I tried to go back through forums here searching this topic but nothing directly popped up after reading many articles. Does this really matter anywhere in the layout other than the cost of the wire?
For the bus, use stranded. For feeders, I use solid. And always use fine (32-36 awg) stranded for any wired decoder installs.
It really depends on the specific application, what type of signal you are carrying, and the length of the run. Here are some general rules that I follow: Anywhere that has to flex, like module connecting cables, use stranded wire. When using stranded wire, tin the ends to avoid frayed ends. Track feeders - 24 gauge solid to just under the sub road bed, then 18 gauge stranded to source. Main DCC bus - 16 gauge stranded from Powerwerx. Control circuits - 22 gauge stranded or solid. Stall motor turnouts - 22 gauge solid or stranded. Solenoid (Peco) turnouts - 16 gauge solid or stranded with short run to capacitor discharge unit.
Other than solid wire holds its shape when bent, and stranded doesn't, there is no difference whatsoever, conductance-wise. Stranded is used mostly for situations where it is repeatedly being bent; like lift-bridge wiring and modular-layout connections.. Our AC power tools, iron, lamp power- cord, vacuum, TV power cord and car battery leads are all stranded because the move around allot . Our AC room outlets, house wiring, land line phone jacks, what have you, are solid. It's your choice what to employ.
For me, I use stranded 12 or 14 gauge for my main bus and Cat 5 solid for my feeders. Some say that stranded wire conducts better than solid but don't really know about that for our applications. Solid is much easier to solder to your rails and is the main I use it for feeders.
I use 22 gauge solid on all of my wiring except for connecting modules together where I use 18 gauge stranded wire. Also I make sure to connect the ends of the main buss so it creates a loop, effectively doubling the size of the wire. I'm able to run four N scale locomotives without any problems, think I could run five or six if I wanted. Joe
Somewhere, I cannot recall where, I read that the popular 'suitcase' connecters other wise known as insulation displacement connectors (IDC's) should only be used with solid wire. Apparently stranded wire can make a faulty connection. Also it is important to be sure that equal pressure is placed on both ends of the metal blade to insure a good bare wire connection.
