Do you have styrene in your gaps for the programming track? I would also reccommend that you have a dead section (isolated on both ends) between the programming track and the main. If it must absolutely be powered a SPDT switch to swap power on the isolated section between programming track and main would not hurt.
Also I have seen a BLI PRR T-1 smoke its decoder after de-railing, however it was shorting for a full 30 seconds before anyone could get to it. The decoder died because of insufficient power drops to trip the breaker (nearest was about 5 feet away on un-soldered track).
However the best option is to completely separate the programming track from the layout. A portable one might be a good idea if your workbench is not co-located with your layout.
cn1762...One other thing I hadn't mentioned earlier was that I also use a Lenz Black Box for programming...
Well, that is interesting. I couldn't find much information on the Blackbox programmer, but Tony's Train Exchange does say "Allows programming of high in-rush current sound decoders." If that is the case, I wonder if it could also allow enough current to blow a decoder.
cn1762 I sent the decoder back to the dealer that I bought it from. They sent me a replacement which I installed and programmed without issue.
I sent the decoder back to the dealer that I bought it from. They sent me a replacement which I installed and programmed without issue.
Since the replacement decoder works fine, that would seem to eliminate the programming track as a culprit.
Thanks for getting back to us on this issue.
Rich
Alton Junction
richhotrain cacole Feeding us little bits and pieces of information about your system and what actually happened is not helping matters, either. For example, you wrote that you saw smoke coming from the decoder; now you say there was no smoke. I have to agree that this thread is headed toward a no-decision bout. Aside from the smoke vs. non-smoke issue, the implication remains that a cracked gear fried the decoder. But, no one else seems to think that this is the case. Has the OP verified that the decoder is fried? Rich
cacole Feeding us little bits and pieces of information about your system and what actually happened is not helping matters, either. For example, you wrote that you saw smoke coming from the decoder; now you say there was no smoke.
Feeding us little bits and pieces of information about your system and what actually happened is not helping matters, either. For example, you wrote that you saw smoke coming from the decoder; now you say there was no smoke.
I have to agree that this thread is headed toward a no-decision bout.
Aside from the smoke vs. non-smoke issue, the implication remains that a cracked gear fried the decoder.
But, no one else seems to think that this is the case.
Has the OP verified that the decoder is fried?
As for verifying if the decoder is fried or not all I can say is my system would not recognize it and once the short was found and the new decoder installed all was fine again.
I shipped the decoder back to the dealer who will send it back to TCS for repair or replacement.
cacole Does this "Lenz Black Box" have an internal circuit breaker to shut power off if a short is detected in the programming track? I think you have a major problem on your hands with Lenz equipment not properly protecting the decoder, or you don't have your programming track totally isolated from the rest of your layout like you think it is. Feeding us little bits and pieces of information about your system and what actually happened is not helping matters, either. For example, you wrote that you saw smoke coming from the decoder; now you say there was no smoke.
Does this "Lenz Black Box" have an internal circuit breaker to shut power off if a short is detected in the programming track?
I think you have a major problem on your hands with Lenz equipment not properly protecting the decoder, or you don't have your programming track totally isolated from the rest of your layout like you think it is.
Whatever became of the decoder?
No I never actually saw any smoke from the decoder. What I did notice was a little blister on the plastic wrap over the decoder. This led me to believe the decoder was fried. That and the computer's JMRI screen was reading no locomotive detected.
One other thing I hadn't mentioned earlier was that I also use a Lenz Black Box for programming so there is not way there could be a wiring issue with the layout. The only thing is that the programming track is located on the layout and is isolated from the rest of the layout.
cn1762...Then poof! The magic smoke came out...
From this, I'm thinking that you actually saw the smoke and assumed the decoder was toast. If your program track is current limited,then the limit should be 250ma, not enough to smoke the decoder, but probably enough to smoke a lighting output.
cn1762...After lots of checking I discovered that the new wheelsets I purchased because of cracked gears were causing a short. It appears the axle ends were touching inside the gear...
So here's my theory: Originally the wheelsets were not creating a short(again, if they were the decoder should not have gotten any power). There was a wiring misshap or faulty decoder that caused a short on one of the lighting outputs. This short blew the lighting ouput, resulting in the smoke. Realizing something was wrong you started checking things and in the process caused the axle ends (which must have been awfully close to begin with) to come in contact with each other creating the short that you assumed was the orginal problem.
I could be way off with my theory, but I just don't see how shorting the wheels together could blow the decoder. If it could, we would have blown decoders all the time from people running a switch the wrong way and from derailments that cause a short.
richhotrain I have never heard a convincing reason to install the programming track on the layout, isolated or not. I think that the best advice is a totally separate programming track on the work bench. No chance for error. Rich
I have never heard a convincing reason to install the programming track on the layout, isolated or not.
I think that the best advice is a totally separate programming track on the work bench.
No chance for error.
I agree with you 100%
Jack W.
cn1762 The programming track is part of the layout but isolated electically by a 2 mm gap in each rail. The only wires being the wires to the Lenz programmer.
The programming track is part of the layout but isolated electically by a 2 mm gap in each rail.
The only wires being the wires to the Lenz programmer.
This is not enough, you need dead zone between the programming track and the layout.
See this link http://www.wiringfordcc.com/track_2.htm#d2
With no locomotive on the programming track, take a voltage reading and see what you get. If there is any voltage at all on it, your system has developed a serious problem.
[/quote]
I have to agree. Check the voltage. Something isn't right here.
Yes I am sure of that. Unless my meter lies to me.
I guess I will just chalk it up to one of those brain fart moments.
Should of checked the wheels!
How is your programming track set up?
Is it separate from the layout?
Is is on the layout but isolated?
All true, but even if the loco was set on the main track with power on, it should have simply shorted through the axles. With the stub axles pushed in so far that they touch back to back inside the gear, there shouldn;t be any current flowing through the decoder, especially not from the track input to the motor output which is generally what fries things.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I think there is something wrong with your programming track wiring -- there should never be enough voltage available on it to damage a decoder. I would be checking the wiring between the Lenz system and the programming track looking for something connected to a wrong terminal. The programming track should not even have any voltage applied to it unless the system is actually trying to program one of the CVs. and then only in a short burst of low amperage -- and the system should have immediately indicated a short and shut down.
The decoder was a TCS decoder and yes the motor leads were isolated. And the bottom of the motor was isolated from the frame as well. The replacement worked fine once I made sure there was no more short curcuit. Just can't figure out why it fried on the programming track.
If a meter set to ohms was applied to the motor leads, this could be enough to fry the output stage - a meter set to ohms is applyign a voltage across th probes in order to measure the resistence between them. Just a possibilty. Applied across the wheels, or the track pickup wires, it should have instantly indicated a short.
Just a guess. If the short was intermittent, the DCC voltage might have surged high enough to smoke something. Look at the decoder, what smoked, the full wave bridge?
Since you have done decoders before, are you sure nothing could touch the two motor leads?
A photo of the decoder would be nice unless you can get a free replacement.
Wonder what the replacement is like for this brand of decoder.
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
A little more information on my original post. I have a Lenz system and use JMRI on my computer for all programming. And yes the locomotive worked before the conversion but with the klunk of a split gear. I have installed this type of decoder in older Life Like and Athearn units before without issue. I can't explain why it smoked on the programming track. I know it shouldn't. I used my ohm meter after the fact and read the dead short and began the process of elimination before installing a new decoder. It wasn't until I removed the truck assembly from the frame and removed the wheel sets and discovered the source of my short.
Something is definitely amiss with the DCC system if it did not shut down because of the short circuit caused by the wheel axles touching. Even if this had been on the main line, the DCC system should never have allowed an attempt at programming and should have shut down the entire layout.
rrinker... I'm not sure how a short across the rails can smoke a decoder though. The way decoders smoke is when the motor leads cross connect to the track power. A short on the rails just means no power is going to the decoder at all...
That is what I was going to mention. If you smoked the decoder there must have been something else wrong other than just the wheels shorting out.
wjstix Ya, normally when I install a decoder, the first thing I do is put it on the programming track and try to read back a CV. If it doesn't work, I know something is wrong. Programming tracks normally don't have enough power to 'fry' a decoder, which is I why I try it on the programming track first.
Ya, normally when I install a decoder, the first thing I do is put it on the programming track and try to read back a CV. If it doesn't work, I know something is wrong. Programming tracks normally don't have enough power to 'fry' a decoder, which is I why I try it on the programming track first.
Read all the OP's message. He says he used the programming track.
This doesn't add up.
Frying a decoder on the Programming Track?
Is that possible?
Before I install a decoder, I test the loco on a stretch of DC-powered track.
Then, I test the decoder with my decoder tester (NCE DTK) on the work bench.
Then, I install the decoder and test it on the Programming Track.