This problem has plagued users for a long while now and is almost constantly an issue brought up on the LokSound groups.io forum. Guaranteed you'll see it brought up about every two or three days.
There are several reasons this could happen and the majority of them are easily remedied. There is a list of things that need to be checked and these are mentioned whenever the problem pops up.
- Make sure Drive Hold is not on
- Insure the Independent Brake is not on
- Insure the Automatic (Train) Brake is not on
- To learn how to implement the Train brake read this
- Make sure CV19 is set to 0 (not in advanced consist)
Now For The Insidious One
Recently, the author came across this problem in a couple of his locomotives and it always occurred when initially programming the decoder. It didn't matter if the engine was programmed from scratch or was a copy of a previously programmed engine with just the engine number changed. It happened in both instances and was always for a v5 decoder (that's what the author has) so, both 21 pin and micro decoders developed the problem.
Re-burning the unchanged original downloaded file from ESU (pure factory reset not a reset to previosly programmed values) would clear up the problem so what did the author change that caused this?
Today it was decided he was going to take the time and trace the cause. One sheet at a time utilizing the Drivers Cab to test running or not after changes and then go changed setting by changed setting on the particular sheet if the problem occurred.
This took some time. Brake Settings, Driving Characteristics, the various Function Sheets, all were fine. Motor Settings, WAIT!!! the engine refused to move!!! Now change by change until the author got to Motor Overload Protection. Long story short finally, checking the Enable motor current limiter would prevent the engine from moving! See figure 1.
Fig1 Motor current limiter
Think! Why? This was an older HO KATO AC4400CW purchased at a swap meet and it had the same changes made to a new one that was working. This makes perfect sense. The older motor needs more current than the new model and the protection wouldn't let it move because it was above the set limit.
Uncheck the Enable motor current limiter box, test, engine moves! Problem solved.
Don't forget this one after checking Drive Hold and all the different brakes don't fix the problem. Also remember that if after all of these checks are done and the engine still does not move, you probably have a blown drive circuit in the decoder and it requires a trip to Colorado for a fix. Remember that the ESU office has moved. It's no longer in Pennsylvania.
I hope this helps and I know it demonstrates what lengths you sometimes have to go through to isolate problems. Good luck!
If you have an idea for a blog post here, let me know. If I can comment on it, I will or I'll see if someone else can and post it
John - Great sleuthing !! This is something that I would never had thought of.
ReplyDeleteLet me get this straight. The engine wasn't moving because it was drawing more current than the current limiter would allow? And yet, when you told the decoder to forget the limit, the decoder did not burn out. I wonder how far below the rated current of the decoder the limiter is set for.
ReplyDeleteIt has to be pretty well below the burn-out threshold. I didn't bother to play around with the setting to see when it would allow movement. By the time I found this I was getting tired of messing with it. Future experiment. I'll publish my findings if and when.
ReplyDeleteOne thing I forgot to mention, by default the current delimiter is off. I turned it on out of an abundance of caution, silly me! The other locomotive was brand new so obviously it was drawing negligible current.
ReplyDelete