I have read about this happening to other folks but this is the first time for me. Other night one of my Engines went nuts and I had a runaway train.
Background, it happened to my HO Blue Line RSD 15 using a Digitrax DZ 163 decoder. I will add it been pulling freight for the last week and was working like a champ.
First sign of trouble was night before last. I added a few more coal cars to the drag. Engine would run, then stop but the sound decoder would still react to the throttle. Let it sit for a few minutes and it would move then stop again. Stared up next day and did the same thing. Found one of the Kadee couplers had dropped some and the coupler wire might have been hitting the rails. Pulled the 4 cars I added and it ran fine for another 2 hours or so.
Last night I was pulling some slow drag's around 18% power using by SEB. Ran great for a hour or so. Then all of a sudden it took off like a bullet. Would not react to the throttle so I killed the power at my DB 150. Turned the power back on and the Sound Decoder would react but engine would not move.
Monday I am going to install the decoder in a none sound engine and read, then reset the decoder to factory default using Decoder Pro. From my understanding what mainly causes runaways is having the DC side enabled. Is there any other CV's I should look at?
Thank You For Your Time!
Ken
I hate Rust
The runaway problem is almost certainly related to CV29 not being set to a value of "34", Ken, which is the value if you don't want the decoder to react/be sensitive to DC current as an input. Sometimes the decoder 'sees' DC when it isn't there, and goes to maximum voltage output to the motor with the predictable results. Setting the CV to "38" is for a decoder that has both a long address and where you want it to respond to either type of voltage if it happens to be applied to the rails.
So, we set CV29 conventionally to either value when we impart a 'long' address, or an 'extended' address such as a cab number higher than 126. Assuming you do have an extended address for that Digitrax decoder, you would necessarily have also set it to either 34 or 38, but I am pretty darned certain yours is set on the dual-sensitivity value of 38 in CV 29. Change it now, carefully to not get address changes in other decoders on the rails...ops mode. You should never have that problem again.
Crandell
As I walk along,I wonder what went wrong,With my train, the coal drag was so long.And as I still walk on,I think of MUs I've doneTogether, a-while their bells were rung...
I'm a-walkin' with my train,Round the loop, and then round again,Wishin' it would stay by me,To end this mysteryAnd I wonder--I wah-wah-wah-wah-wonder,Why,Why, why, why, why, why it ran away,Yes, and I wonder,A-what CV,Will end this runaway,Run, run, run, run, runaway. with apologies to Del Shannon
It takes an iron man to play with a toy iron horse.
Well done, Mr. B.
I can hear that organ playing like crazy.
Rich
Alton Junction
Dean
30 years 1:1 Canadian Pacific.....now switching in HO
I'm more inclined to believe a runway that then never responds is caused either by a decoder failure or a scrambled program. The typical "see DC on the rails and take off" type of runaway stops when you cut power, and when you restore power, it goes back to normal, until it 'sees' DC again and takes off. It doesn't completely stop responding until a reset is done. The poitn fo failure for a Dc runaway is ually different too - a stopped loco that is not selected on any throttle is usually what runs away, either on initial powerup or after a short shuts down the booster. I don't think I've ever seen a loco that was already running suddenly take off, other than if it first suddenly stopped (a short).
Reset is always the first step though. Could just be scrambled. The main clue though, is it was fine until the trainw as made bigger - more current draw. Except that unless there is a fault in the loco, it shouldn't be capable of drawing more current than the decoder is rated to supply.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Mr B
Randy, I was wondering if the 4 extra cars caused the problem to began with, but it really did not seem to need extra power. My normal power setting is between 18 and 22 % of the throttle. I did not have to up the power when I added the 4 coal cars.
Will, when all else fails, CV 8 To 8. And disable DC mode.
Thanks you all for your time and song.
MisterBeasley As I walk along,I wonder what went wrong,With my train, the coal drag was so long.And as I still walk on,I think of MUs I've doneTogether, a-while their bells were rung... I'm a-walkin' with my train,Round the loop, and then round again,Wishin' it would stay by me,To end this mysteryAnd I wonder--I wah-wah-wah-wah-wonder,Why,Why, why, why, why, why it ran away,Yes, and I wonder,A-what CV,Will end this runaway,Run, run, run, run, runaway. with apologies to Del Shannon
Thanks for the chuckle Mr. B
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
http://gearedsteam.blogspot.com/
Dang, I only have one engine that I could plug the Decoder into. It is a sidelined PK2000 E 6. It is sidelined do to running very slow, think the grease as turned into goo in the trucks. But that is another story.
Could not get a reading from the decoder using Decoder Pro. So I guess the decoder is dead.
Any other ideas?
Ken But first decoder I have lost in some time.
Try program on the main with the motor decoder plugged into the Blueline decoder. Always works for me. The program track on most systems will not read or write Blueline/motor decoders. My old Power Cab is the only one I have seen that does.
Stay away from the lock features. CV15 and 16. This will only mess you up later.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
How many throtles do you have hooked up to the command station? If more than one, is it the same throttle being used both times? If not, check the other throttle(s) to make sure the engine in question is not dialed in on one of them. If 2 or more throttles are used, and the engine is not dispatched properly, run away locos are the result. Joe.
Just a little up date, Randy was right. Decoder is dead. Did not melt and it does not smell burnt but decoder pro cannot read it.