Question on decoder color code

[ARTHILL]

Always something new. I am putting a Digitrax DZ 123 in my brass shay. My beginners question:

The colored wires do not come out of the decoder in the same order they do on the directions. Do I wire according to the wire color or according to the location they come out of the decoder? I am assuming the color code is what counts.

[mfm37]

David gave you the standard color code. All NMRA dceoder manufacturers will use that standard.

The wires order on the drawing is different order to make the drawing neater. Color code is gospel.

[ARTHILL]

Thanks. That was my guess, but your confirmation eases my mind a little. Now to see if I can get everything hooked up without melting the wrong things.

[jeffrey-wimberly]

Wire by color. Follow the color code used in the instructions and you won't go wrong.

[Enzo Fortuna]

Print this page:

http://www.loystoys.com/info/nmra-plugs-and-sockets.html

Is my "Holy page" !

Cheers

Enzo Fortuna

Modelling SP Coast Line in Italy

http://xoomer.alice.it/enzo_fortuna/

[jeffrey-wimberly]

I'll just make that link clickable so the others don't have to copy and paste it.

NMRA Plug and Socket

[cacole]

Decoder wire color codes are standard if the decoder complies with NMRA standards; however, I have ran into several brands of locomotives in HO and G scale that don't follow any color coding system at all in their factory wiring.  Some have been all black or all red wire, or some other color.  Bachmann G scale engines are very haphazard.  When I asked Bachmann if they had a wiring schematic for one of their G-scale products, their reply was that the factory in China had provided no schematics to them, and seemed to just be using whatever color wire thay had on hand.

[jeffrey-wimberly]

When I asked Bachmann if they had a wiring schematic for one of their G-scale products, their reply was that the factory in China had provided no schematics to them, and seemed to just be using whatever color wire thay had on hand.

In other words, an electronic shrug of the shoulders and dumb look.

[Randall_Roberts]

Orange=Motor (+)

Grey=Motor (-) I might have the motor leads reversed....

I haven't checked, but I believe that those are correct.  However, if you get them backwards... or if the guys using any color wire in China mess you up, it doesn't hurt anything. You can change the "forward" direction by changing a configuration variable (CV) in the decoder (at least every decoder I've worked with).  This is often preferable to resoldering the decoder leads.

Best! 

[Vail and Southwestern RR]

Orange=Motor (+)

Grey=Motor (-) I might have the motor leads reversed....

I haven't checked, but I believe that those are correct.  However, if you get them backwards... or if the guys using any color wire in China mess you up, it doesn't hurt anything. You can change the "forward" direction by changing a configuration variable (CV) in the decoder (at least every decoder I've worked with).  This is often preferable to resoldering the decoder leads.

Best! 

I disagree.  It's almost always better to swap the wires, and get things right from the beginning.  If you "correct" things with the CV, and then months from now the decoder gets reset, you'll spend some time thinking before you remember what you did.  And when you consist, you are going to be happier with everything starting from "standard", much less danger of things getting confused.

 

Assuming the loco ran "properly" on DC, the orange wire goes to the side of the motor that was hooked to the right rail, and the grey to the side that was hooked to the left.

 

[mfm37]

Assuming the loco ran "properly" on DC, the orange wire goes to the side of the motor that was hooked to the right rail, and the grey to the side that was hooked to the left.

 

 

That's good advice. Especially true if the engine is wired backwards and the lights are wired correctly.

No amount of CV adjustments will straighten normal direction and lights if one is wired backwards. 

 

Martin Myers 

[Randall_Roberts]

That's good advice. Especially true if the engine is wired backwards and the lights are wired correctly.

No amount of CV adjustments will straighten normal direction and lights if one is wired backwards. 

Decoders are built with lights dependent on direction of travel, not rail wiring. The forward light goes on when the locomotive is traveling in the forward direction, or when stopped having last been moving forward.  Its oreintation on the track makes no difference.

The DCC signal is technically an AC signal anyway, and the decoder has a rectifier that converts it to DC for the motor and lights, in addition to reading control information from its pulses.  The "forward direction" CV is most commonly used when creating a back-to-back consist, as this is the only way to get both locomotives going in the same direction when they are back to back.

As to the desire to wire it "properly"; that is always preferable.  I forget sometimes that most people on this board work in HO.  Resoldering the connections in HO is nearly always an easy thing to do. In N scale we frequently solder the orange and gray wires directly to the motor brush caps.  The safe way to do this is to remove the motor entirely from the frame, remove the brush caps (being careful not to lose the brushes and springs), solder the leads to the caps and then reassemble the whole thing.  Really good solderers may leave the motor in the frame if the brush caps are accessable, but they have to be very quick to keep from melting the plastic motor housing.

I personally don't trust my soldering skills, so I dismantle the frame and remove the brush caps.  If I happen to get them wrong (which I've only done once in over 40 installs) on a good day with a loco mechanism that assembles easily I'll disassemble again and swap the caps.  If it's a bad day with a tough dog, and it's my own loco... CV change for sure.

Best!