DC loco runs in reverse when used with DCC System

[hawaiiho]

Bac-Man, et al

I have my conversion to DCC well under way. After a couple of glitches, things seem to be smoothing out.

One curious problem. When I run my DC locomotives, they run opposite to the direction indicator on the DC Controller.

The DC Controller is connected using the supplied interconnect cable to the DCC Controller, as recommended by the E-Z

Command instructions. I tried my grandson's month old Bachmann DC locomotive and it did the same thing.

Any ideas?

[richG]

Right now it sounds like the 8 pin NMRA plug is not in correctly. Unplug it it and switch it around. This is a fail safe you might say, design by the NMRA.

Rich

[hawaiiho]

Rich,

It sounds like the 8 pin plug-in that you are referring to is the one located in the locomotive.  My DC locomotives are all

pre-DCC and none of them have the NMRA plug. My grandson's locomotive is non-DCC ready, and I don't believe it has one either.

If this is incorrect and you are referring to another location, could you please explain where it is and how to get to it.

Thanks in advance.

[richG]

Sorry, I did not read your first message completely. I am not aware of how the EZ Command works for running DC only locos.
I have only used an older MRC 2000 for something like this.

Rich

[Yampa Bob]

Have you tried switching the wires to the track terminal section, as you would if DC power is applied directly to the tracks and the loco's direction does not "match" the direction switch for your chosen direction of running?

DCC locos will run forward/reverse as programmed and are not affected by orientation of loco on the tracks or track polarity.  But a DC loco is affected by orientation / track polarity.

If you have EZ Track, then just pull the track terminal plug and turn it over. If your terminal section has screws, reverse the wires.

Most DC controller direction switches are not labeled "forward" or "reverse". (at least none of mine are) Most assume that if the direction switch is mounted horizontally, and the switch is to the right, or if the switch is mounted vertically and the switch is in the up position, that indicates "forward".  Not necessarily, if the terminal plug is inserted correctly for, say counterclockwise running, and you turn the loco around on the tracks, the loco will then run backwards due to the "right rail rule", thus not matching the relative position of the direction switch.

In short, position of the direction switch on a DC controller is relative only to track wiring connection and direction of running. By "direction of running", I am referring to counterclockwise (right running), or clockwise (left running).

I hope my explanation does not confuse you.  Every modeler needs to understand the "right rail rule" for DC locomotives. The rule is, when the loco is moving "forward", then from the engineer's perspective, the right rail will be positive.

[hawaiiho]

I should have included that information. The DCC controlled turnouts also appear to be polarity sensitive. When I first set up the DCC, I put a DC locomotive on the tracks and set the power cable to the tracks so that the DC locomotive ran in the same direction as the direction indication on the DC controller.  The DCC controlled turnouts would not function properly for more than one cycle of the turn outs. So, I had to turn over the power cable to make the DCC turnouts operate. That caused the DC locomotives to reverse.

puzzled?

[Yampa Bob]

I am not familiar with the DCC turnouts, so I cannot attest to them being polarity sensitive. 

Someone with knowledge of these turnouts will have to take it from here.   

[bevernie]

 :DGREETINGS!! ???Bob, please excuse me, but I have somewhat of a "problem" with the "right-rail-rule": Some of my engines go one way, others go the other way, so how does one determine which is the "right" rail? (On some engines, would not the "right" rail be the opposite rail on other engines??)
                                                                                          THANX!!
                                                                                         Ernie
P.S.
     This is, of course, applying to DC TRAINS!!
                                                              THANX!!
                                                                  ECD

[richG]

Some years ago I learned, do not know where, that the right rail, engineers side, when it is plus DC compared to the fireman's side, left rail, the engine will go forward. I have always had a multimeter. The power pack should be in the FWD direction mode. Sometimes I had to switch the wires at the power pack to archive this.
If I ever had a loco do the opposite, I unsolder the motor wires and reversed them. This might have happened once.
Many locos have the motor mounted so the terminal on top is marked red or somehow designated as the terminal for plus voltage for forward. My interpretation.
All the recent steamers I have are like that. This has been my experience.

You will probably find something in the NMRA wiring standards that address this issue.

Rich

I found it finally. http://www.nmra.org/standards/DCC/

Store this in your Favorites folder. I just did.
I used Google and searched for "nmra wiring standards locomotive direction" in case you wonder how I found the link. No quotation marks.
The NMRA has a lot of standards the many modelres are not aware of.

Rich

[Yampa Bob]

Hawaiiho,
I did a search of the archives and found the following thread, in which "Moses" mentions setting the default turnout position. I am thinking your problem has to do with initial programming of the turnout. If you have the instructions, please review them again for a possible error in your programming sequence or method.

http://www.bachmanntrains.com/home-usa/board/index.php/topic,8008.0.html

To all:
The right rail rule is explained in Electrical Standards S-9 item II A as follows:

(quote)
II. CONTROL
A. Direction control by polarity reversing shall be provided. Positive potential applied to the right hand rail shall produce forward motion. (3)

(3) The term "right hand rail" as used herein means the rail to the right of the observer standing between the rails with their back to the front of the locomotive.
(end quote)

Suggest bookmarking/copying the following for reference:
http://www.nmra.org/standards/sandrp/s-9.html

[bevernie]

 ???GREETINGS!!  :oI'm confused!! Is this to say that the engines (note plurality) that operate in the opposite direction were not manufactured to NMRA STANDARDS?
   As I remember, there were two trains on THE ADAMS FAMILY that ran in opposite directions and it made for a good scene in several of their pro 8)grams!
   At any rate, I do enjoy the fact that some of my engines operate in opposite directions!!
                                                                                           THANX!!
                                                                                         Ernie

[Yampa Bob]

If two DC locomotives are wired to comply with the standards, then it is impossible to run them both in opposite directions, with both locos moving forward. Even if you have separate loops, both connected and powered by the same controller, one locomotive will run forward, the other will run backwards.

As Rich pointed out, a loco not wired in compliance with the standards requires switching the motor wires in order to run two or more in consist, regardless of orientation.

Repeating my previous comments, we all have a mindset that the position of the direction switch is relative to direction of motion.  True, with DC power, we attach the track wires so it does work that way, but if we then decide to run the opposite direction, the direction switch no longer matches (to our eye) the motion unless we switch track wires.

If I ran strictly DC, I would install another switch on the controller labeled R and L for right hand or left hand running, to make the direction switch always visually "match" my desired running direction.

[hawaiiho]

Yampa Bob,

I have checked the programing. They are programmed  according to Bachmann's instructions and the default setting is straight

as  provided by Bachmann.

It's not that the turnouts reverse, they quit working totally. If the polarity of the power feed to the track is reversed so that

the DC locomotives run in the  direction indicated on the DC controller, then the DCC turnouts quit operating.

If the polarity of the power feed to track is set so that the turnouts work, then the DC locomotives run in the direction

opposite to what is indicated on the DC controller.

[Yampa Bob]

Yes, I understand the problem. Unfortunately I don't have the answer.  The only solution I can think of is to just ignore the position of the direction switch, until someone else can shed some light on this.

I have no need for DCC turnouts, if they weren't expensive I would buy one simply to learn more about them. If I had the same problem, I would probably take the turnout apart and switch the power wires to the decoder. I'm thinking that would produce the same results you got when you switched wires at the track terminal.

Of course, being retired I no longer get paid to think, so the "thinker" is a bit rusty at times.    Believe me, I share your frustration, and will follow this thread closely as I am always eager to learn more about this fascinating hobby.

A question in my mind is, are the DCC turnouts not wired to be compatible with the add-on DC controller?

[bevernie]

If two DC locomotives are wired to comply with the standards, then it is impossible to run them both in opposite directions, with both locos moving forward. Even if you have separate loops, both connected and powered by the same controller, one locomotive will run forward, the other will run backwards.

As Rich pointed out, a loco not wired in compliance with the standards requires switching the motor wires in order to run two or more in consist, regardless of orientation.









:DThis is much like the definition of "NORMAL"!! What is "normal" to one may be completely "abnormal" to another, but, then again, that's what makes this hobby, as well as AMERICA so wonderful and unique! I can still be "WEIRD", and yet, "NORMAL"!!
     My trains that run in opposite directions have not been tampered with nor changed... they came from the manufacturer that way! Were they not manufactured according to "STANDARD"? I don't know. When was that STANDARD adapted? Some of them are POCHER and TYCO, so that would automatically say that they are a few days old; others are ATHEARN and AHM. I'm not sure if any of my BACHMANN'S run different ways, but they well may. Even if they are made in CHINA, this is still the good ol' U.S. of A.!!
                                                                                            THANX!!
                                                                                           Ernie







Repeating my previous comments, we all have a mindset that the position of the direction switch is relative to direction of motion.  True, with DC power, we attach the track wires so it does work that way, but if we then decide to run the opposite direction, the direction switch no longer matches (to our eye) the motion unless we switch track wires.

If I ran strictly DC, I would install another switch on the controller labeled R and L for right hand or left hand running, to make the direction switch always visually "match" my desired running direction.