I would like to know what gage wire is most commonly preferred for supplying power to the tracks in HO Gage. Also, is stranded wire preferred over solid wire? Thank you.
Chuck
Woodland, CA
First off, Welcome to the forum, Chuck! [#welcome]
Assuming that you are talking about DC operation, 22 guage should be fine under most circumstances. There is very little difference in conductivity of stranded vs solid wire so either will work fine. The choice is one of personal preference. There are many threads devoted to electrical items here. If you are new to the hobby spend some time checking out threads both here and on the layouts and layout building pages for more information. If you let us know more information about what you plan to create and run, we may be able to give you more information and help you out.
Have fun with your trains!
For one HO locomotive, using a DC power supply, I agree that 22 gauge wire, stranded or solid, should suffice for as much as 15’ of track. Much longer, and if you add another loco, particularly in On30, you are now drawing some power, and I would upgrade to 18-20 gauge, particularly to allow for continued “development” (growth).
For DCC operations, it is common practise to use a short, but heavier gauge bus that runs parallel to the major trackage, that needs not loop or reach to the far end of a loop of track. It has 18-22 gauge feeders from the bus to the rails every few feet…your choice between every 3’ section if using flextrack, to every 8 feet to keep voltage drops between feeders to a minimum. If you enjoy that sort of thing, wire every joiner to provide continuity to every inch of rail. Otherwise, most of us live with about 6’ between feeders, give or take.
Solid core is usually used as feeder wires because they don’t need to be flexible (the perk of stranded) and it is easier to keep a single larger wire snug against the outside of the rail while you are soldering it.
For bus wires (the ones that run parallel to the rails and to the feeders when not using parallel wires) go with larger gauge stranded as they will take more abuse and won’t necessarily be replaced every time the track gets altered.
First - stranded versus solid wire:
If the connection is immovable, like a rail drop to a terminal strip, solid wire is preferred. Just put it in with a right-angle bend or two, not guitar-string tight. It has the advantage that there are no little loose strands to form hard-to-find shorts.
If the connection moves, like the connections to the moving poles of RIX switch machines or to a swing up section of track, always use stranded wire. If solid wire is flexed it will eventually break.
Second - wire size:
It depends on the length of the wire, the amount of current to be carried and the amount of voltage drop that can be permitted. DCC is not very tolerant of reduced voltage, so #12 busses and #18 drops (rail to bus connections, usually less than 24 inches long) are recommended for any but the smallest layouts. OTOH, for DC operations, I have had satisfactory results with #22 drops (up to about 60 inches) and #16 bus wires.
With switch machines, too, the size you need is driven by the amperage which will be drawn. Tortoise machines can get along with small (high AWG number) wire, since their current draw is microscopic. OTOH, my huge double-coil Katsumi rock smashers pull three times as much power as any of my old open-frame-motored locos, so the switch machines need bigger wire than the rails!
For more than you ever wanted to know about wire resistance and maximum current for the various sizes, the chart at this link tells it all:
http://www.powerstream.com/Wire_Size.htm
Chuck (modeling Central Japan in September, 1964)