Cornwall,UK
Thanks, beartracks. I am a member of the NCE-DCC forum on Yahoo Groups. As you indicated, there are mixed feelings about continuous loop bus wires, the use of snubbers, etc. I plan to buy a second booster based on the discussion in this thread. That will eliminate my current continuous loop.
Rich
Alton Junction
I recommend you post this question on the NCE forum website or better still do a search of that site because the question has been previously discussed. Not a good idea to join the ends. Also use a terminator wiil help keep the DCC signal clean especially long runs. By the way are you using 14 or 12 AWG wire size for the long runs. If the wire gage (size) is correct for the recommended length then there should be only about a 5% voltage drop.Again see the NCE forum site and Mark Gurries discussion on bus length, terminators, etc.
rrinker Think we already covered this, but you would ideally want to put breakers right after the booster and feed even the main with a breaker section, not feed the main right off the booster and then add a breaker for the yard. That way each area is isolated from the others and an incident in one will have no effect on the others.
Think we already covered this, but you would ideally want to put breakers right after the booster and feed even the main with a breaker section, not feed the main right off the booster and then add a breaker for the yard. That way each area is isolated from the others and an incident in one will have no effect on the others.
Our HOn3 modular spec (Free-mo based) calls for a circuit breaker for each module set. The purpose is to to prevent the entire setup from being shut down by re-railing (most common cause) or a derailment or a short in a given module set. This is important when we have 10+ trains running simultaneously on a large setup at a show.
The effect is to distribute the ciruit breakers around the layout. The circuit breaker attaches to the run-through track bus on each module set. A sub-track bus downstream of the breaker feeds all the track on the module set. At the ends of each module set, we leave the tiny gaps in the rails open. No rail joiners are used, just level and align the rails to the touch of the finger using the legs, then clamp when proper alignment is achieved. Gap masters (sets of PC board ties) are used to keep and solder the rails in place at the module ends.
The only hitch has been when the module circuit breakers, booster circuit breaker, and auto-reversers were not set up properly. We have had to tune the devices so that the auto-reversers trip faster than the module circuit breakers which have to trip faster than the booster circuit breaker.
As a side note I have come to despise auto-reversers, especially when all the reversing sections are wyes or turntables. I just dislike the whole concept of acting on deliberate short circuits during normal operations. Turntables can use split ring wiring, and wyes can easily be wired to switch machine contacts, so that the auto-reverser is unneeded. But that's just my opinion - most of the club disagrees with me.
Fred W
That's Murphy's law #1, they layout will always operate flawlessly - when you're the only one there. Add visitors, and that perfectly straight section of track that you can push a car through at a scale 500MPH with no problems will suddenly cause every single train that passes over it at a proper scale speed to derail.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker However - I really don't know if I actually needed any of this anyway. I only ever ran trains by myself. If you run solo 100% of the time - does it really buy you anything that other sections of the layout keep going when you make a bonehead move in the yard?
However - I really don't know if I actually needed any of this anyway. I only ever ran trains by myself. If you run solo 100% of the time - does it really buy you anything that other sections of the layout keep going when you make a bonehead move in the yard?
For the first 10 years of operating my layout, I have had a single booster and no separate power districts. I never gave any thought to circuit breakers for different parts of the layout. However, every time a loco causes a short anywhere on the layout, every other loco comes to a halt, sounds stop, lights go out. When the power comes back up, most often the sound returns but the lights don't. Locos often need to be restarted. So you need to reset things. No big deal, but not realistic, not prototypical, and it takes time.
Now that my main line tracks are nearly bullet proof, most of my problems occur in the passenger station, coach yard, freight yard, and engine servicing facility. So, it makes sense to isolate those problems without bringing everything else to a halt. That is even more important when guest show up. Did you ever notice that most problems occur when you least want them, that is, when guests are over and just want to see trains run?
Either/or. 60 feet of wire is 60 feet of wire, regardless if it comes before or after the breaker. Now, if BOTH outputs of the breaker are going to control an area 60 feet away from teh booster, it makes more sense to run one long wire to the breaker, then two shorter ones to the controlled sections. But if one is nerby the booster and one is 60 feet away, it makes more sense to keep the breaker close and run one long bus for the distant area.
As for how many breakers and how to break up the layout, that depends more on how you operate than anything. The idea being to keep trains elsewhere running. My layout I'm now taking down is single track, what I did was make the north half one distric, the south half of the main a second, the yard a third, and the staging a fourth. I was probably going to make the cement plant a fifth, since it would have a lot of tracks and turnouts. Going on the ground while switching the yard, no problem. A road train switching the industries on the north end, wouldn;t stop one working the south end, or the yard job.
However - I really don't know if I actually needed any of this anyway. I only ever ran trains by myself. If you run solo 100% of the time - does it really buy you anything that other sections of the layout keep going when you make a bonehead move in the yard? With a room full of operators, all concentrating on their assigned jobs, it's annoying when everything stops. Having a bright red flashing light on the fascia near each breaker section is great for the peer pressure, easy to identify who messed up. Bet after a few embarrassing moments, they remember to check the track ahead and not run through open switches.
Since the issue of circuit breakers has been raised, let me ask a question about the placement of breakers.
My layout is essentially a double main line in a continuous loop with passenger stations, coach yards, freight yards and engine servicing facilties spread through the inside of the loop. The continuous loop can be thought of as an oval, but it is folded, as shown in the earlier diagrams that I posted in this thread.
Currently, my command station and booster are located at one end of the loop. If I add a second booster, it will be at the other end of the loop. My plan is to create four power districts, the north end of the layout, the south end of the layout, a third power district for the passenger station/coach yard, and a fourth power district for the freight yard/ engine servicing facility. Since the passenger station and coach yard are situated at or near the end of the north loop, my plan would be to split the buss wires from the booster into two circuit breakers with one breaker branching in two directions up and down the mainlines and the wiring from the other breaker supporting the passenger station/coach yard.
The issue then becomes where to place the two circuit breakers on the south end of the loop. If I split the buss wires from the booster into two circuit breakers with one breaker branching in two directions up and down the mainlines, the other breaker will be wired to support the freight yard/engine servicing facility. But, the freight yard/engine servicing facility are at least 60 feet away from the booster. So the question is whether that will be a problem running wires from the breaker for a total of 60 feet to reach that power district. Or, should I run 60 feet of buss wire from the booster down to the power district and install the circuit breaker there where it is closer to the power district that it will control. Or does it matter where I position the breaker?
One alternative is to place the booster and the two circuit breakers in the middle of the layout, instead of at the south end of the loop, and keep the two circuit breakers close to that booster. I considered that but, for practical reasons, I want to keep the boosters at the ends of the loops.
Any thoughts?
When I was making reccomendations to the club for the DCC switchover, I recommends the DCC Specialty PSX series. They have a small led on the circuit board to tell you when they trip. But the offer optional buzzer and closed contacts to let you know when they detect a short.
I was about to connect all the PSX boards to NCE AIO boards and have a computer report which districts were occupied and/or shorted for the club. But my freetime to help the club grew shorter and shorter as my two sons came into my life.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
The pros with a continous loop is that you cut the longest path your electricity has to travel in half. It also doubles the amount of wire leading to the same location. This leads to the lowest voltage drop under load.
This isn't an issue if you run from 1 master breaker. But if each end of the loop is on a separate breaker, you could end up running twice the current you were expecting. So I would go Booster->breaker->loop wire connection point.
On really really really long runs, loops can cause the bus (power and command) to get out of sync with phase shifts. Some command stations also use a point to point protocol. So the command gets daisy chained down the line till the end of the line. If there is no end of the line (like in a loop) how will the command know to terminate?
And if you want the ultimate protection, at least with Powershields, set them for manual reset and add a button. That way, when the breaker trips, power is OFF until you fix it. This could get annoying rapdily if there are many small shorts such as the switch frog sort of things where momentum is enough to clear the short by the time the breaker automatically resets. But if the only time anything shorts is if there is a derailment, using the manual reset makes sure the power is off until you fix the problem.
Here is a link to Dick Bronson's discussion that was mentioned by Randy.
http://www.rr-cirkits.com/Notebook/short.html
The tail light bulb solution is certainly less expensive than the circuit breaker alternative, but the circuit breaker alternative seems more foolproof and less fraught with downside risk.
To me, the light bulb solution is sort of like my grandparents sticking a penny in the fuse box.
I just can't bite on the light bulb thing - those are about 2.1 amps, at 15V to the rails that's over 30 watts, still hot enough to melt something. Dick Bronson over at RR-CiKits has a nifty alternative that costs only pennies more, using a dual filament bulb. In the case of a momentary short, like a wheel brushing a turnout frog, or turning the power on with a sound loco with high inrush sitting on the track, it acts just like the regular taillight bulb. Maybe a brief flicker of the bulb, but power still flows. If the short lasts longer, the PTC fuse opens up and the current flows throught he other filament of the bulb only, which is under 1 amp.
My other concern is, will you think of the bulb months after you install them and suddenly one section of the layout is dead? Right now, reading this, you say to yourself, well, it's obvious it has to be a bad light bulb. But when you have a bulb that almost never is lit up, a blown bulb is not the first thing that comes to mind. I think if I used light bulbs across my whole layout, I'd rig up a 'lamp test' switch so that with the flick of a switch, they would all light up so I could easily check them all. It's not trivial to do such a thing though - I'm thinking pretty much one realy for power block, but if you do that, might as well hook one of those PTC fuses to trip the relay and completely cut power in the event of a short - poor man's electronic breaker. Of course now you're getting complicated wnough to just get one of the commercial breakers. Or build your own, I believe there's a circuit for one on Rob Paisley's electronics site.
That's what the $6 tail light bulb is for. It glows when the short affects the area it serves, while the rest of the layout stays afloat.
-Crandell
mlehman I will say on the subject of power districts and circuit breakers, they are a good thing after I was initially skeptical myself. No real need for them with a small outfit that will always be a one man op. But if you run multiple trains or have multiple operators, they are really helpful in avoiding shutdowns in other areas of the layout beyond where a short occurs.
I will say on the subject of power districts and circuit breakers, they are a good thing after I was initially skeptical myself. No real need for them with a small outfit that will always be a one man op. But if you run multiple trains or have multiple operators, they are really helpful in avoiding shutdowns in other areas of the layout beyond where a short occurs.
As a lone wolf operator, I saw no need for separate power districts and circuit breakers. But a recent incident convinced me otherwise.
While running a train on each mainline, I was taking a locomotive on the turntable approach track to the turntable when it derailed on a turnout. It shorted the system and everything came to a halt. If I had my entire engine servicing facility on a separate power district and circuit breaker, the two mainline trains would have continued running, while I rerailed the loco on the TT appproach track.
Richard,
I agree, keep it simple when you can. But Rich's empire is a bit larger than yours, although not the monster you described. I'm pretty sure the booster is worth the investment. He also has more than 50' of bus run, so really can't serve the entire layout from one point.
I actually think he's keeping it pretty simple so far, he just wants to make sure he has his bases covered.
Mike Lehman
Urbana, IL
Cute post. A great example of hyperbole.
As an electronics engineer, I realize all DCC is a series of time ordered pulse trains of rather low frequency and as such there is little to be at issue with all but the most massive layout running tons of trains simultaneously with many remote cabs and power districts.
I have a looped shelf layout with about a 50 foot effective track loop and run a T buss making each buss leg end ~25 feet distant from my single Zephyr extra. I will never run a booster or have any power blocks All that extra stuff is wasted when I plan to never own more than about 5 HOn3 locos, and maybe in a distant future have one and only one remote cab control.
I plan to never run more than 2 locos at a time. The DCC buss remains simple 12 gauge THHN wire separated by about 8" as it runs down the center of the 2 foot shelf. Any short power takeoffs from this main buss are 18 gauge individual wires run to a two lug block right under the track where two bare 24 gauge wires of under1" length are soldered to each and every 3 foot section of flex track.
So far 0.000 issues, anywhere.
If you are planning a massive empire in DCC with five large yards, 900 feet of track total, 12 remote cabs and 30+ engines, you may have issues that can be many and varied and they will have to be solved on a virtual case by case basis. Keep your layout simple and your issues will always be easy to solve. Big roads need and demand boosters, power blocks and cabs.
Brass hats on the big roads have a lot of real world worries, issues and headaches. If you put on the brass hat of a DCC empire expect real world DCC issues.
In closing,.....On any looping DCC layout, run a "T" buss of 12 gauge wire with a wide separation up to 50 feet on each leg of the "T". Branch off this buss with 18 gauge wire where demanded and use only an inch or less of fine solid #24 or even smaller wire to the rails near the middle of each 3 foot section of flex track and you should be free of any real issues. (This advice is for HO and N only!)
This means that no matter where your loco is located on the pike, you are never more than 18" of rail away from a direct, heavy buss connection. Thus, defective, unsoldered or even missing rail joiners will have no effect at all on the electrical operation of your trains.
Richard
If I can't fix it, I can fix it so it can't be fixed
There is great discussion here. No need to repeat.
I vote for Litz wire, tuned snubbers, a dedicated oscilloscope at each end of the buss and perhaps a spectrum analyzer.
Maybe we should place our track inside of a waveguide. Well - subway and tunnel track anyway.
The mind is like a parachute. It works better when it's open. www.stremy.net
Sweet!
Thanks for confirming that Randy. This might solve what I suspect is a common problem for anyone needing to add a booster remote from a command station.
Excellent, thanks, Randy.
RJ-H is 4P4C, same wire used for RJ11, but the plug and jack are physically smaller. So if your crimper will do an RJ-H, you just need a couple of plugs and a long length of 4C flat wire and you can make a cable that plugs from one command bus jack to the other, no extras needed.
mlehman OK, had another idea. I've got one of those fancy crimpers to put various RJ plugs onto cables for telco or ethernet apps. It may be possible to take a handset cord, cut off one end and crimp a standard RJ to it to snap right into the wiring block.
OK, had another idea. I've got one of those fancy crimpers to put various RJ plugs onto cables for telco or ethernet apps. It may be possible to take a handset cord, cut off one end and crimp a standard RJ to it to snap right into the wiring block.
I have been giving this issue some additional thought as well.
I have a crimping tool that will accommodate a large number of connectors.
How is the 4-wire RJ-H constructed?
Is it a flat 4-wire cable with RJH/RJ9/RJ22 connectors, that is, a 4P4C jack?
richhotrain OK, thanks, Randy, I understand the problem. Here is another question. Once I gap the rails and divide the double main line into two separate booster districts, do I have any concerns as a loco crosses the gaps from one booster district to the other booster district? Rich
OK, thanks, Randy, I understand the problem.
Here is another question. Once I gap the rails and divide the double main line into two separate booster districts, do I have any concerns as a loco crosses the gaps from one booster district to the other booster district?
Rich,
So long as you have the command station and booster cases grounded together as previously discussed, no. The command station takes account of anything that may be needed electrically.
rrinker The RJ-H is a handset jack - they are smaller than a regular RJ11/12. It's hard to get long cords with those, normally they are the coiled type. Some crimpers do both sizes, the ones I have do, so if I get the ends I could make such cables. By using the jacks like shown, you can buy one bacis handset cord, cut it in half, and screw the wires to the terminals inside the block, then interconnect the block with an ordinary RJ11 flat wire, which you can easily get in just about any length, even over 100 feet if needed. That may not be what he had in mind, but going the other way - plugging a cable from teh booster to the jack, adn then just running wire between jacks, well, good luck finding a jack like that with a HANDSET socket on it, it's just not used like that and they will be hard if not impossible to find. --Randy
The RJ-H is a handset jack - they are smaller than a regular RJ11/12. It's hard to get long cords with those, normally they are the coiled type. Some crimpers do both sizes, the ones I have do, so if I get the ends I could make such cables. By using the jacks like shown, you can buy one bacis handset cord, cut it in half, and screw the wires to the terminals inside the block, then interconnect the block with an ordinary RJ11 flat wire, which you can easily get in just about any length, even over 100 feet if needed.
That may not be what he had in mind, but going the other way - plugging a cable from teh booster to the jack, adn then just running wire between jacks, well, good luck finding a jack like that with a HANDSET socket on it, it's just not used like that and they will be hard if not impossible to find.
Randy and Rich
Yeah, either way would work, with the main idea being to get from the telco type jacks out of the black boxes to hardwiring for the greater length of the run.
I understand what you mean about the wrong connector on the handset cord, but I thought there was a way to get one that will directly take a handset cord. Maybe scrounged from on old phone is what I think I've seen done. In any case, Rich will have trouble finding a 92' handset cord so we gotta do something, even if it's something not quite as elegant as would be ideal.
Mike, what am I missing here?
Why not just run a 4-wire cable directly between the two boosters?
Are you saying that the connectors are not the right size?
richhotrainWhy not just run the 4-wire telephone/low voltage cable directly into each booster connectionZ?
Because there's only the RJ connector at each end of the circuit. That big honking 22 gauge wire is kinda hard to reliably stuff into that RJ socket.
Essentially, this is the easiest way to do it, close to plug and play. Just so it's clear what I'm talking about here's a pic and link to the correct product at Menards, although $7.99 is way pricey :
http://www.menards.com/main/electrical/wall-plates/phone-cable/ivory-modular-surface-mount-telephone-jack-nylon/p-1403400-c-6478.htm
The cover comes off and the 4 terminals to hook up your 4-wire low voltage/telephone cable are underneath.