Wire Gauge

22 and 24 are way too small for track power. You should be using at least 18 and 16 would be better. Your bus wires could go up to 14. I use 12, but I have long distance runs. Your wire size should be matched to your circuit protection in Amps. I know the values for 12 and 14 are 20 Amps and 15 Amps respectively, because those are used in house wiring. There is a table that has all the Ampacity values for the various gauges. You can never go wrong by over sizing. You can cause a fire by under sizing.

When I build 8x4 layouts for grandkids, I use 16 gauge for track power.  On my own layout, about 38x16, nothing less than 14 gauge. 

Issue is that voltage drop on too-thin wires has substantial adverse effect when loads increase.

Hi all, 

Below is a link to a good voltage drop calculator. 

Think about layout wiring just the same as you would your house. Always make sure it’s absolutely safe. There is no such thing as “Good enough” it is either right or it’s wrong.

i do not want to sound like a know it all or that I am preaching. I have over 30 years of electrical experience. I am licensed and have taught the topic extensively.  I unfortunately have seen to many fires and injury caused by “Good Enough”

22 gauge wire is what comes with most sets, it is only intended to be used in very short runs, less than a foot. Anything over and you risk overheating . In all honesty it should only be an option for a very small temporary set up like a small oval or circle.

To figure out the minimum size bus wire you need to first figure what the load on the wire will be .  

 Next figure out what type of wire you will use. I do not mean gauge,  I mean insulation type or cord type.

once you have the above you can get look at a wire chart and find the right size wire for that insulation type. Then plug the numbers into the calculator below. 

Because we may have a situation with varying voltage go towards the middle of the road with the voltage choice. IE if you will run between 6 and 12 Volts use 9 . 

Last but not least make sure your power supply is large enough. To do that,  multiply your voltage x you current

IE 6 volts x 8 amps =48 watts. You may see watts also called volt amps or  VA. 

Then take you wattage and devide it by .8 this gives you a minimum power supply that is rated large enough to handle the load.

you can use any power supply that suits your needs as long as it is larger than the minimum.

use good wiring practice, make sure you have your wire supported, layer out neatly and joints are made securely. Twisting the wires together and then taping them is never a good choice. 

Voltage drop calculator

John Patrick posted:

Just getting back into setting up my old Lionel Train.  It has been many years. After our move I finally have space to set it up. I have been watching the videos for wiring the layout. I see that Lionel talks about using 16 gauge braided wire for the bus line for both hot and ground to the track. I plan to use the Lionel power wire 6-12053 as the feeder to the track. In looking at the literature I cannot find what gauge that power wire is. Someone told me it may be 22 to 24 gauge. Is there any problem in attaching a 22 to 24 gauge power wire to the 16 gauge bus? Also since I will have some 16 gauge wire left over from the bus I was planning on using that 16 gauge wire as a bus for my accessories. Lionel also talks about using telephone wire for the switches in that they use very little amps. Again is there any problem to using the phone wire red hot wire to the 16 gauge accessory bus?

The Lionel wire is too small of a gauge - it is only 18awg You can get the terminals to crimp onto the wire to make connectors for FasTrack.

Here for non-insulated and here for insulated  The crimp is different for non-insulated, some tools do not have it.

The easiest wire to get in one cable today is called thermostat wire - the telephone wire of today is computer Cat5 or Cat6.  4 or 5 wire thermostat wire. 5 wire provides a spare in case one goes bad. Some like the flat 4 wire cable that few train vendors sell. It is a little more expensive.

14 for bus, 16 for power drops.  

John Patrick posted:

Just getting back into setting up my old Lionel Train.  .... Again is there any problem to using the phone wire red hot wire to the 16 gauge accessory bus?

if you do not have many lighted cars and you keep the layout small (8' x 8' or less), prewar or MPC Lionel will run just fine with 16 gauge wire throughout.  on a small layout, the number of clean junctions is much more important to power distribution/ loss than run length and 16 gauge is much easier to work with to get the best crimp or solder joints and compared to larger gauges, the delta voltage drop will be in the noise.

Buss gauges: 10 for my 100'  long runs, 12 for medium runs, 14 everywhere else.  Drops are usually 18ga.

The electricity runs out and back, so a 100' run becomes 200'.

An important consideration, different color  wire!  You will need to chase a wire now and then.  Avoid diagonal wire runs, keep it neat.

I'm building a 12x20 layout, I'll be using #14 for all the power wiring, and probably #18 for individual drops.  My longest track power wire run will be around 40 feet as I'll be doing star wiring to attempt to support MTH and Legacy/TMCC without issues.

My layout is 8' X 38', I run a mix of can motored and open frame motored locomotives on Legacy with Dales Signal Booster. I have 14ga. stranded wire for the bus and use 18ga for the drops. Lighting is 100% LED, including passenger cars and locomotives, for layout lighting I use 20GA stranded.

Ray

John Patrick posted:

Lionel also talks about using telephone wire for the switches in that they use very little amps. Again is there any problem to using the phone wire red hot wire to the 16 gauge accessory bus?

That's what I did for my RealTrax switches on my layout.  Switches only use a brief, momentary shot of power to activate.  The rest of the time they sit idle, using no current at all (unless they have an indicator light, which will use very little current).  Shouldn't be any problem at all in powering your switches with telephone wire coming from an appropriately-sized bus.

Mixed Freight, FYI, if one uses the old NJ International switch machines, while the power is only on momentarily (if, and only if, you have them wired to cut power after being thrown), the current draw is quite large and 18 gauge wire is not too large to provide enough power to move them.  If you have the old postwar Lionel 022 switches, the lamps use considerable power (5 watts is what they were rated) and there are 2 of them per switch if you use the Lionel controller. 

FWIW, when I build a grandson's layout with 10 022 switches from the early 1950s, I used direct replacement LEDs to cut power needs and to keep them from burning their fingers on the controller bulbs (which always happened to me 70 years ago).

If you use DZ1000 switch motors, 22-gauge wire is fine as they use tiny amounts of current.

All the wiring for track power and ground is 14 gauge. I wired the power wires in a star pattern and the ground wring shares a common. All power drops to the track are 14 gauge. No power loss to the track at all. My recommendation is to have the power drops to the track the same gauge as the rest of your wiring.  

FWIW attached is a snip from a wire loss spreadsheet I cobbled together a few years ago. At a glance you can compare side-by-side permissible wire run lengths for common wire sizes for various common amperage loads, based on the common out and back scenario, and 2 volts max loss, which is a good value for train wiring. The max suggested load current for each wire size is shown along with the max recommended fuse or CB rating for each size. This sheet has made life a lot easier for me.

Also for more versatility, attached is the fully functional Excel spreadsheet. It has only two inputs: you can select either out and back or one way wiring, and you can select the allowable voltage loss you are comfortable with. Once these selections are made the allowable wire run lengths are all recalculated accordingly. I am putting this out there for anyone to use as they see fit and I make no guarantees as to it's accuracy or suitability for any purpose.  The spreadsheet is not protected in any way, so use it accordingly. Caveat emptor.

Rod

AWG gauge current capacity based on nick-free, stranded, soft copper wire.

open air wire capacities (such as in layout wiring) are much higher than tables based on building standards that degrade capacity based on conduit enclosed wiring.

I have no quarrel with the ohms/foot figures above, but to me it always has seemed that voltage drop on a layout exceeds what the tables say it should be. 

Then there is the effect on command control signal strength.

When I first built my layout, in the early 90s, I used 14 gauge, except for a 4 track storage yard, with 3 blocks per track.  To save money/time, I used 18-gauge multi-conductor cable.  When I added DCS, the signal strength on the rest of the layout was great, but useless on these 4 tracks.  I rewired with 14-gauge, and got excellent signal strength.

RJR posted:

I have no quarrel with the ohms/foot figures above, but to me it always has seemed that voltage drop on a layout exceeds what the tables say it should be. 

...

overlandflyer posted:

....  on a small layout, the number of clean junctions is much more important to power distribution/ loss than run length  ....

even at a perfect terminal strip, crimp or solder connection there will be loss.

overlandflyer posted:

AWG gauge current capacity based on nick-free, stranded, soft copper wire.

open air wire capacities (such as in layout wiring) are much higher than tables based on building standards that degrade capacity based on conduit enclosed wiring.

I agree with your statement, but if you use these much higher current loadings you definitely won't like the voltage losses, nor will your trains! 

Rod