Bus Wiring (Demystified!)
One of those concepts, as you can probably predict from the title of this post, was the topic of "bus wiring". For a long time I really didn't understand what this was or how it would benefit me. I recall reading some manufacturers DCC instructions and coming across explanations like "Connect the red wire to the main track bus" etc.... Utterly confusing to me.
For the first several years of my layout (fully DCC), I was, in fact, able to get by just fine without really having to worry about this. My wiring 'system' (if it can be called that) was to essentially use the Kato 3-way connectors in sort of a 'hub and spoke' arrangement to distribute power around my layout. Imagine the below with three more 3-way connectors branching off to power the track. This was my system and, for the most part, it worked.
As I started my expansion....and looked to add another 15 to 20 feet of running length to my main line, I started to question my 'lazy Unitrack' wiring scheme. Fortunately, a post on the JNS forum was able to explain, demystify, and encourage me to do the 'right thing' and move to a real 'wire bus' (after first reading other members postings on what exactly it was!).
As I discovered, "Bus Wiring" has nothing to do with buses, trams, trolleys, etc.... it really is (as far as I understand anyway) the simple fact of laying down a 'main' power supply around the layout and then 'tapping' into this 'main' power line for your track feeders. The below illustration is how I ultimately moved to a bus wired layout from the above 'lazy Unitrack' version:
For each of my four 'power districts' (the original 3 lines mentioned above, plus a new, separate section for all of the new yard tracks), I picked up 14 or 16 gauge stranded wire from the local automotive stores where I was also able to locate some handy 'suitcase connectors' which attach to the 'bus lines' and feature companion connectors that get crimped on to the 20-22 gauge 'feeder lines' that go to the track.
These electrically inclined people really do know what they are talking about! My issues, particularly on the "Blue Line", with poor responding locomotives have disappeared! The reason for this (covered in much more detail on the JNS Forum) is that on my longer routes, the actual DCC signal reaches the track at different times ---- granted this is in milliseconds---but it still (I believe) is enough of a delay for the decoder to get some sort of garbled signal from the DCC controller.
Note that this 'responsiveness' issue I had on the "Blue Line" was not a problem on my shorter routes (I elected to upgrade them to a 'wire bus' anyway) so I do think this problem probably only comes up when you reach a certain threshold in terms of route length. For small ovals, this will probably not be a problem, but as I experienced as I continued to add length, it was time for a better approach than the simple approach I was initially able to take.