As mentioned in earlier posts, I am in th midst of building a larger layout. I have one section nearly complete. The target environment will be DCC, but I was thinking about hooking up a DC power supply and using DC locomotive to test the wiring. Reasonable approach?
Richard
I prefer to test with a meter, but your approach should work, too. Use a fussy steam engine so you can test your trackwork at the same time.
It takes an iron man to play with a toy iron horse.
Richard,
Absolutely, do it. In fact, I advise testing every small section of track as you build it. If you anticipate DCC control, most do not add that many electrical blocks like with DC. That means it's a lot harder to isolate where a short is. So testing as you add portions of track is highly advisable. But you don't need to have the power on, as I will explain.
Your testing will reveal any wiring abnormalities, esepcially if you can install and wire your turnouts' switch machines. You should test these on all possible routes through them by throwing them every way they will go (keeping in mind 3-way and slip switches) with power on the tracks.
This way, you test what you just did with the memories of what you did fresh. This makes troubleshooting much easier.
So, no power needed? Not if you have one of those multimeters with the circuits that gives an audble signal if there is continuity between two different points. Here, those points are the two rails. They MUST be isolated from each other and under your control. With track power off, you simply touch the two leads to the opposing rails. You should get no sound, which means that things are good and the rails are isolated from each other.
It the buzzer sounds, then it's time for trouble shooting. What was the last thing you did? Did it work before that? etc. Look over your connections and wiring. Then try again until you hear nothing. Make sure you cover all the potential routes through the turnouts.
There's just lots of places where a misconnected wire can cause a headache. If that happens and is not obvious, try shutting down section of the layout until the short is solved and the command station restores power to the rails or your DC power pack no longer indicqates a short.
Once you're pretty sure the power to the rails is good, then take your engine and run it around. That will tell you about how the rails and the motive power interact, where you may have to make a few other adjustments.
Basically, test continually as you go and the process builds on itself as you gain confidence in finding and fixing problems. That's a lot better than waiting, finding out there are dozens of problems and then just giving up. More than one person has done that, but it's easy to avoid getting in that position by reviewing your work in small, easy to diagnose pieces.
Mike Lehman
Urbana, IL
Some have used a buzzer from Rat Shack with a nine volt battery connected to the main feed point. As they install track, the buzzer will activate with any short.
I have used digital meters from Harbor Freight for years.
Rich
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.
As long as you have no reverse loops, you can connect a DC pack in place of the DCC system and you should be able to run a DC loco anywhere on the layout. Autoreversers do not work with DC, so you will not be able to traverse any reverse sections while doing this.
But, a battery and buzzer, or a meter set for continuity, or ohms if it doesn;t have a dedicated continuity test, connected where the DCC system connects will quickly prove out any shorts in the layout wiring. If the buzzer doesn;t sound, or the meter indicates open circuit, you can connect the DCC system and not have it short the instant the power is turned on.
I test as I go - but I switch between multiple activities while I build, I don;t 100% complete the benchwork, then 100% complete the roadbed, then 100% complete the track, etc. Soon as I have enough track down to run back and forth, even if I have to apply power via clip leads, I have trains moving over the track, on DCC. As I add more track, I test run trains over it to make sure it's all nice and smooth. Once I have enough track, I'll run some bus wires and attach a few feeders and start powering it that way. Add more track - connect the feeders, test, then move on to the next section. By the time I put in the last bits of mainline track, everything up to that point has been well tested, so my first complete run is somewhat anticlimatic since I already know the majority of it runs fine.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
richg1998Some have used a buzzer from Rat Shack with a nine volt battery connected to the main feed point. As they install track, the buzzer will activate with any short.
Yeah, good point. You can also get clips for your multimeter probes that will have it do the same thing. Either way, hook it up to the section you're working in and test for shorts.
I'm a little dyslexic, so a good time to point out that if your connection is wrong, i.e. showing a short, reversing the leads will usually solve your problem. Hooking up the live frog on a Tortoise is a good example. Depending on which way it's thrown it feeds the frog alternatively with either the red or black wire. I hook it up to my best guesstimate and test. If it buzzes, reverse the leads and you're good.
What's the advantage of testing an intended DCC layout with a DC loco and a DCC power supply. Why not just hook up the DCC system and run a DCC loco? That way, you test not only your wiring but the DCC system as well. That's the way I did it. To me, it makes no sense to test a DCC layout in DC mode.
Alton Junction
Not sure I'd say there's an advanatage in testing what will be a DCC system with DC. It's just something that could turn out to be convenient. And as I've noted, you really don't need any power at all, just be able to check continuity.
Either continuity, DC or DCC will test the track wiring. If there is a wired, walkaround control DCC system that's going to be installed, it wouldn't need to be done just so you could attach and control a command station. Just hook up your power pack. With wireless DCC, less wiring issues, but you'd have to hook up all the components temporarily to check them out and use them.
There's also the possibility you're still saving for the big command station and boosters you've always dreamed of. The DC power pack will handle any power needs until your frugality pays off.
Obviously, testing for some of the DCC specific performance of the system will have to wait with only DC, but the basic wiring would be good if tested with DC. You could check that a reverse loop was properly isolated, but not how it would act with the auto revereser; you'd have to have a DPDT switch temporarily installed to use it for that, for instance, if you designed things to work that way.
Of course, this is a good time to remind that you're better off never mixing DC and DCC on a live layout where locos could pass from one system to the other. That's a recipe spelled disaster and has resulted in letting the smoke out. So either all DC or all DCC is the safest plan or take precautions against undersireable interaction.
Not sure about this, but aren't turnouts more finicky on a DCC layout than a DC layout?
If so, that would be another reason to test in DCC mode.
richhotrain What's the advantage of testing an intended DCC layout with a DC loco and a DCC power supply. Why not just hook up the DCC system and run a DCC loco? That way, you test not only your wiring but the DCC system as well. That's the way I did it. To me, it makes no sense to test a DCC layout in DC mode. Rich
The biggest advantage is that I have a couple of extra DC power supplies laying around. I only have the one DCC system and it is attached to my little layout.
The layout is very straight-forward with no reversing loops. It could be either DCC or DC. The section I have completed and want to test is a switching yard with eight turnouts, including one 3-way turnout that I had creatively wire to route the correct power to the frog. I want to make sure it all works. I will first test with a meter, but then wanted a final test with a locomotive. Besides, it is much more fulfilling to watch a train, than a digital meter.
richhotrainNot sure about this, but aren't turnouts more finicky on a DCC layout than a DC layout?
Well, there is all that "DCC friendly" talk, but it's really nothing except having a live frog that's isolated as closely to it on the track as possible. In other words, not a power routing turnout, but one where the power routing is confined to the turnout itself and all track beyond is live and under continuous DCC control, rather than being swicthed back and forth as the turnout is thrown. That way you have max freedom to run as close to other units and their trains as possible.
The only potential issue are shorts as the turnouts are thrown. Depending on the power pack being used it may react differently than a DCC system with circuit breakers when they move. They may just keep going and ignore any shorting, while a DCC system might shut down because its short protection is gentler and more sensitive. So it would be advisable to recheck how they throw once on DCC and readjust any whose throws don't past muster without a shutdown. Howvever, you could certainly confirm all the basic operations with DC power.
RideOnRoadBesides, it is much more fulfilling to watch a train, than a digital meter.
In this hobby, that's enough reason in my book
You said the magic word. Frog. If your installation includes powering your frogs, you really want to use a meter. Most of the time, running a locomotive over your track will work fine even with dead frogs. So, you need a meter to really prove that the frog is powered, however the turnout itself is lined.
RideOnRoadI only have the one DCC system and it is attached to my little layout.
One often overlooked feature of DCC is that you can attach and run more than one layout. Just don't ask it to run more loco's than it's rated for.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
carl425 RideOnRoad I only have the one DCC system and it is attached to my little layout.
RideOnRoad I only have the one DCC system and it is attached to my little layout.
Ah, but the section I am building is is the garage and the little layout is in the home office. It is a little far. Once I move it into the same room, my plan is to use the DCC system on both.
RideOnRoad carl425 RideOnRoad I only have the one DCC system and it is attached to my little layout. Ah, but the section I am building is is the garage and the little layout is in the home office. It is a little far. Once I move it into the same room, my plan is to use the DCC system on both.
DCC Friendly on a turnout has much more to do with the point rails matching polarity of the neighboring stock rail, so any shift in the wheels that might make a wheel rolling on the point rail touch the adjacent stock rail won't cause a short. To make that work, there always has to be gaps between the closure rails and the frog, because they will always be at opposite polarity. It can also work if the open point rail is not connected to anything, thus a connection between it and the adjacent stock rail won't do anything, same as if they were both the same polarity. This also means the throwbar must be insulated or gappes, because the two point rails will have opposite polarity.
Just gapping around the frog, but having both point rails electrically connected via an uninsulated throwbar would not be DCC friendly.
Properly gauged wheels that meet NMRA specs, along with turnouts that also do, and are properly gauged as well, makes nearly everything DCC Friendly since it should not be possible for fully in spec wheels and trackwork to allow such shorting behavior between the point rails and the stock rails. However, the NMRA spec for the gap betwene point and stock rails is much greater than prototype measurements. Making the turnout DCC friendly allows this gap to be more prototypical (smaller) yet still reliable. It's fairly obvious if you look at an NMRA turnout vs one built to finescale standards.
richhotrain RideOnRoad carl425 RideOnRoad I only have the one DCC system and it is attached to my little layout. Ah, but the section I am building is is the garage and the little layout is in the home office. It is a little far. Once I move it into the same room, my plan is to use the DCC system on both. Just go wireless! Rich
Just go wireless!
Where can I get one of those wireless power relays?
RideOnRoad Where can I get one of those wireless power relays?
Well if his DCC system is in the office connected to that layout, and the layout he wants to test is in the garage, he needs to get DCC power there, not just the throttle signal. Wireless throttles won't help here.
It was a futile attempt at humor. As Randy said, it is in a different room so I need some form of power for the layout, thus the thought to use an extra DC power supply.
As an aside, I can't seem to get the "Add Quote to Post" function to work. It is no longer showing up as a button, but as a hyperlink that does nothing.
rrinker Well if his DCC system is in the office connected to that layout, and the layout he wants to test is in the garage, he needs to get DCC power there, not just the throttle signal. Wireless throttles won't help here. --Randy
rrinkerProperly gauged wheels that meet NMRA specs, along with turnouts that also do, and are properly gauged as well, makes nearly everything DCC Friendly since it should not be possible for fully in spec wheels and trackwork to allow such shorting behavior between the point rails and the stock rails. However, the NMRA spec for the gap betwene point and stock rails is much greater than prototype measurements. Making the turnout DCC friendly allows this gap to be more prototypical (smaller) yet still reliable. It's fairly obvious if you look at an NMRA turnout vs one built to finescale standards.
Randy,
I guess this is where I always ask, once your frog is squared away, what's the big deal about "DCC-friendly"? Heck, even the live frog is soemthing I dod in narrowgauge on DC just as good practice. I do my best in checking and correcting various issues with turnouts per the NMRA gauge and that usually results in trouble free operation. I tend to think that's what we all do, although YMMV. I am aware that some give no thought to such things and suffer for it, but that's like a lot of things in life.
I don't disagree with most what you're saying, it's just that I assume that's what you do when maintaining track anyway, so it's, if I may, "DC-friendly," too?
The one thing you introduced I'm not sure of is the fine-scale standards vs "DCC-friendly." I can understand how reducing that gap could be considered "friendly" if your car fleet's trucks were recent vintage. But a lot of older brass trucks like we have in HOn3 might not find that so friendly, I suspect, although never tried that here. I've just never heard the finescale standards cited as part of DCC-friendlizing process. Then again, I don't lay much track, but can tell if stuff is rolling through or sparking. I just don't recall significant track revisions from people claiming to make their layouts DCC-friendly
I am pretty much done with insualted frogs anyway, all of mine will be powered from here on out - though I really have had no problems with Atlas turnouts over the years, mainly because I power them from all 3 sides, even my smallest locos don't lose power even though I ran wires to the frogs but never hooked them to anything.
However - it is those wide wheels spanning the point to stock rail that cause the shorts in non-DCC friendly turnoutes, because they are opposite polarity. In a DCC friendly turnout, they are the same polarity, so even with a smaller, more prototypical gap there, if the wheel DOES touch, nothing will happen, you're just connecting a rail that is + to another rail that is +.
Of course if it's DCC friendly then it is also DC friendly. The opposite is not strictly true - the usual type of short protection used in DC power packs is slow acting, so a brief spark won;t trip it, and the momentum of the train can easily carry it past the shorting spot - it doesn;t have to be far - or even just the bit of slack running in at the moment of stall can turn the offending truck enough to clear the short, and the train continues on. You might see the headlight flicker at worst. With DCC, the short protection is almost always electronic and very fast acting - so even that momentary blip is enough to cause the whole thing to shut down - which is why you break the layout into seperate districts with their own breakers so you don;t take down the entire layout.
Now, if both point rails, and the corresponding closure rails, have polarities matching the adjecent stock rails, clearly this means you need a gap in the closure rails before the frog, ala Electrofrog or the cuts shown for Fast Tracks turnouts. Or you need an all-plastic frog ala Atlas Snap-Track. It's the former that drives the latter - you can insulate the frog, but still have the point rails tied together rather than matching the adjacent stock rails
People usually don;t have to change anything when switching to DCC - if they used Atlas track, it already meets the "DCC Friendly" criteria, and if they have wheels and track all in gauge and run modern wheel profiles, you shouldn't get the shorts even in other turnouts that aren't wired DCC Friendly.
Finescale standards aren;t part of making things DCC Friendly - what I meant was that by making the turnout DCC Friendly, you can make the open point gap much smaller, LIKE finescale standards. Standard wheels won;t work reliably through finescale standard turnouts, but if you look at the typical 'standard' prefab turnout, the gap is usually VERY large. If you didn;t have to worry about occasional back of wheel contact, you can make it smaller, closer but not fully finescale, and still get reliable operation from standard size wheels. And it will look better - it's one of those dead giveaways if a picture is a model or the real thing, if there is a turnout in the picture.
OK, that's much clearer and pretty much what I practice, as much as one can with RTR Shinohara.One thing you can do with them is to reshape the points carefully, so those locos would otherwise touch the point that's floating on its way through with the back of the drivers can't touch it. But that just widens things usually where you want to be closing them. I've thought about isolating the points but with over 100 installed, that's also an idea for a future layout, should that become necessary.
Shinohara HO-HOn3 turnouts suffer from a bit of sloppiness through the frogs that I notice mostly because of the way cars tend to lurch their way over that. But 25 years ago, I felt lucky to have RTR dual-gauge available. In a do-over, it'd most likely be FastTracks, with ME flex in between. I wouldn't mind spiking the turnouts, but I'm not a glutton for punishment.
Certainly, powering those frogs is the best thing since sliced bread if you are having contact problems through a turnout with short wheelbase locos. With the relative lightness of HOn3, we just need every elctrical advantage we can get, so that's why I was down with doing that from the get-go.
Been in model railroading since the 1950;s. Have lost track of how many wired a layout, hooked up the power pack, short somewhere.
I am still seeing this, mostly with DCC. Especially when the layout was working and a new section was added and not being check consistently. Those who have never experienced this might not understand. Not every modeler is electrically savvy.
Best to test as you go. Much simpler to troubleshoot the section you just wired then the whole layout. Any type of power will do for testing. A short is a short. 9 volt battery terminals fit easily on N scale track. I've even use my auto jump box for testing.
Martin Myers
One thing that I have to say about laying track on an intended DCC layout and wiring it is that little can go wrong unless you cross feeder wires along the way.
Lets say that you decide to use red feeder wires on the outside rail and black feeder wires on the inside rail. If you are not wiring power districts or reversing sections, there really isn't much that can go wrong unless you reverse the feeders as you go along.
So, the best way to do this is to first string your bus wires, connect the bus to the DCC command center, lay track and drop feeders as you go. What is so complicated about that?