While it's not a bad idea to check voltage to make sure it's the same all over the layout, in itself measuring the voltage doesn't really prove anything other than that there is SOME power source available. Here's why. A multimeter measuring volts is (hopefully - but yes, even the cheap HF meters meet this) a very high impedence 'load'. The idea ot to have as little effect on the curcuit under test as possible. As a high impedence load, that means very little current flows in to the meter. Perfect for measuring voltage of a circuit - if the meter drew 10 amps you can see how that would affect the voltage measurement. bad for determining adequate feeders though. Say there's a questionable rail joiner. With almost no current flowing through the poor connection, the voltage reads the same as it does ont he other side of the joint. However, put a significant load, say a locomotive, on the far side of that joint, and the resistence of that poor joint makes itself known as a voltage drop (and thus a slowdown or stall of the loco). Witht he quarter test, you are creating a short across the rails, although not a zero ohm short like putting a piece of wire or holding a screwdriver across the rails. This means the quarter across the rails (do not press down on it) draws prettyt many amps but not the 'infinite' a 0 ohm short would be. Combined with the cumulative resistence of the bus wires and any rail joiners and feeders between the quarter and the booster or circuit breaker, this still should be greater than the threshold to trip said breaker. Add in a poor rail joiner where there might be a 2 or 3 volt loss at a 4 amp load, and now the current flowing through the quarter and the bad joint and the rest of the wire isn't enough to actually trip the breaker.
Re-arranging Ohm's law, at 15V, to get enough current to flow to trip a 5 amp breaker, the resistence of everything fromt he source to the point of short has to be no more than 3 ohms. If there is, say 10 ohms of resistence in the track and wiring, the 'short' will only cause 1.5 amps to flow at 15V, and the breaker should never trip, it seeing only half the current it is set to trip at.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
You could add feeders to all four ends of the crossing and then see if that solves the stalling problem.
A GP35 should be able to traverse a 25 degree crossing without stalling. If adding feeders doesn't solve the problem, check to make sure that both the front and rear trucks are powered. Apply power to the loco on a straight stretch of track and then lift the front end. Is there still power to the rear trucks? Set the rear trucks back down on the tracks. Then, lift the rear end and check if there is power to the front trucks. I have had issues on occasion with only the front trucks or only the rear trucks receiving power due to faulty pick up wires. Crossings will expose that problem right away.
Rich
Alton Junction
Thanks guys!! good advice- the track needed a massive cleaning, was very dirty, once I did that, the loco motored right around and all over the layout, I added a couple more feeders around turnout locations just to sure up conductivity to loco passing through to avoid slow downs, only area giving me trouble still, is the atlas 25 degree crossing, I have a 4 axle GP-35 DCC, that seems to stall right on the crossing- should I add feeders at each of the four access points (which have connections on other side of rail joiners heading to the crossing), or connect wires instead the crossing to the rail areas protected by the insulated plastic rail.
Hard to say if you need more feeders or not.
Start first with a good track cleaning, i.e., the rails, and see if that solves the problem.
The real quarter test is to just lay yhe quarter on its side across the rails, no pressing down. The system should trip everywhere you place the quarter. The idea is to simulate more closely what might happen with a dereailed loco where a truck skews sideways, or maybe the leading ot trailing truck of a steam loco - not much weight pressing down on it. It's a high resistence short instead of essentially zero ohms when you press down, or put a piece of wire across the rails. This is the sort of thing that causes problems - if the breaker doesn't trip, you cna be pushing the full booster power through a few ohms, which is many watts of power. This is what heats things up enough to melt plastic. So, clean the track (ditry track can make the quarter test fail too), then just set the quater across the rails in various places and verify that it all shuts down. if not, you probbaly need extra feeders near the spt that it didn;t shut down.
thanks for responding,
all the feeder connections are attached to the BUS wire. when I did the quarter test, the quarter was not laying flat on the track, it was sideways touching both rails.
on the layout there is a mix of sectional and flex track as well as the switches. should I jsut continue to add more feeders to the track?
secondly, I will clean the track, it probably is dirty and since using some flux probably has left some residue, even though i used sandpaper and the fiberglass pen to clean the area before and after soldering
I will get back to you
Geez, I almost forgot about this thread, but I see that the OP is still having problems.
I totally agree with Randy that, if the quarter test consistently shorts the system on every piece of track, the problem is most likely dirty track. Take a bottle of household rubbing alcohol and a cloth and wipe down all of the rails.
As far as the wiring is concerned, for the size layout that you have, the size and type of wiring is adequate. I do not solder my track rails together except on curves to avoid kinks. But I do put feeder wires on every end of every turnout. I solder the feeder wires to the bottom of the rail joiners.
Are all the feeders connected? The one pic shows a bunch of them there, and the one with the train on the track, there's one just ahead of the loco not connected.
If the quarter test passes everywhere, by just sitting the quarter on the rails, NOT pressing down, then the wiring should be good. If you put the quarter down somewhere and it shuts off, yet the loco won't run right at that very same spot, there's another issue. Maybe some dirty track, or the loco itself is a little balky.
did do the quarter test to all parts of the track, the areas that allowed the loco to run and the areas that didn't, every spot I put the quarter on shorted the nce powercab and the screen went blank and reset.
So does that mean all the track is powered?
I don't have any insulated rail joiners, have all metal rail joiners on track, some are soldered and some are not. I have added some updated photos here of feeder locations, soldered feeder and rail, and bus wire. http://www.flickr.com/photos/113749345@N07/
Take your picture you linked with the track diagram, and mark of fon it where you don;t have power. I'm going to guess you have tracks past an insulated joiner that does not have a feeder anywhere. If it's the same one you linked before, there are no reversing sections in there, it's pretty basic.
Hey guys,
just checking back in for some advice, just wired up, what I thought was the correct way, after viewing many videos, reading articles, and following advice on this forum, but still seem to have issues with track power loss. Feel like I'm pretty smart in most respects, ha, but right now this wiring of track has me feeling like a bonafide idiot.
to review, I have a simple 4x8 layout- two ovals, two branches off the inside oval with a cross at a 25 degree, and a small yard. I ran 18G wire, one red, one black directly from my NCE powercab around the layout under the track, terminating wire just before it returns to the power location. from their ran feeders to two locations each on the oval track, and ran feeders on all sides of switches. some areas have power, others don't. not sure why?
i have a link to pictures on the previous posts that have the track layout. as far as polarity, have no reverse loops, and using atlas switch, which i believe are dcc friendly and insulated. red wire for outside of track, black wire for inside of track and just followed that motto.
1. could I have used the wrong solder? when soldering some of the rail joiners to connecting track. would that affect conductivity
2. do I not have enough of the feeder wire on the track rail? for a good electrical connection
3. not using the correct type of wire? using primary wire 18 g stranded for bus and 20g for feeders
is there a specific brand that works best for this application?
looking forward to some good feedback from others with more experience in modeling then me- thanks!
rrinker And the DC guys always laugh at how complex it gets. Keep it simple. No reason to be complex here. --Randy
And the DC guys always laugh at how complex it gets. Keep it simple. No reason to be complex here.
Yeah, that's the thing about DCC. It eliminates the need for block wiring and gapping and then we send the OP off with his 4x8 layout and NCE Power Cab to set up power districts, terminal blocks, rail gaps, feeders everywhere, etc., etc, etc. Makes no sense.
rrinker Unless power shutoffs are wnted, there is no need to gap anything. There are no reverse loops or wyes. Modern Atlas turnouts are all power through, not power routed. In fact, most of mine have feeders on all three legs, seems to make them highly reliable - I attached wires to power the frogs but never ended up connecting any of them because even my smallest loco creeps through without stalling. --Randy
Unless power shutoffs are wnted, there is no need to gap anything. There are no reverse loops or wyes. Modern Atlas turnouts are all power through, not power routed. In fact, most of mine have feeders on all three legs, seems to make them highly reliable - I attached wires to power the frogs but never ended up connecting any of them because even my smallest loco creeps through without stalling.
That pretty much says it all. As Randy said, there is no need to gap anything.
I am surprised that cuyama has not paid a visit to this thread. After all, he designed the track plan.
The advice on this thread makes it appear that the OP is designing a club layout. Terminal blocks, gaps, power districts, whatever. Geez, it is a 4x8 layout with no reversing sections, no power routing turnouts, no live frogs.
A pair of bus wires and feeder wires on every end of every turnout.
That's it.
JRL140,
You may also find this useful, for a go to resource for wiring:
http://www.wiringfordcc.com/track.htm
Frank
Thanks Kyle,
that helps alot, so it seems my main point of contention would be feeding the yard and turnout areas well, the long runs seem to have less feeds, 3 ft. apart, mentioned.
Here is the link to the PDF I was talking about: http://mrr.trains.com/-/media/Files/PDF/trackplans/2012/01/Virginian%20Ry.%20showing%20turnouts%20and%20feeder%20locations.pdf
Randy,
see that you are from Reading, PA, are you going to visit the WGH tour in the Greater Philly area this month?
thanks everyone for the feedback!!! really appreciate the input!
Based on some of the responses, I don't think I want to venture down creating seperate power districts! Not sure if I need to gap anything, I put pictures (off my link) of the atlas turnouts and a picture of conceptually what Randy mentioned about putting power to the three areas around the frog (at least I think) on the turnout to have correct power. It looks like the atlas turnouts have insulated frogs? and the crossing as well is insulated?
I also put another picture of the track plan with what I think is the polarity of each rail throughout the layout and would attach the appropriate feeders accordingly.
Replies seem in agreement, one BUS wire circling the layout can feed the layout, with feeders needed where applicable to create good operation.
I checked out some of the videos and had the magazines for some of the Virginian layout work, since its a 4x8 and they also use the NCE powercab. Popp uses 3M suticase connectors, is that advisable, since I shouldn't have that many feeders as well?
Also, Kyle, don't have an active subscription to the magazine, so can't access the track plan in the database, its a MR extra, you mentioned the plan shows the place he put track feeders along the layout? do you have a copy of it?
http://www.flickr.com/photos/113749345@N07/ pictures
rrinker Unless power shutoffs are wnted, there is no need to gap anything.
Thanks, that makes things easy and will surely put JRL's mind at ease. The advice about feeding them will also serve well.
Mike Lehman
Urbana, IL
The way I view the OP's track plan is quite simple to wire. It is only a 4x8, so break it up into 3 power districts, 1 being his double loop, his industrys in the center and his proposed add on at the top. That looks to me that will be the only places he will need to insulate both rails to accomplish that, with a simple SPDT on off switch to isolate the districts. It will also be much easier to find a trouble spot that way, to find out what is causing the problem. The KISS principle.
Take Care,
Good question. Last time I was up close and persoanl with anything trackwise from Atlas was about 1974. I think it depends on which Atlas turnouts? The #4s just say NOT SnapTrack, while the #6s say CustomLine.
But I think they're both CustomLine? Which says it has a blackened metal frog. Doesn't say anything about gaps, power-routing or the somewhat deceptive "DCC friendly" so my guess is that he will need gaps.
Can some more familiar with Atlas track confirm?
The Atlas HO code 83 Custom-Line turnouts are constructed so that regardless of the switch point setting, both branches are powered. Due to this design, The metal frog is insulated and carries no current.
If you are running a bus wire under the track, then you might as well take a minute or two to run the feeder wires up to that 6 inch section of track than risk having tons of headaches over electrical reliability. If you do decide to add feeders later if you didn't in the first place, you'll have to work around scenery and you have to pull everything back up, and clean up again.
JRL,
BTW, when we say "gaps" this could also include use of an insulated rail joiner, for instance to gap a turnout on the two legs of the frog. You don't really have to cut very many gaps if you work things right, just use the insulated rail joiners judiciously.
mlehmanThe turnout off the main will need gaps in the two rails diverging from the frog. The turnouts in the yard need one between every frog on the left side where the rails diverge, but no gaps are needed in the right side rail.
The track plan indicates that Atlas turnouts will be used. Are these gaps necessary if he uses the Atlas items?
OK, you need to figure out your gaps here. Because gaps define sections of track that need to be fed separately for whatever reason.
The first thing to do is to figure how gaps work around a turnout and why. That way you can choose how to do it to suit your needs, as there is some flexibility here. But you have to avoid mismatched electricity from coming together.
The first example to look at is the stub-end yard at the top. The turnout off the main will need gaps in the two rails diverging from the frog. The turnouts in the yard need one between every frog on the left side where the rails diverge, but no gaps are needed in the right side rail.
If this all makes sense and you can draw a pic to show where you think the gaps are to satisfy yourself, good. or you can post it so we can check what you have diagrammed.
After that, the feeders will be easy. You'll need at least one pair for every section of rail separated by a gap. Depended on how many pieces of track you have and whether you want to solder rail joiners or not (see other comments for discussion on that), you may have more than one set of feeders.
Not all feeders are in pairs, but you need enough so very rail gets access to electricity.
Once we get this gaps and feeders thing for the stub yard, then we can move on to more complex questions. Others are free to jump in with their own suggestions, but I thought it might be a good idea to stay in the shallow end of the pool until we get this gaps thing down cold, as it's something you just found out about and are probably still disgesting it.