I used an Atlas dc wiring book to wire the new layout designed for dcc. It showed the positive(red) wire on the left track when you face the track. Now I read the NCE book and see it tells me to put the red wire on the right (engineers) side of the track. Backwards of the way I wired the layout. Thought nothing of it when I tried a dc loco and it ran as it should. Now what?
DCC really has no positive or negative side, so the color code is immaterial. When you tell a DCC decoder to run the locomotive forward, it will go forward regardless of which wire is to which rail.
Which rail is which does not matter in DCC. Internal to the loco, the red wire going to the decoder goes to the pickups on the right side, and the orange and grey wires go to the motor such that when you command forward, that’s the way the train goes. In other words, you mistake isn’t.
Actually, it will make no difference which way the wires are hooked up for DCC. The wire color is a convention only, and does not affect the direction a DCC loco will go.
If you run a DC loco as Engine Zero, though, I think the polarity of the wires will make a difference.
In either case, DC or DCC, which colour wire you use is immaterial. You could even use two bare copper wires of the same gauge, or even different gauges, as long as they stay out of contact with each other and with anything else from a safety point of view, and are sufficiently sized for the job. (I would strongly advise against using bared wires, though.[B)])
What really matters is that you don’t cross wires anywhere by mistakenly connecting one of the left rail feeders to the right side of the bus, or vice versa. Using colours, any you choose, is just a handy and safe way to help you to keep feeders going between one rail and the appropriate bus wire.
I thank each of you for your help. Some of you must specialize in helping us new to the hobby as I see your comments and names often. Thank you for your time and answers. I have connected all black feeders to the black bus wire and all red feeders to the red bus wire. Hopefully I can now move on to another area of the layout. Thanks again to each of you.
For other possible questions/problems, here are a couple of great sources:
As the others have answered the question fully, I just have two comments.
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I have experienced a similar issue at the club and specifically with electrical and electronic issues. When following directions inexperienced people either seem to take the directions too literally, or not literally enough. What sort of vocabulary can we build that allows these things to be easier to explaine.
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This is another reason DCC seems hard. Novice people read all this stuff about busses and wire of massive gauges, feeders every x inches, blah de blah de blah. How can we communication that for the most part it is as easy as one wire to each rail?
The ‘red on the right’ wiring convention is for the decoder in the loco, based on the NMRA DC standard of right rail positive for forward motion. ANd red usually indicating a positive wire. Doesn’t really apply to DCC. Just be consistent in whatever you do - if you cross the track feeders somewhere you’ll hae a short.
What DOES matter in the decoder install is connecting the ORANGE decoder wire to the motor terminal that used to connect to the right hand rail, and the grey wire to the left motor terminal, assuming the loco ran correctly in DC. Otherwise, it will run backwards compared to the forward/reverse indication on your throttle. But if you do accidently wire one backwards, it can be fixed with the addition of 1 to the value in CV29, this changed the normal direction of travel for the loco (appears as NDOT in a lot of documentation) so you can fix a goof without taking everything apart and rewiring.
–Randy