Hi, I'm trying to wire a locomotive I have for DCC. I tested the decoder when I got it and it worked fine sound and everything. But tonight I tried to wire it in my locomotive and I attached the power wires to the pickup wheels and set them on the track to test it before I attached the other wires, and it worked for about 5 seconds but then it started smoking and short circuited my DCC system until I took one of the wheel sets off. I tried it again but it only short curcuits until i take it iff the tracks. anyone have any ideas or tricks that could help
thanks for any help
Hi SOU_RY_modeler:
If the decoder emitted smoke then unfortunately it is probably 'toast'. Pardon the pun. Some manufacturers have 'no questions asked' warranties so you might be able to get it replaced.
It might help if we had a few more details:
- Which locomotive, which decoder, and which DCC system?
- Based on your post, it sounds like you only had the red and black decoder wires hooked up. Is that correct or was the motor hooked up too?
- If the motor was hooked up, did you make sure that the motor contacts were isolated from the locomotive frame?
- Were you using the Program Track or Programming on the Main?
Others may have more questions.
If you can provide pictures of your wiring that might help solve the issue too.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
It sounds like a classic case of trying to convert a DC locomotive to a DCC locomotive. To avoid frying the decoder, the motor must be isolated from not only the frame but also from any and all of the power pickup wheels. Use an ohmmeter to ensure that the two motor leads are completely isolated. The following link provides an excellent discussion of this entire process.
http://www.wiringfordcc.com/locos.htm
As for the decoder, the presence of smoke, the smell of burnt electronics, and a system short add up to a fried decoder. If a perfectly functioning decoder (tested on the work bench) shorts out and smokes immediately upon installation in a DC locomotive (not DCC Ready), it is a sure sign that the motor and brushes were not completely isolated from the frame and any and all power pickup wheels.
One other thing to keep in mind. The decoder itself must be isolated from any source of voltage so that only the rail pickup terminals on the decoder are wired from the power source. So, the decoder board should not be in direct contact with the frame.
Rich
Alton Junction
And if you only onnect the track wires, none oof the other wires can be touch anything - not each other, not the track, not the loco frame, any place they can short.
Though I am not sure why you would want to do that - nothing will actually work properly without a load on the motor wires. You might get some noise, but you can't program anything.
Which brings up the next point - test on the program track FIRST, where the current is limited (depending on the system - those without dedicated program tracks are NOT for beginners). If the loco won't program, there's a wiring fault and it needs to be fixed before putting the loco on the full poower main track.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
What is the loco stalled current at 12 vdc? Most decoders are one amp limit.
Remember, the EZ Command is very limited. You can program loco number and operate a few sounds in a sound decoder. You cannot program any CV's.
There is a way to use the EZ Command as a program track. It is in the manual.
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.
Everything was isolated (no bare wires show except from the wires I'd attache) and I was only testing to see if the decoder worked properly but with everything being disconnected before hand because I'm trying to figure out the motor, because I have to swap it for a can motor and I'm very limited on space. I figured I would wire in everything except the motor and see if it worked but it had these issues with only the speaker and power wires attached to anything. The locomotive originally was all metal and the power went from the track to the tender then to the motor, I swapped out the all metal tender trucks with plastic ones so they would be isolated from the tender and not damage the decoder. When I tested it it hummed until I rolled the wheels slightly then I got it to whistle and the bell to ring but after that it hummed and started smoking when I tried to test the syncronized chuff sounds.
richg1998Remember, the EZ Command is very limited. You can program loco number and operate a few sounds in a sound decoder. You cannot program any CV's.
I know it's limited but I'm not using it on a major layout it's just a simple one for just me
Really a mystery if only the red and black wires connected to the track. No lights or motor connection if I see this correctly.
Orange, grey, white, yellow and blue wires not connected to anything.
I would say a defective decoder. I have never tried a decoder like that. Always connect at least a motor for a load. I have used a 100 ohm, 1/2 watt resistor for a load a couple times just to see if the decoder would respond.
My first decoder tester ws a green, red bi-color LED with a resistor before I found an old can motor.
Could be a bad decoder, but seems to me that there had to be a wire touching somethign it shouldn't, considerign the sequence of events. All was fine with the throttle turned off (so no motor output). Then when the throttle was increased - poof. Tells me the orange and grey were touching each other or one of them was touching the rail or the loco frame, more likely the former since a motor wire to track side smokes the decoder as soon as track power is turned on usually.
SOU_RY_modeler I tested the decoder when I got it and it worked fine sound and everything. But tonight I tried to wire it in my locomotive and I attached the power wires to the pickup wheels and set them on the track to test it before I attached the other wires, and it worked for about 5 seconds but then it started smoking and short circuited my DCC system until I took one of the wheel sets off.
I tested the decoder when I got it and it worked fine sound and everything. But tonight I tried to wire it in my locomotive and I attached the power wires to the pickup wheels and set them on the track to test it before I attached the other wires, and it worked for about 5 seconds but then it started smoking and short circuited my DCC system until I took one of the wheel sets off.
The EZ Command does not have a high enough voltage to smoke a decoder.
richg1998 The EZ Command does not have a high enough voltage to smoke a decoder. Rich
rrinkerbut seems to me that there had to be a wire touching somethign it shouldn't
I didn't have it fully wired in, I just had the decoder setting inside the tender shell and the rest of the wires spread out except for the power wires that I soldered to the pickup wheels that I had setting on the track. I've been messing with is a little and to me it seems weird that it short circuits the EZ command as soon as I set the wheels on the track. I know one side is for power pickup and the other is insulated because it test ran fine when I got it before I disassembled it to paint and convert to DCC
SOU_RY_modeler Hi, I'm trying to wire a locomotive I have for DCC. I tested the decoder when I got it and it worked fine sound and everything.
Hi, I'm trying to wire a locomotive I have for DCC. I tested the decoder when I got it and it worked fine sound and everything.
It doesn't test now it just short circuits the EZ command as soon as it makes contact with the rails. But it runs my other DCC locomotives without any issues
SOU_RY_modeler It doesn't test now it just short circuits the EZ command as soon as it makes contact with the rails. But it runs my other DCC locomotives without any issues
richhotrainDo you mean that the EZ Command runs your other DCC locomotives without any issues? I assume that is what you meant
That is telling you, the decoder is toast.
You messages were a little cryptic. See the responses from others.
It appears the blue, white, yellow, orange, grey wires were not connected to the lights and motor so nothing should have shorted the decoder.
You only used the red and black wires to the track.
You can make a simple decoder tester using a 100 ohm, ½ watt resistor across the orange and grey wires to simulate a motor. I have a link somewhere that tells how to adjust the CV’s so as to not overheat the hundred ohm resistor. But for simple testing, that might not be necesary.
A 1k resistor and LED between the blue and white wires and another LED and resistor between the yellow and blue wires.
I have done that and it works very well. Some do that with two decoder installs.
A cheap can motor with a flywheel is better. I found a nice five pole can motor with 1.5mm shaft in an old computer CD player
SOU_RY_modeler richhotrain Do you mean that the EZ Command runs your other DCC locomotives without any issues? I assume that is what you meant yes, exactly what I meant. I don't have the short circuit problem unless I try to test the decoder I'm trying to install
richhotrain Do you mean that the EZ Command runs your other DCC locomotives without any issues? I assume that is what you meant
yes, exactly what I meant. I don't have the short circuit problem unless I try to test the decoder I'm trying to install
Testing a decoder is not accomplished by merely installing it in a locomotive, hoping for the best and fearing the worst. In my case, I own an NCE DTK which is somewhat primitive but it does verify that the decoder works before I install it in a locomotive.
Installing an untested decoder in a DC locomotive that is not verified as DCC Ready is a disaster in the making. But, the real problem here seems to be that the locomotive was not adequately tested to verify that it was DCC Ready. It wasn't and it fried the decoder.
But I don;t think he actually 'installed' the decoder. Per previous messages, all he did was hook up the red and black to the track pickups. The motor wires were not connected and neither were any function wires. The only way that's going to fry anything is if something touches where it shoouldn't, and with a gaggle of looose wires around it's very possible. Even something silly like, was the speaker set down on the track, or the decoder itself - if not shrink wrapped, was it touching the rails or the loco chassis?
Though why a loco was used I'm not sure - you cna just clip lead the red and black to the track. lay out th eother wires and stick a piece of tape over them to they don't move around and accidently touch something. Then test away. I'm noot sure about the "synchronized chuffs" comment - there won't be synchronized anything until the motor is wired in. Unless there is a cam input and a cam installed - which would be a path for frying the decoder is not properly isolated as well.
rrinker But I don;t think he actually 'installed' the decoder. Per previous messages, all he did was hook up the red and black to the track pickups. The motor wires were not connected and neither were any function wires. The only way that's going to fry anything is if something touches where it shoouldn't, and with a gaggle of looose wires around it's very possible. Even something silly like, was the speaker set down on the track, or the decoder itself - if not shrink wrapped, was it touching the rails or the loco chassis?
SOU_RY_modeler I didn't have it fully wired in, I just had the decoder setting inside the tender shell and the rest of the wires spread out except for the power wires that I soldered to the pickup wheels that I had setting on the track.
I didn't have it fully wired in, I just had the decoder setting inside the tender shell and the rest of the wires spread out except for the power wires that I soldered to the pickup wheels that I had setting on the track.
So, he may not have completed the installation, but it sure sounds like he at least partially installed the decoder by placing it inside the tender and wired the pick ups to the decoder. Who knows what happened from there.
SOU_RY_modelerI swapped out the all metal tender trucks with plastic ones so they would be isolated from the tender and not damage the decoder. When I tested it it hummed until I rolled the wheels slightly then I got it to whistle and the bell to ring but after that it hummed and started smoking when I tried to test the syncronized chuff sounds.
Mike
The OP in one message said he had put plastic wheels on the tender. It appears only the loco wheels picked up power.
richg1998 The OP in one message said he had put plastic wheels on the tender. It appears only the loco wheels picked up power. Rich
Yes, I missed that but with a plastic truck, no power conduction even if the wheels were installed opposite. This is assuming no pickups. His descriptions can be confusing from what I am seeing in answers from others.
The OP says no other wires were used except the red and black wires. That would say the decoder just failed. It would be interesting to see what actually burned up on the decoder.
The DCC voltage feeds a full wave bridge rectifier and a portion of the DCC is coupled to the microprocessor via a capcitor.
SOU_RY_modelerThe locomotive originally was all metal and the power went from the track to the tender then to the motor
Its a confusing locomotive, it ran before I tried to make it DCC and when I took it apart the motor was insulated from the frame and it had a wire going from the motor to the tender. before I tested the decoder attatched to the trucks and pickup wheels I directory put the red and black wires on the track and it worked with no issues but when I soldered it to the pickups on the trucks it shorted out the throttle and made the decoder smoke.
My best guess is that you fried the decoder because the locomotive was not completely converted to "DCC Ready" status. I would bet that if you removed the damaged decoder, the locomotive would run once again on a DC powered track.