I am back into model RR, having gotten out of it for 40+ years. All my locos are blue box Athearn, Stewart and Bowser-type I've collected in the last two years and I have no desire to change over to DCC. My layout is a shelf with 45 ft. of track that runs around the wall. I started to change over from one feeder coming directly from the transformer (yes the trains were sluggish at the opposite end of the layout) to one every three or four feet, hoping to eventually get into block control. So I ran two #12 wires under the 45 ft. of track. I then soldered one feeder pair onto the new wires, just for a test. Now the loco will not move until the throttle gets to 3/4 power. It moves at a slow scale speed and something's wrong if I have to crank it up to max to get the thing to move. Then it stops and the red overload light comes on. Every loco I've got does this, so it isn't a loco problem. I'm using an MRC Tech II 2400 Railmaster as power. I hooked up a spare MRC transformer and that one did the same thing, so it isn't the power. Is it possible to use too large a gauge of wire? That's the only thing I can think of that could be the problem. Getting very frustrated and could use some answers from the community!
I have a feeling you are not telling us something, so let me restate your problem.
All engines do this and two separate power supplies do this. You have only one pair of feeders going to the track from the 12 ga wires.
You have a connection from the power source to each of the 12 ga wires.
There are no reversing loops on your shelf layout.
The 12 ga wires are attached to the layout in such a way where there is nothing cutting through both wires and creating a short.
If there were multiple feeders, I would think you wired one or more pairs backwards. As you state there is only one, inspect the rails for something that is shorting out your track. It is not the gauge of the wire causing this problem.
Henry
COB Potomac & Northern
Shenandoah Valley
There are several things that can cause a short circuit that you are experiencing. When the locos are 'sluggish' will moving the points on any turnout improve the situation? Some turnouts have power routing features that can sometimes create electrical issues. Do any of your turnouts have powered frogs which may have been wired incorrectly to a switch machine motor?
Are there any pieces of rolling stock, anywhere, when this is happening? I'd remove all cars and all locos except the one that is being tested---and then see what happens. It's possible to have a short on one of the trucks in a piece of rolling stock. Heck, I once left a track gauge on the rails and had a dickens of a time finding the short---it was right in front of me but I couldn't see it, like not seeing the trees because of the forest.
Are you sure there are no return loops?
Wayne
Modeling HO Freelance Logging Railroad.
BigDaddyIf there were multiple feeders, I would think you wired one or more pairs backwards.
Sounded like nhe started with one pair of feeders and had voltage drop, but everything ran. Now, there's multiple feeders based on what I understand here, but also the system shuts down.
I suspect one (maybe more) pairs of the new feeders is wired the reverse of what it should be.
Look them over carefully to see if the issue is obvious on visual inspection. If not, then disconnect one pair at a time, check if the issue is OK, then re-connect carefully to the correct bus wire. You'll find which it is was if you work through it systematically.
Mike Lehman
Urbana, IL
Nothing I can really add that hasn't been said already.
When you go for your ultimate diagnosis, have a plan and do it in an orderly fashion.
Remember one stinking strand of wire can cause this so you might not even see it.
Thanks to all of you. When I have more time and a little more patience I'll try some of the things suggested.
mlehman, There's only one feeder at this time. I soldered 18 gauge wire to the rails, fed them through a hole in the plywood and soldered them to the 12 gauge wire under the table. The whole 45 ft. of track is still only powered by this one feeder.
sfcouple, Yeah, I thought of the rolling stock idea. I took every piece off the track and the only thing left was the locomotive. No return loops. It's possible there is a piece of metal (nail, etc.) that I have overlooked that is creating a short. I'll check that out. I'm using Peco and Atlas turnouts.... they all worked before, but I'll look into that too.
BigDaddy: You are correct on all counts. No reversing loops in this layout. The 12 ga. wire was strung by drilling holes in the crossmembers (which are made of wood), and feeding the wire through the holes, so no shorts. All I can think is there must be something bridging the rails to create a short that I'm missing.
CNWmanmlehman, There's only one feeder at this time. I soldered 18 gauge wire to the rails, fed them through a hole in the plywood and soldered them to the 12 gauge wire under the table. The whole 45 ft. of track is still only powered by this one feeder.
OK, then there must be something else going on then OTHER than you simply soldering on some different wires. A small bit of wire, scrap, or other conductor may be causing this. Got no idea where to start, then pick a spot and inspect every inch of the track from there so that you're sure nothing is making a connection between the rails except your loco.
Given:
When wired with a single feeder, the trains ran but bogged down some at the distal end.
Conclusion:
There is nothing wrong with the track, power source, or locomotives.
The only change:
The addition of a 12 gage bus with feeders every 3 or 4 feet. Now trains hardly move.
The only possible problem is there is something wrong with the bus or the drop feeders. Check the security, insulation, and polarity of EVERY connection, beginning at the power supply. It is easy to lose track of which rail is A and which rail is B if they are even a little complex.
Dave
Lackawanna Route of the Phoebe Snow
Dave,
That's what I thought, too, but the OP clarified that it is still just a single pair feeding the whole thing.
Then there is something shorting the rails, likely at the furthest point from the feeders since it doesn;t show as a dead short.
When soldering the feeders to the rails, did you use some sort of heat sink to keep from melting the ties, a Kadee track gauge, or one of those 3 point gauges, for example? Is it still on the track somewhere?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Assuming no obvious short can be detected:
We all approach trouble shooting differently; however, if this was my layout I would first cut every single piece of wire leading to the track---any and all. These wires would then be labeled as they can always be re-connected with butt connectors.
Then wires, with alligaor clamps, would be taken directly from the power pack (with all other wires removed from the power pack) to a nearby piece of track to see if a loco runs normally. If not, then the alligator clamps would be placed at different locations including both the straight and divergent routs of each turnouts.
At this point a volt/amp meter can also be used to check for continuity at various locations, paying particular attention to all the turnouts. If all wires leading to the track have been severed, then there should never be a location where continuity is discovered.
If the track work has not been ballasted then an effort would be made to separate the track at several locations in an effort to narrow the area of difficulty.
Disconnect the feeders and test just the rails, with no locos or cars on, using a multimeter set for the highest ohms setting it will go to - 100K range, or 1Meg if ti has it. Measure across the rails - it should be 0, just like when you hold the probes in the air not touching. If ti overranges, turn down the range until you get a reading. Start in the midpoint of the track, then test at each end. One end it should go down, the other up. On the side it goes down, go to halfway between the middle and end and try it. Keep cutting the area in half, or at least by now you should have narrowed it down a bit to where you can just walk along the track and look for anythign possibly bridging it.
If in step 1, the track shows open circuit, then it's not ont he track but rather in the bus wire somehow. Disconnect it fromt he DCC system (so it's just a pair of #12 wire runnign along under your layout). CHeck the resistence there. It too should be an open circuit, infinite resistance, if there are no shorts. Could be somethign silly - if you drove in any staples in spots to hold the wire up between the holes drilled in the crossbraces, you may have driven one through the wires - I think we've all done that at some point.
The only thing different from when it worked is the bus. The problem MUST be in the bus. Disconnect it and go from there.
Do the 12g buss wires go directly to the TECH II? I would assume so, but I never read it as stated.
Could 12g just be to heavy of wire for a DC current?
Ken G Price My N-Scale Layout
Digitrax Super Empire Builder Radio System. South Valley Texas Railroad. SVTRR
N-Scale out west. 1996-1998 or so! UP, SP, Missouri Pacific, C&NW.
Lake Do the 12g buss wires go directly to the TECH II? I would assume so, but I never read it as stated. Could 12g just be to heavy of wire for a DC current?
I just corresponded with my brother, an aeronautical engineer. His quote:
"12 gauge would not cause such a problem. 12 gauge has far less resistance then say 22 gauge and therefore less voltage drop over the length the wire. Less wire voltage drop, the less need -- not more-- to turn the rheostat up" to operate the locomotives.
sfcouple Lake Do the 12g buss wires go directly to the TECH II? I would assume so, but I never read it as stated. Could 12g just be to heavy of wire for a DC current? I just corresponded with my brother, an aeronautical engineer. His quote: "12 gauge would not cause such a problem. 12 gauge has far less resistance then say 22 gauge and therefore less voltage drop over the length the wire. Less wire voltage drop, the less need -- not more-- to turn the rheostat up" to operate the locomotives. Wayne
Lake
True about the resistance.
So it is the same for DC as AC? Even though the large aircraft use 115 VAC.
DC for small private aircraft.
Lake, yes the 12g buss wires connect directly to the Tech II.
The gage of the wire is not the problem. Either something is miswired or something is fouling the track.
There is no such thing as using "too big of a wire" If it physically fits and you can afford it, it's not too big, from a technical point of view. You can use solid rods of copper 4" in diameter for 'wire' and it will work. The only technical concern is if the wire is too SMALL - #12 is not too small in this case.
Lake I just corresponded with my brother, an aeronautical engineer. His quote: "12 gauge would not cause such a problem. 12 gauge has far less resistance then say 22 gauge and therefore less voltage drop over the length the wire. Less wire voltage drop, the less need -- not more-- to turn the rheostat up" to operate the locomotives. Wayne True about the resistance. So it is the same for DC as AC? Even though the large aircraft use 115 VAC. DC for small private aircraft.
I just corresponded with my brother, an aeronautical engineer. His quote: "12 gauge would not cause such a problem. 12 gauge has far less resistance then say 22 gauge and therefore less voltage drop over the length the wire. Less wire voltage drop, the less need -- not more-- to turn the rheostat up" to operate the locomotives. Wayne
My brother is also an avid Model Railroader in HO, along with a fabulous Garden Railroad. He only addressed the wire gauge issue as it related to the OP's problem using DC. Sorry, but I don't have an answer to your question and wouldn't want to speculate.
We don't know if the buss wire is insulated or bare. Lot's of people use bare, but the opportunity for misadventure exists. I'm still betting on a tool across the rails.
Somewhere you have a heavy load drawing too much current. A short down the line and enough resistance in the rail connections to prevent the power pack from seeing a dead short immediately.
Get a meter and probe from the power pack toward the loco and maybe even without anything on the track. Old fashion trouble shooting.
A few I have known had to cut a rail to isolate parts of the layout.
http://www.trainelectronics.com/Meter_Workshop/index.htm
I have four of these meters for some 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.
I found the problem!!! When I had disconnected all the feeder wires except the one, I had wound the loose feeders into a pigtail so they were not dangling in the way, and on two of them the wires were touching together to short out the whole layout (they are still soldered to the track above). After separating them, the loco ran great! Thanks for all your help, people! I'm back in business. I knew it had to be something simple...
Congrats...thanks for letting us know.