I have a large quantity of used telephone wiring left from revisions in the office. Don't know the gauge. Is it suitable for feeding power from the mail bus to track in HO with DCC?
The Digitrax manual for my system says: On an average size layout Digitrax recommends that the power bus from the booster be at least 16AWG. When feeding areas up to 50’ from the booster, using 12 AWG wire for the power bus is recommended. From the main power bus they recommend dropping feeders (22-24AWG)approximately every 6 to 10 feet of track. Sets of feeders should be wired to both rails and they recommend at least 2 sets of feeders per power district. Paul
The Digitrax manual for my system says:
On an average size layout Digitrax recommends that the power bus from the booster be at least 16AWG. When feeding areas up to 50’ from the booster, using 12 AWG wire for the power bus is recommended. From the main power bus they recommend dropping feeders (22-24AWG)approximately every 6 to 10 feet of track. Sets of feeders should be wired to both rails and they recommend at least 2 sets of feeders per power district.
Paul
Perhaps a drop of a few inches from the track to the bus, but I wouldn't. Wire is cheap, why risk it to save a few cents?
On the other hand, I have used telephone wire to run to twin coil switch machines with no problems.
Dave
Lackawanna Route of the Phoebe Snow
Calapooia I have a large quantity of used telephone wiring left from revisions in the office. Don't know the gauge. Is it suitable for feeding power from the mail bus to track in HO with DCC?
Telephone wiring is either 22 or 24 gauge (24 likely); this would work for short feeders from the bus to the track. Mike Polsgrove (writing in the How To Article Good Wiring Practices) suggests 22 gauge wire no longer than 12 inches; over that, using 18 gauge for most of the feed run.
Another good discussion on wiring (and a great intro to DCC) is found in Mark Gurries' NMRA 2011 presentation entitled DCC Layout Wiring which can be downloaded at: http://sites.google.com/site/markgurries/home/nmra-dcc-clinic-pdf-files
Alan
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/
i have no experience with DCC. i understand DCC requires heavier wiring that straight DC.
my layout is rather large but the control panels are usually only serving blocks within ten feet or so of the panel location. i have used telephone wire for all my panel to track wiring with no ill effects or voltage drop. i double the wire for most runs, dropping down to a single wire for the last few inches connecting to the rails.
all blocks have feeders no less that six feet apart and all rail joints are soldered.
my ground is a buss of 10 gauge bare copper wire than runs beneath the entire layout with drops from the common rail to buss made with the telephone wire.
i use heavy (12 gauge) single wire to get power from my power supplies to the control panels and then telephone wire from rotary switches or toggles in the panels to the track..
if you have a non-ferrous metals scrap dealer in your area, check to see if they have any surplus wire in quantity and size you need. these guys often get partial spools of copper wire in as scrap. they will often sell you some for salvage price. they might also purchase your telephone wire if you choose not to use it. insulated wire scrap bring around a buck a pound in my area.
there is a railroad connection to my telephone wire. when the old Big Four freight house on Front St in E St Louis was abandoned after the 1968 merger, they tore the entire phone system out and they gave me an automobile trunk full of wire cable that was in the building. i had miles and miles of the stuff.
charlie
For short drops to the bus, I see no electrical issue.
My main concern when using it is that it's solid wire, not stranded, right? So it'll be a little harder to work with in some cases and more prone to breaking when flexed repeatedly than stranded. In most cases, this won't matter, but if certain places you may want to have some stranded on hand to use instead.
Mike Lehman
Urbana, IL
The voltage does not drop, but the current does.
LION has found (although others deny that this is true) that you sacrifice the SLOWER speeds with the lighter wire. With a big fat wire the train may start moving at 2 or 3 volts, with a thin wire it may take 4 or 5 volts just to get the current out to the locomotive because of the resistance in the wire.
Maybe the LION is all wet, as others have said, but that *is* my two cents.
What KIND of telephone wire? -- LION uses 25 pair cat-3 wire to pre-wire distribution panels around the layout. This works fine for switch machines and signals:
I can record all of my wiring just by recording the pin numbers in a book.
For finer wires, such as in the assembly of signals, the LION has ripped apart any number of old parallel port printer cables. The older spec yielded 25 conductors, while the newer spec has 25 pair of very fine conductors.
LION also uses ribbon wire of the sort used by computer IDE drives for deck plates, rolling doors and corrugated walls.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
BroadwayLion The voltage does not drop, but the current does. ROAR
And then when you are pulling max current, the voltage drops because the wire is too small. The smaller the wire, the more resistance.
22 gauge is the smallest wire that you should use for feeders. It is rated to handle 5 amps for short distances. Smaller wire may work, but not as well as 22 gauge or larger.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
gandydancer19 BroadwayLion: The voltage does not drop, but the current does. ROAR And then when you are pulling max current, the voltage drops because the wire is too small. The smaller the wire, the more resistance. 22 gauge is the smallest wire that you should use for feeders. It is rated to handle 5 amps for short distances. Smaller wire may work, but not as well as 22 gauge or larger.
BroadwayLion: The voltage does not drop, but the current does. ROAR
And the longer the wire, the more resistance it offers. For a short drop, this is one thing, as a feeder from somewhere else it is quite another. LION uses 18ga feeders, but this is only because the LION has lots of short pieces of 18 ga wire.
So, let's look at this wire.
I acquired (with permission) a lot of new-on-the-roll communications wire when a former employer re-did all the communications in a large store. Most of it is #24, in pairs.
Two #24 wires = one #22 wire, so I just use a pair as a single wire between terminals, or between the last terminal and the end user. Since I run analog DC I don't have the signal attenuation problem that seems to drive DCC wiring, but I would say that, for short drops, a twisted pair of any phone wire, used as a single wire, should work.
For low-power applications (Tortoise machines or LEDs) #24 wire is quite adequate.
OTOH, I also have some 30 year old 50-pair cable. Those wires are #22, and are good for anything I need them for except 120VAC and common-ground busses. The latter are #12 solid wire.
Chuck (Modeling Central Japan in September, 1964)
The 24 gauge wire will probably work just fine if:
The test of your wiring is the quarter test. Lay (not press) a quarter across the rails as far away from the feeders as you can get. If the DCC system circuit breaker doesn't pop or interrupt immediately, you have too much resistance in the wiring. Short circuits and/or derailments that don't pop a breaker can fry things. If there is too much resistance, you need either heavier wire and/or more closely spaced feeders. There should not be a place on the layout that does not pass the quarter test.
You can get away with lighter gauge wire and still pass the quarter test if you have a small DCC system (2-3 amps).
Personally, I use 24 gauge magnet wire for feeders at home. But I use DC at home (less than 1 amp), and I feed every piece of rail where I have handlaid track.
I plan to use the same feeder system on the my DCC Free-mo (HOn3) modules. These will have to be tested to make sure it works. We require every module to have its own breaker for problem isolation reasons. Since my under-construction modules are single track with no passing siding, double or triple headed sound-equipped engines with a few lighted passenger cars are the worst-case loads. I can set my breaker to 2 or 3 (worst case) amps, and make sure I meet the quarter test everywhere on the module.
my thoughts, your choices
Fred W
Wire that small has its uses: it can be used to electrically connect two pieces of flex track, when you do not want to rely entirely on rail joiners yet may want to allow the gap for expansion and contraction purposes.
I have also used it for modeling purposes as piping -- if stretched it can be made to be quite straight. Sometimes I remove the plastic insulation and sometimes I don't.
Dave Nelson
Voltage absolutely does drop over length of a given wire gauge, and not current. The decoders and short circuit protectors rely on strong voltage, not strong current, for a sufficiently high signal to noise ratio. Current does not provide a medium for the digital signals, only voltage does. You do not get a cleaner DCC signal when your new DCC system offers more amperage throughput, amperage and current being interchangeable terms for our purposes here.
So, as the engineers who designed our DCC systems have repeatedly warned us, do not allow the voltage (they did NOT say 'current') to drop appreciably or your short circuit detection will not work, and your decoders will not be able to meter the correct/intended voltage to the can motors. What causes voltage drop? Poor conductivity. What causes poor conductivity? Poor material choices, increasing lengths, smaller cross sections, smaller conductive surface areas, and finally small contact areas between contact points such as at poorly fitting joiners.
As to the claim above that low voltage drops the slow speed and not the high speed, there may be some truth to that. Voltage is like grease in electric wires. It allows the current to flow efficiently and helps the motors to run cooler at a given current draw (amperage). As you drop the voltage (and I assure you it absolutely does drop, as any credible wiring chart clearly shows), the current gets more resistance to its purpose of allowing the motor to perform more work. So, drop the voltage enough and you end up with maybe two volts and essentially insufficient transmissible amps. That = a stalled motor. Dial up the max voltage on your system and you will probably get most of all the amps the motor needs to make the train move as quickly as you wish.
Crandell
My second 4x8 layout was built when I worked for the phone company (17 years ago). I saw extra wire (single pair, copper, 22ga I think) and got approval to take it. I used this to wire my layout; I was running DC at the time. Every piece of rail had a feeder soldered to it, all frogs powered with micro switches. I knew it wasn't the right wire to use but had no problems with this small wire (no speed difference, sometimes I'd run BB locos (Athearn Blue Box, not the wheel arrangement) and even double headed a few times, just to do it. I got an NCE DCC 5 amp system and disconnected the leads to my power pack and wired it to the DCC booster/command station. It worked fine too; passed the quarter test everywhere. I've run 3 sound locos at a time - 2 on the main and one switching the mine. Doing this by myself was a bit of a ballet to avoid collisions.lol No problems.
I'm not saying you should do it this way, but if done correctly, even the wrong way will work; but its still wrong. I'm no electrical engineer (but I was an A student) so when these DCC companies recommend a certain size wire, I assume it's because someone with far greater knowledge thought about it, did calculations and chose a particular size wire based on numbers, not on what was available, or on sale, or found in a friend's basement.
My current layout uses 12ga for the buss, 18ga for feeders (a bit big but I'm going to run with a Free-mo group and figured I'd be safe rather than sorry; I don't want my modules be the weak link), and every rail gets a feeder soldered to it.
Do things right the first time and you will not be disappointed later on. Maybe a few years from now, there will be bigger motors (drawing more current), or you might want to expand your layout, or any other reason we can't think of now, you might find some (or all) your wiring needs to be replaced...now it's a big job!
Yes you can cut corners, yes you can squeeze things in, yes, you can do whatever you want because it's your layout, but the laws of physics are the same for everyone. Just follow instructions, recommendations and what others have proven to work...period. Why tempt the gremlins that follow us around? We (model railroaders) want as many people in this hobby as possible, and we want you to stick around for many years. Bite the bullet, buy quality everything (building materials, rolling stock, locos, electronics, etc...) and you will enjoy this hobby more than someone who got a bunch of 1970's locos, brass track, cheap rolling stock for free and is struggling keeping track clean, cars on the track, and that loco (with 4 wheel power pickup and 4 wheels powered) going around and around in a loop. It might seem a little expensive at first, but it's TOTALLY worth it in the long haul!
http://delray1967.shutterfly.com/pictures/5
SEMI Free-Mo@groups.io
Gents.....
I can't think of why one or another wire would be better or worse for DC or DCC. Twenty two gauge wire is probably as small as you might want to go. When wiring your railroad don't be afraid to put in redundant risers every so many feet of through track.
With DC we have large old open frame motors and locos going back to the 40's and 50's that weighed a pound and the motors stalled at 7-8 or 9 amps. This conversation seems to be going in a DCC direction so I'll venture off to there now.....
With DCC we are almost required to use can motors or low amp VERY efficient open frame motors and most HO and N scale locos are well under an amp when stalled. That is due to the demand of the decocers. Most can sustain a spike to two amps but really only like extended demand under 1.2 amps. Most Sagami and similar motors run at about .3 of an amp.
Where this is going is............ we are not demanding the current flow (amps) that we used to so we can use smaller riser wires. Yes risers should be less than 12 inches an bus wires of ten or twelve gauge (preferably stranded) wire.
The advent of sound brought a greater current demand for a total railroad, especially if you have a number of Diesel locos idling in a yard plus a few out operating.............. BUT.......... they are probably on different riser wires so current drops are not an issue.
If you are using a big fleet of sound equipped locos a larger hazard is your DCC power source not great enough to handle the demand. Consult you DCC manuals for your total available amps. The magic number for any supply vs. demand availability is to not exceed in continuous operations five eights of total rating. That means that your demand should be at or less than five eights of the source.
see ya
Bob
I too salvaged a bunch of telephone cables years ago and use this wire for all sorts of projects. I have never had a problem with overloading this wire or even experienced any voltage or current drop. I currently use it for all of my feeders between the rails and a 14 gauge buss. Keep in mind that even if this little feeder wire is the only way a section of rail gets power, the train will only run along this length of rail for a short time. In the meantime, there are four lengths of 30 gauge wire connecting your decoder to the rails and to your loco's motor and they have to carry all of the voltage and current necessary for the entire time the loco is running. If those little tiny wires can provide an amp of power to the motor for extended periods pulling a long train, a 24 or 22 gauge wire should have no problem at all, even if two or three locos are running over a length of rail at the same time.
Hornblower
selector Voltage absolutely does drop over length of a given wire gauge, and not current. The decoders and short circuit protectors rely on strong voltage, not strong current, for a sufficiently high signal to noise ratio. Current does not provide a medium for the digital signals, only voltage does. You do not get a cleaner DCC signal when your new DCC system offers more amperage throughput, amperage and current being interchangeable terms for our purposes here. So, as the engineers who designed our DCC systems have repeatedly warned us, do not allow the voltage (they did NOT say 'current') to drop appreciably or your short circuit detection will not work, and your decoders will not be able to meter the correct/intended voltage to the can motors. What causes voltage drop? Poor conductivity. What causes poor conductivity? Poor material choices, increasing lengths, smaller cross sections, smaller conductive surface areas, and finally small contact areas between contact points such as at poorly fitting joiners. As to the claim above that low voltage drops the slow speed and not the high speed, there may be some truth to that. Voltage is like grease in electric wires. It allows the current to flow efficiently and helps the motors to run cooler at a given current draw (amperage). As you drop the voltage (and I assure you it absolutely does drop, as any credible wiring chart clearly shows), the current gets more resistance to its purpose of allowing the motor to perform more work. So, drop the voltage enough and you end up with maybe two volts and essentially insufficient transmissible amps. That = a stalled motor. Dial up the max voltage on your system and you will probably get most of all the amps the motor needs to make the train move as quickly as you wish. Crandell
Well, you're not actually dropping the voltage. As the length of the wire increases, resistance increases, which causes a drop in voltage. That's why I used 12 gauge wire for my busses (DC), and 22 gauge for my feeders. And, my feeders are just long enough to give me 6" of slack under the layout. At my control panel, I used 22 gauge wire from the switches to distribution blocks, which then go out to the track as my busses.
Marlon
See pictures of the Clinton-Golden Valley RR