Runaway Train

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#1
I have a BLI 282 PRR steam locomotive with Paragon 3 sound. I use a NCE Powercab controller. I have only owned the loco for a few months and all has been well.

Recently, I noticed that sometimes the loco would bog down slightly, as evidenced by the chuff sound change. I thought it was maybe because it was hauling 20 cars but it would get back to programmed speed quickly.

This started to happen more frequently and finally resulted in the loco almost coming to a stop and then ripping wide open and wouldn't respond quickly to reduction in speed. I contacted BLI and they suggested perhaps some programming flaws were made and to reset the loco by pulling the tender body and accessing the little reset button. Also, to try resetting the controller. I did clean the NS track which wasn't too bad since all my rolling stock has been upgraded to metal wheels.

Any ideas on this runaway train issue? I have read stories of locos returned for repair may not be returned for months.
 

Selector

Active Member
#2
This is an infrequent problem inherent to the digital signal and voltage on which the DCC signals are carried to the rails. Remember that DCC is full voltage all the time. Sometimes a spurious signal convinces the decoder that the voltage is really DC, and the motor responds immediately to what the decoder passes on....full voltage.

Reset your decoder. Change the address and then set CV29 to a value of "34". This setting in CV29 precludes the decoder from "dual mode" capability where the decoder automatically senses which type, DC or DCC, it is receiving from the rails. In fact, with that setting, the decoder cannot run on DC and simply will not respond. This is a cheap form of insurance against runaways.

If this 'fix' should fail to work reliably, return the loco to BLI (seek agreement from them first), or ask them if they'll ship you a new decoder.
 

bnsf971

AKA Gomez Addams
Staff member
#3
I had this problem with a BLI 4-4-4-4, and it turned out the motor was going bad, intermittently drawing too much current and slowing down almost to a stop before taking off again.
 

bnsf971

AKA Gomez Addams
Staff member
#5
Did you send it back to BLI? If so, how long before it was returned?
It is a long story. It blew a decoder. They sent a replacement decoder. It blew that decoder. I sent it back. It came back in 6 weeks with a new decoder and new motor. It ran for 6 months, then blew another decoder. I sent it back. It came back in another 6 weeks with another new decoder and another new motor. It ran a month, then the same thing happened. I sent it back again, and again it came back with a new motor and decoder, as well as all new circuit boards and a complete rewiring job. It ran a year. Same thing. I sold it on Facebook for $50.
Not saying you'd have the same luck, because that was a time I was having a lot of decoder issues that turned out to be a DCC system issue. There is no real telling how many of these were engine/decoder problems, and how many were from my DCC system.
 
#6
Well, my runaway train saga is ongoing. BMI said to reset the decoder and the controller. I did both and the loco seemed to be back in good order. After an hour or so of running over a couple of days, I sensed that slight change in sound indicating a slight speed up and subsequent slowdown. The cycles became more frequent and more intense. I watched the ammeter on the controller and it jumped all over. After one last wide-open "nothing can stop me now" run terminated only by an E-stop.

I contacted BMI and they asked me to check the stall amperage on the motor because anything over 1 amp is toast. The stall amperage was 1.81 then it dropped off to about .37. I got back to them and they said it needed a new motor and new decoder. They are about 15 weeks out on repairs now but I could have the parts in a couple of weeks if I agreed to fix it myself. The decoder is in the tender and is plug and play. The motor requires 2 soldered connections, so it doesn't sound too bad. I really like this loco and couldn't be without it that long. They said they might be able to do a trade-in allowance on a refurbished loco but I'm not interested in that. I will refurbish my own. I will report back after the repair is completed.
 



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