Inexplicable Short Circuit


P

PMW

Well-Known Member
The title of this post is inexplicable short circuit, that refers only to my inability to explain what's going on. I'm hoping someone here can offer some thoughts.

I have two new Athearn Genesis engines. One of which is packed up and ready to go back to Athearn for repair because after working fine for a few weeks it began to trip my circuit breakers every time I increased to speed step one. My other one just started doing the same thing!

I also have a Broadway Limited engine that did the same thing but that one seemed to "fix" itself and has been running fine for a little while now.

These models are not the most inexpensive models available and it seems incomprehensible that they are so prone to this problem. Is it my layout?

I have a spare bedroom sized layout containing two power districts. Both are powered by an NCE Smart Booster 5 and each has an NCE EB 1 circuit breaker between the bus line and the SB 5.

The engines worked great out of the box but within weeks both started doing this. The BLI loco had the problem too briefly but works now. I have no idea why.

Does anyone have any thoughts?

Thanks
Paul
 
Did the motors or axles pick metal shavings/filings, steel wool? You just have the three engines that all have the same problem? Do they short when sitting still? If sitting still, will the lights work? A photo of the layout where they short? Can you connect a test track separate from the layout and see if they short there? Or try them on analog? If you have a meter, can you measure a short across the locomotive when not on the track?
 
My first thought as well was is it the same area where it happens?
And can you set up a small loop of track to let them run disconnected from the layout?
 
I had same issues with 3 of my engines. The solution for mine was use no-ox on the trucks and wipers. My engine has stopped the shorts and intermittent of the engine. Not sure if that is the same on yours but afterwords i cleaned the trucks on my engine cleaner and that took the excess fluid off. Its been a week or more and no more issues since. Hope this can work for you as i too was ready to send mine back to Atlas and the other two to BLI for repairs.
 
Thanks for the replies! I've been trouble shooting for hours! Firstly I can say the short circuits happen in several different places and in each power district.

I didn't have enough track for a complete loop but I did have about 4 ft. I hooked up to my booster with a circuit breaker between. Intermittent short circuits would still occur. I began to suspect the circuit breaker. I removed it and did not have any shorts but that was only on 4 ft. of track, not a great test.

I connected the mainline bus line to the booster without the circuit breaker and left the circuit breaker between the booster and yard bus line. I have not had a single short on the mainline but am still reliably having shorts in the yard! I've only been running the engines on the layout this way for a few hours but given the way the engines were running I strongly suspect the circuit breakers. The question now is what went wrong with the circuit breakers (if they are indeed the culprit)?

I had no problem with the breakers when I first installed them. While trying to figure out how to wire my auto reverser I changed the trip current settings on the breakers. Could I have screwed something up. I've returned them to the factory trip current but maybe there is a way to reset them with my dcc system?

My next step will be to remove the circuit breaker for the yard too and see if the shorts go away there also. I figured I'd post this before I ran with no short protection at all.

Well, that's where I am presently :confused:. Please let me know if you have any thoughts and thanks so much for your help!

Paul
 
PMW said:
I had no problem with the breakers when I first installed them. While trying to figure out how to wire my auto reverser I changed the trip current settings on the breakers. Could I have screwed something up. I've returned them to the factory trip current but maybe there is a way to reset them with my dcc system?
Click to expand...

It possible that by changing the trip setting that was the problem. It was set too sensitive. I would run the system without the breakers since most DCC systems have build in breakers. Besides, it's likely you'll be running the layout as a solo operator most of the time so a system shut down isn't the end of the world. 🤒
 
Last edited:
It's either the throttle shorting inside it or the added circuit breakers need to be adjusted. It's extremely unlikely, something like 0.5% or less, that three different locomotives would all be acting up the same way and it's all due to them and not something more common about how they are used and powered.
 
Thanks, Greg. I'm not sure if my booster has a built in breaker but even if it does running without the circuit breakers is a temporary solution.

I'll contact NCE and explain the situation after I run without both breakers. If I don't have any shorts on the main or in the yard after that I think I can conclude the problem is the breakers. I don't know if I fried the breakers but even if I did I'll be happy to replace them and get out of this for 40 bucks!

Thanks
Paul
 
Selector said:
It's either the throttle shorting inside it or the added circuit breakers need to be adjusted. It's extremely unlikely, something like 0.5% or less, that three different locomotives would all be acting up the same way and it's all due to them and not something more common about how they are used and powered.
Click to expand...

Thanks. I agree that it's unlikely that the new engines all have the same problem. I'm happy to have found a plausible solution other than all the engines I bought are crap 😀

Am I right by "the throttle shorting inside" you are referring to the hand held cab? If so I don't believe so given the shorts on the mainline seem to be gone after being almost constant. We'll see what happens soon when I disconnect the other breaker.

Thanks
Paul
 
I disconnected the other circuit breaker and no engine has caused a short since. It's only been several hours but the overt difference removing the circuit breakers makes leads me to think they are the problem.

I'll dig into the EB 1's manual to see what I can find and if I have to I'll contact NCE. If anyone has any idea about what seems to be happening please reply.

I do seem to be on my way to getting past yet another beginner's Gordian Knot :)
 
" The SB5 now includes a P514 Internationally approved Power Supply. The P514 incorporates a internal short circuit protection. See manual for more info. "

In case the circuit breakers need to be in time out for a bit.
 
I would start reading the circuit breaker instructions. There are many settings on the various circuit breakers, some set by jumpers that can be on different pins, some set by adjustable pots, some set by CV's through the DCC system, just depends on the brand of breaker.

I have auto reversers in some blocks and have to set my circuit breakers in those blocks to be slow acting breakers (not fast acting may be a better description) by setting CV's so the AR will trip before the circuit breaker.

I recently had a auto reverser that was giving me no end of problems until I figured out I had forgot to move jumper on the circuit board to configure it for the operation I was wanting. After I set it up the way it was supposed to be it ran flawlessly.
 
I'm no great resource on these electrical problems,...but I seem to recall reading of some problems with these EB circuit breakers (made by NCE?).

I believe I read that the DCCSpecialties breakers were less problematic?

Hope I have not screwed the discussion with incorrect info.
 
PMW said:
Thanks. I agree that it's unlikely that the new engines all have the same problem. I'm happy to have found a plausible solution other than all the engines I bought are crap 😀

Am I right by "the throttle shorting inside" you are referring to the hand held cab? If so I don't believe so given the shorts on the mainline seem to be gone after being almost constant. We'll see what happens soon when I disconnect the other breaker.

Thanks
Paul
Click to expand...

Yes, I agree with you that you appear to have isolated the fault(s) to the circuit breakers if, now that they are not in series, the trains appear to be behaving. I'm happy you persevered and that we talked you down off the ledge...of returning perfectly good locomotives. o_O So, you have a few minutes of reading ahead, after which you may elect not to include the circuit breakers after all. If you do, your reading of their literature should help you to set them up correctly for your needs. Good luck to you.
 
Thanks, Selector. I have run more trains today and no problems!

I'd prefer to have circuit breakers for each district to keep a mainline train going if there's a short in the yard and vice versa. For now it's not a big deal. It's got me really making sure turnouts are properly aligned! That's a good habit anyway.

I don't know where to start on adjusting circuit breaker settings but I will begin my research! I'm wondering if using PSX breakers may work better since I have a PSX auto reverser?

If anyone has a good source of info for this please point me to it :)

I'm sure I'll get there one way or another and I'll let you all know what I learn.

Thanks
Paul
 
I believe Tony's Train Exchange and Digital Specialties (the people who engineered the PSX series and brought them to market) both have resources for the modeler on their sites. Trust me, I'm no slouch mentally, although I'm not clever enough to be an engineer either... :rolleyes: ..but I had to have the Digitrax and Digital Specialties' PSX-AR manuals handy for a few weeks after I began to use them. Eventually it all came second nature. I took my time, exposed myself repeatedly to the material over a few days, and finally it clicked. I don't recall now if I had to tweak the trigger time for the PSX-AR I installed, but I can tell you that it worked flawlessly on two different reversing configurations on two successive layouts. I currently have it stored, unneeded, for my fourth layout, but I wouldn't hesitate to put that wee beastie back into service.

You'll eventually want the circuit breakers to trip a few milliseconds BEFORE the circuit on your DCC base station. This will both protect the affected district and allow the rest of the layout to function. If you have guests, or just have a second train running around not in the affected district, the CB will detect, trip, and keep power from the rails while you detect the location and correct the fault.

Actually, this brings up another factor...quickly locating the affected area. Some rely on a buzzer, but ears aren't great at separating that sound in a small room. Some of us wire a #1159 tail light bulb in series between the bus and the feeders. The bulb is mounted in a hole in the layout's fascia, and when there's a short, the inrush of full amperage lights up the tail light bulb and it glows brightly, indicating where the short is. It also serves, by resisting the current and glowing thereby, to keep the amperage from damaging the decoders in that area. I am not familiar with 'circuit breakers' per se, since I only have the one PSX-AR, which operates silently. Perhaps they already have an indicating LED or something.....
 
Last edited:
Thanks, Selector. I've looked at the PSX manual online. A lot of information in there! One of the things I noted is that you can add an external audio signal to alert of a short.

They are more expensive than the NCE cb but if they are worth it I don't mind paying a little more.
 
The audio alert is no doubt a great first indication that you have a short, but when you go to look.....................where do you look? If your CBs are all mounted in an array, and have an LED indicator as well that lights up or blinks, then you'll soon know where the short it. But a 1159 tail light bulb wired in series will glow and show the fault's location as well.

It's just a thought. I and others have used the bulbs successfully, and they do a good job of both limiting the amperage and keeping things moving elsewhere. That they glow at all also tells you which district has the short.
 
I've been running trains without circuit breakers while trying to figure out how to proceed in respect to the breakers. One of my engines (with a Tsunami 2 deiseal decoder) began to occasionally stop responding to speed step commands and all lights would blink 12 times. This seemed to always happen when going from speed step 2 to 1, 1 to 0 or 0 to 1. After a few seconds the lights would come back on steady and the problem would be gone (until it happened again).

A google search informed me that the 12 blinks is an error code indicating that the engine was subjected to current more than 150% of it's limit (if I understand correctly). I don't know when, how or if this happened.

My other Tsunami 2 decoder equipped engine definitely was subjected to a short when, while running without circuit breakers, it hit a trailing point turnout not aligned. The engine worked briefly after this incident but now does not respond to motor commands and gives the 12 blinks message.
While this is not good at least I have an idea why the decoder is not working properly. I have removed this engine from the layout for now.

Now for what's really got me scratching my head; the first engine I mentioned has now also stopped responding to motor commands and all lights blink 12 times. This engine was on the layout when the other caused a short with the misaligned turnout so was also subjected to the short. However it continued to work until the next day before suddenly not responding to speed step commands.


I would really like to be posting something in my thread over in the "Layout Construction" part of this forum but lately I can't get what I have working as it should so I'm not interested progressing with anything else :confused:

Any thoughts would be very appreciated.

Thanks
Paul
 
Does the command station have different output settings? I use Digitrax and it has a switch for N, HO or O/G and leave it on the HO setting. I've had lots of derailments/shorts in the 20+ years I've been using it but no problems like you describe. If it's a short related to a derailment, the decoder shouldn't see the current, it would be flowing through the derailed wheel. What are the engines in question, you said they were new Genesis but didn't say what model? Have they been collecting dust or hair on the axles and slowly increasing the amount of current they need to move? That could also explain the circuit breaker issue if it was set to just above the current needed when they were brand new.
 
You must log in or register to reply here.



Back
Top