Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Wiring tortoises, what AWG size do you use?

9827 views
35 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2003
  • From: Finger Lakes
  • 561 posts
Posted by TBat55 on Saturday, August 20, 2005 8:36 AM
The use of heavy gauge bus wire for DCC is to overcome the resistance of nickel silver rail. The longer the piece of rail between feeders, the more resistance and losses (voltage and data).

Now, to route power from either rail to the frog using a Tortoise is a very short distance. Not much resistance. Current is negligible ("flea power").

I use Romex 12 or 14 gauge for bus (~20'), something like 20 gauge for feeders (~1'), and solid 24-28ga for Tortoise power routing. In some case I've used the very small black wire with rail joiners attached (Atlas terminal joiners?) for feeders and/or power routing. No noticeable problems.

I suggest you thing more about soldering the X's to your DPDT switches. Use shrink tubing to prevent shorts.

Terry

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Saturday, August 20, 2005 5:17 AM
I use DPDT switches with all of my Tortoises. They work fine. I do not use the ones with Center Off feature. Just flip the switch and all works quite well.

Alton Junction

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, August 19, 2005 2:23 PM
QUOTE: Originally posted by grayfox1119

Good idea on the rolls of wire by Rex and Randy. I am about to buy some wire, and after your experience Randy, 500 foot roll will NOT be too much will it!!!



Nope, I bought a 500 foot rooll of red #12, a 500 foot roll of white #12, and a 500 foot roll of the red and white #20.

Used about half of it so far on the 8x12 part. Wait til I start building around the rest of my walls..

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2004
  • From: Finger Lakes
  • 10,198 posts
Posted by howmus on Friday, August 19, 2005 1:51 PM
QUOTE: Originally posted by grayfox1119

...most people use #12 gauge wire for the power bus for the tracks, # 14 gauge for the track feeders from the power bus.


Wow! #14 for track feeders? You must be using code 400 track.... (Stops and ponders....) I use #16 for a sub bus network off of the main bus, then use very short runs (less than 1', most under 6") of, 20 or 24 to the tracks. See Alan Gartner's website for suggested size wires in DCC. http://www.wiringfordcc.com/track_2.htm He recommends #14 as the largest for G Scale. For HO the largest recommended is #20 and for N #22. Maybe you were talking about the sub bus running from your main bus and I missunderstood what you were refering to?????

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

  • Member since
    August 2003
  • From: Cherry Valley, Ma
  • 3,674 posts
Posted by grayfox1119 on Friday, August 19, 2005 1:02 PM
Good idea on the rolls of wire by Rex and Randy. I am about to buy some wire, and after your experience Randy, 500 foot roll will NOT be too much will it!!!
Dick If you do what you always did, you'll get what you always got!! Learn from the mistakes of others, trust me........you can't live long enough to make all the mistakes yourself, I tried !! Picture album at :http://www.railimages.com/gallery/dickjubinville Picture album at:http://community.webshots.com/user/dickj19 local weather www.weatherlink.com/user/grayfox1119
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, August 19, 2005 12:26 PM
Right. although you need to double your answer - a 50 foot run has 100 feet of wire in it. But this is why #12 is recommended. Repeat the calculation for #18 wire. A lot of people say "but I used #18 with my DC power pack, why won't it work for DCC"

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    August 2003
  • From: Cherry Valley, Ma
  • 3,674 posts
Posted by grayfox1119 on Friday, August 19, 2005 12:23 PM
Here is the data for #12 copper wire: The resistance of this wire is 1.62 ohms per 1000 feet. By doing a quick ratio and proportion calculation, the resistance for 50 feet would be 0.081 ohms. So if your layout had 2 amps being drawn, this would give you a voltage drop caused by the bus wire alone, of .081 X 2A = 0.162Volts dc. Hardly enough to be noticable. But, there may be other factors contributing to lower voltage at the locos. You must take into account all the voltage drops at all the various connections off the power bus, even the soldered connections have resistance. And, what can appear to be a good solder connection can in fact have added resistance. If you want to check this out without actually using locomotives, place a resistive load across the tracks out at about 50 feet from the power source, and check your voltage drop. If you had a perfect bus with no wire resistance, and no solder/t connection resistance, you would only have the voltage drop across the load resistor. We all know that this is not the case however, so what we do read for a drop is the sum of the all voltage drops caused by all the little resistances along the route ( circuit ).
BTW, some real good ideas here in this thread for wiring and connections.
Dick If you do what you always did, you'll get what you always got!! Learn from the mistakes of others, trust me........you can't live long enough to make all the mistakes yourself, I tried !! Picture album at :http://www.railimages.com/gallery/dickjubinville Picture album at:http://community.webshots.com/user/dickj19 local weather www.weatherlink.com/user/grayfox1119
  • Member since
    January 2005
  • 180 posts
Posted by tsasala on Friday, August 19, 2005 11:18 AM
Good point Rex. Since all my turnouts are relatively easily accessible, I didn't bother with a connector at the turnout. I do have connectors at the control panel though.

-T
  • Member since
    July 2004
  • From: Southeast U.S.A.
  • 851 posts
Posted by rexhea on Friday, August 19, 2005 1:32 AM
QUOTE: Originally posted by tsasala

........... I will concede you don't need twisted pair, foil insulated conductors for switch machines, but if it's near the same price overall, why not? The question to ask yourself is, will you need all 8 wires, or only two? There is a break even point around 4 conductors.

Personnally, I don't think it matters if the terminal block is at the switch or the control station. However, I would not spend the extra money and terminate at both ends. With all things factored in, an ethernet-like wiring setup for the switch machines will be about the same cost, just as flexible, and take up less space. Those terminal blocks are expensive for what you get.

-Tom


Tom, all my mainline tortoise are wired back to Lenz stationary decoders. The reason I chose to use multi-pair cable for my turnout runs, is that I have a large layout and by having spare pairs in place all over the layout gives me the capability to connect future signals, controls, or accessories without having to run new wires/cables. i.e. only short runs of wire from device to spare cable pair. The kind of cable is up to the individual in what he has on hand or prefers to use. Telephone is adequate for the job, but if a person wants individually shielded pairs with ground or fiber optics...what ever works for him.

Over forty years experience in the electronic/electrical fields has taught me never to design or install devices using hard wiring. Plugs , terminal strips, or other intermediate methods of connection is always recommended so that there is an easy disconnect for maintenance or modification. Thus, I use terminal strips at both ends. Some buy the plugs that simply insert on the tortoise connector. Both are good methods.

If you don't think you will ever need to remove the tortoise or other types of devices, then hardwire them in. I have chosen my way because I know that tomorrow will bring new ideas that usually means more bells and whistles to install. (no pun intended [:D] )

REX
Rex "Blue Creek & Warrior Railways" http://www.railimages.com/gallery/rexheacock
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, August 18, 2005 11:28 PM
Those current ratings are for 115VAC too. The main issue with using big wire for DCC is voltage drop, not absolute current carrying capacity. There are charts with the loss in ohms per foot of various wire sizes. The voltage drop is a product of the wire resistence per foot, the length of the wire, and the current being drawn - ie over the same length of wire, running a doubleheader with each loco drawing 1 amp will have 2x the votage drop as the same wire but only a single 1 amp loco running. Now, we're usually talking about a volt or less, with typical run lengths and typical wire sizes. But if you have a run 50' from a booster to a power district and don't use #12 wire, and run more than a couple of locos in that power district, it WILL be enough of a drop to make the trains run noticeably slower.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    August 2003
  • From: Cherry Valley, Ma
  • 3,674 posts
Posted by grayfox1119 on Thursday, August 18, 2005 9:05 PM
To answer your question regarding size of wire vs current carrying capability, most people use #12 gauge wire for the power bus for the tracks, # 14 gauge for the track feeders from the power bus. #12 gauge wire is rated to carry 20amps, while #14 is rated for 15amps. This is de-rated somewhat, as they are capable of carrying a little more, but all homes are breakered at 20 amps for #12 and 15 amps for #14 wire.
Now for switch motors, all you need to do is look at the specs that come with the motors, they will have the current draw/rating on them. They use "flea" power as we say in the electrical business, only milli-amps (ma) of current. #18 gauge wire can carry 10 amps, which is 10,000 milliamps ( ma). So as you can see, #18 gauge wire is gross overkill. #24 gauge will work just fine.
Dick If you do what you always did, you'll get what you always got!! Learn from the mistakes of others, trust me........you can't live long enough to make all the mistakes yourself, I tried !! Picture album at :http://www.railimages.com/gallery/dickjubinville Picture album at:http://community.webshots.com/user/dickj19 local weather www.weatherlink.com/user/grayfox1119
  • Member since
    January 2005
  • 180 posts
Posted by tsasala on Thursday, August 18, 2005 8:25 PM
I also bought the HD spool. For the money, you can't beat it. However, since Cat-5 is so popular, per linear foot, it's cheaper than 2 conductor thermostate wire (2 conductor @ $28/500 feet = 0.028/ft/conductor, 8 conductor @ $78/1000 ft = 0.00975/ft/conductor ).

I will concede you don't need twisted pair, foil insulated conductors for switch machines, but if it's near the same price overall, why not? The question to ask yourself is, will you need all 8 wires, or only two? There is a break even point around 4 conductors.

Personnally, I don't think it matters if the terminal block is at the switch or the control station. However, I would not spend the extra money and terminate at both ends. With all things factored in, an ethernet-like wiring setup for the switch machines will be about the same cost, just as flexible, and take up less space. Those terminal blocks are expensive for what you get.

-Tom
  • Member since
    December 2004
  • From: Finger Lakes
  • 10,198 posts
Posted by howmus on Thursday, August 18, 2005 7:29 PM
QUOTE: Originally posted by rrinker

I use #20 wire for my feeders - #20 solid DOES fit through the Tortoise hole. #18 I think would be too big.
--Randy


You got my curiosity up so I just went downstairs to check. #18 will not go through the little holes. I used #24 and have no problems powering the frogs with DCC.

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, August 18, 2005 7:23 PM
QUOTE: Originally posted by johncolley

I bought a spool of #20 red and white thermostat wire (almost a lifetime supply) and use it for all my track drops and also power my tortoise machines with 2-terminal blocks. Hint: for crossovers and runarounds, etc. I connect both machines to the same terminal block and use one control for both. No chance of a mishap!


You THINK it's a lifetime supply - sounds like you bought one of the same 500' spools at Home Depot that I did. All I've reall done is make track feeders out of it,and run one line from my converted PC power supply around half the benchwork to feed my one control panel. And I'm at LEAST halfway through the spool - on a 8x12 layout!

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, August 18, 2005 7:21 PM
QUOTE: Originally posted by rtesta

Folks, gotta jump in and ask,,,, if i'm going to use my tortoise to switch DCC power on a turnout..

1. do i need to use 18AWG or larger to the machine, if so will i be able to solder wire this big on the connectors on the machine? assume i shouldnt use 24AWG or such here?

2. ive asked in the past, apparently the tortoise internal switches can handle the amps? agree?

i realize i cannot use a 4pdt switch at the control pannel as the tortoise takes time to move, i assume i'd have a short every time, right?

thanks, bt


I use #20 wire for my feeders - #20 solid DOES fit through the Tortoise hole. #18 I think would be too big. However, using #20 isn;t a problem, we're talking short distances here, and if you are switching the frog, there can never be more than one loco on the frog at a given time. If you are talkign about switching an entire reverse loop, I would run a short length of #20 fromt he Tortoise to a terminal strip nearby, and then use heavier wire for the track feed. A reverse loop should have multiple feeders, the same 3-6 feet as recommended for other track.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2002
  • From: Pittsburgh, PA
  • 1,261 posts
Posted by emdgp92 on Thursday, August 18, 2005 1:26 PM
I used 20 gauge wire, as that's what I had on hand. I soldered it to edge connectors. I don't remember who made the connectors, but they work great. I ran the panel lights (a pair of LEDs from Radio Shack off the main power wires. That way, the lights change position when I flip the switch :)

Oh... I should add that my Tortoise machines have their own power supply. I took one of Bachmann's train-set power packs and bolted it to my benchwork.
  • Member since
    July 2004
  • From: Southeast U.S.A.
  • 851 posts
Posted by rexhea on Thursday, August 18, 2005 1:15 PM
QUOTE: Originally posted by rtesta

Folks, gotta jump in and ask,,,, if i'm going to use my tortoise to switch DCC power on a turnout..

1. do i need to use 18AWG or larger to the machine, if so will i be able to solder wire this big on the connectors on the machine? assume i shouldnt use 24AWG or such here?

2. ive asked in the past, apparently the tortoise internal switches can handle the amps? agree?

i realize i cannot use a 4pdt switch at the control pannel as the tortoise takes time to move, i assume i'd have a short every time, right?

thanks, bt


rtesta,
Routing power on a turnout or powering a frog is the same current/power that you would have going through a track feeder wire. I believe many of us would agree that 22-24 gauge wire is plenty big for both uses.

The aux. contacts on a tortoise can handle 4 amps of current. You will not have a problem powering frogs, signals, and etc.. The "switching rating" at 1 amp that is given in the Tortoise directions only refers to continuous opening and closing like a flashing lamp.

I am not sure I understand your question about a 4pdt switch, but the Tortoise aux. contacts will do the job for power routing.

REX
Rex "Blue Creek & Warrior Railways" http://www.railimages.com/gallery/rexheacock
  • Member since
    February 2002
  • From: PtTownsendWA
  • 1,445 posts
Posted by johncolley on Thursday, August 18, 2005 12:53 PM
I bought a spool of #20 red and white thermostat wire (almost a lifetime supply) and use it for all my track drops and also power my tortoise machines with 2-terminal blocks. Hint: for crossovers and runarounds, etc. I connect both machines to the same terminal block and use one control for both. No chance of a mishap!
jc5729
  • Member since
    July 2004
  • From: Southeast U.S.A.
  • 851 posts
Posted by rexhea on Thursday, August 18, 2005 12:41 PM
1. If you have Cat 5 cable on hand or can get it free, then fine. Otherwise, you will be paying a lot of extra money for something you don't need. Cat 5 is designed to prevent "cross-talk" between pairs in high speed data communications...something you don't need to use and pay for.

2. Ordinary telephone cable, that is mostly 24 gauge solid conductor, is all you need to handle the very small current that a tortoise uses and it is a lot cheaper. Some telephone installers will give you hundreds of feet for nothing. Just smile.

3. The wiring advantage to using terminal strips is that you can easily disconnect and change out wiring locations without having to remove components. In other words: You want to change switch 5 to switch number 8. All you have to do is move the wires on the terminal strip and not the switch or component.

4. I like to hard wire (solder) my tortoise with a 12" piece of cable and terminate the other end to a terminal strip, very much like HOWMUS picture. Then I run a main cable back to a central location and terminate the other end to another terminal strip. There I can connect to a decoder, toggle, push-button, or whatever.

5. Again, I recommend not cutting off unused wires. These can be used for future expansion keeping you from having to run more wires/cable.

6. If you are controlling locally, I still recommend the terminal strip between the tortoise and the local control component.

REX
Rex "Blue Creek & Warrior Railways" http://www.railimages.com/gallery/rexheacock
  • Member since
    November 2004
  • 38 posts
Posted by rtesta on Thursday, August 18, 2005 12:06 PM
Folks, gotta jump in and ask,,,, if i'm going to use my tortoise to switch DCC power on a turnout..

1. do i need to use 18AWG or larger to the machine, if so will i be able to solder wire this big on the connectors on the machine? assume i shouldnt use 24AWG or such here?

2. ive asked in the past, apparently the tortoise internal switches can handle the amps? agree?

i realize i cannot use a 4pdt switch at the control pannel as the tortoise takes time to move, i assume i'd have a short every time, right?

thanks, bt
  • Member since
    February 2005
  • From: Sweden
  • 2,082 posts
Posted by electrolove on Thursday, August 18, 2005 11:28 AM
To use a cat-5 cable sounds like an terrific idea, thanks. What are the pros and cons by putting the terminal blocks near the switch or control panel? The first thing I'm thinking of is future use of the middle 6 connectors on the tortoise. Can I run into trouble if I place the terminal block at the wrong location?

QUOTE: Originally posted by tsasala

I'd recommend cat-5 networking cable. 8 conductors and you can use easy-to-find connectors throughout your layout. I, however, did not follow my own advice. I recommend soldering the wires to the switch machine and use connectors or terminal blocks near the control panel (not the switch) However, you can put the connectors near the switch. It's your call.

-Tom
Rio Grande Zephyr 5771 from Denver, Colorado to Salt Lake City, Utah "Thru the Rockies"
  • Member since
    January 2005
  • 180 posts
Posted by tsasala on Thursday, August 18, 2005 11:00 AM
I'd recommend cat-5 networking cable. 8 conductors and you can use easy-to-find connectors throughout your layout. I, however, did not follow my own advice. I recommend soldering the wires to the switch machine and use connectors or terminal blocks near the control panel (not the switch) However, you can put the connectors near the switch. It's your call.

-Tom
  • Member since
    December 2004
  • From: Finger Lakes
  • 10,198 posts
Posted by howmus on Wednesday, August 17, 2005 2:52 PM
QUOTE: Originally posted by CP5170

I used 8-wire telephone wire. I soldered the wire to the Tortoise terminal and then ran the wires to an 8 post terminal strip. I am currently only using the outer contacts but when I am ready to connect to the other contacts, I do not have to disturb the switch machine.

HTH...Ken


Kinda like this?

Ray Seneca Lake, Ontario, and Western R.R. (S.L.O.&W.) in HO

We'll get there sooner or later! 

  • Member since
    July 2004
  • From: Southeast U.S.A.
  • 851 posts
Posted by rexhea on Wednesday, August 17, 2005 2:08 PM
QUOTE: Originally posted by CP5170

I used 8-wire telephone wire. I soldered the wire to the Tortoise terminal and then ran the wires to an 8 post terminal strip. I am currently only using the outer contacts but when I am ready to connect to the other contacts, I do not have to disturb the switch machine.

There was an article in Working on the Railroad by Lionel Stang a few years back. That is where i got the idea.

HTH...Ken


[#ditto]
I also terminate all tortoise points to a terminal strip. To add: I always run a multiple pair cable of 4 pair to this terminal strip from my stationary decoders that are located in a central part of the layout. If the cable is not true telephone cable colors (blue, orange, green, brown, slate, w/white tracer wire) then figure out a color code for terminal 1, then 2, then etc... Stay with this code throughout your layout and it will save on mistakes.

I only hook up those necessary for operating the Tortoise, but I never cut the spare pairs off. Instead, I wrap them around the cable for future use. I use stationary decoders in a central location. If I want to hook up a light in that area, I just pick a pair to connect it to and terminate the other end to the power or control source at the central point. Saves running more wire.[;)]

REX

Rex "Blue Creek & Warrior Railways" http://www.railimages.com/gallery/rexheacock
  • Member since
    October 2009
  • 129 posts
Posted by CP5170 on Wednesday, August 17, 2005 1:24 PM
I used 8-wire telephone wire. I soldered the wire to the Tortoise terminal and then ran the wires to an 8 post terminal strip. I am currently only using the outer contacts but when I am ready to connect to the other contacts, I do not have to disturb the switch machine.

There was an article in Working on the Railroad by Lionel Stang a few years back. That is where i got the idea.

HTH...Ken
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, August 17, 2005 10:58 AM
You might use #18 from the power supply to the control panel, but from each toggle out to the Tortoise, yeah, WAY overkill. #18 will never fit in the hole on the Tortoise.

I'm kind of digging those Tortoise with screw terminals that Empire Northern sells. $2 more but you get 8 easy screw terminals. The stock holes on the Tortoise are staggered for some odd reason, so I assume new holes must be drilled to line up the terminals. Seems more reliable than using an edge card connector, too.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Wednesday, August 17, 2005 10:28 AM
Yes, and you may not even get it into the Tortoise. EL, if you have an electronics supply store, even a hardware store nearby, you should be able to pick up rolls of 22 guage wire. Even better, if you knew someone who wires houses for telephones, he/she would slip you a big fat wad of it.
  • Member since
    February 2005
  • From: Sweden
  • 2,082 posts
Posted by electrolove on Wednesday, August 17, 2005 9:13 AM
So I can't really compare a tortoise with for example a track power bus when it comes to how much it draws? So a AWG 12 or even a AWG 18 is major overkill?

QUOTE: Originally posted by rrinker

SMALL. I have tons of leftover 8-conductor network cable, so I just use that. I don't need the contacts run back to the panel, so I just zip off the outer insulation (there's a tracer string to do this) and use the individual pairs. It's run wire, not patch cable wire, so it's solid conductor, 24-26 gauge. Telephone wire would work just fine.
A Tortoise only draws a max of about 15ma, so just about ANY wire will work.

--Randy
Rio Grande Zephyr 5771 from Denver, Colorado to Salt Lake City, Utah "Thru the Rockies"
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, August 17, 2005 8:47 AM
SMALL. I have tons of leftover 8-conductor network cable, so I just use that. I don't need the contacts run back to the panel, so I just zip off the outer insulation (there's a tracer string to do this) and use the individual pairs. It's run wire, not patch cable wire, so it's solid conductor, 24-26 gauge. Telephone wire would work just fine.
A Tortoise only draws a max of about 15ma, so just about ANY wire will work.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!