversing loop on the other. I need to start another thread on how to build the benchwork for a 30" radius and still have access to the back part of the layout.
BigDaddy Thanks everyone, it is HO, Power cab and two 6 foot modules. I have no plans for having multiple operators or a booster. I haven't put pencil to paper yet but I was thinking a loop on one side and a dog bone reversing loop on the other. I need to start another thread on how to build the benchwork for a 30" radius and still have access to the back part of the layout.
Well a new thread would be ok, but I will just suggest access hatches, or turn the wings out into the room if you have the space, and make it so you can get to three sides of the loop.
My new layout will have benchwork 3-4 feet deep almost everywhere, even deeper in places, and two peninsulas 9' - 10' wide to allow for 38" plus curves. Access - hatches in places, rear aisles in places, and benchwork strong enough to climb on/lean on everywhere.
I tried the "book shelf", 2' deep thing, and I tried the double deck thing, did not like either one. So back to more "old school" design for me.
But it is a walk around plan with a linear track plan and all switching operations close to the operator.
I just need more "depth of scenery" than the 100' along the right of way and gentle curves are a must.......
Sheldon