O Gauge layout: Proper gauge and colors for connecting AC transformer?

I like red (for hot) to the third rail and black for ground.  Then anything other than red or black can be for a specific voltage.

You should standardize on the colors you use.    Not sure if there is model standard color or not.    Also I woiuld use different color sets for AC vs DC.   But realistically, the runs to the track can be the same.    Make your changes from AC to DC in a control panel near the transformers.    Just route one set of wires to the track.     Be consistent.   If you use black for the center rail in some places, use black for every drop and run for the center rail.

Wire gauge is based on the length of run.    In most cases 14 or even 16 gauge runs to the track should work.   You could be cautious if you have long runs and use some 12 gauge.    If you use command control  systems, you can run a buss around the layout with a heavy gauge such as 12 or 14, and then use 16 or 18 for short drops from the rail to the buss wires.

@Mannyrock posted:

OK,

I got my track, and a small AC transformer, and will run AC to the track and a DC line.   My current transformer is a small 60 watt, but I have plans in the future to get a 100+ watt transformer.

What gauge and color of insulated wire should I buy to hook the AC line to the track? I use 14 gauge, stranded wire from the transformer, out to a far spot on the layout. I do this multiple times with different colored wire (black for ground, red for track, white for lighting, green for accessories, etc.) creating a "spine" bundle of wire.  I then tap off of these spines w 18 gauge, stranded pieces to the track, accessories, etc. For those, I usually just use black and red colors.

What gauge and color of insulated wire should I buy to hook the DC lines to the track (accessories only)? Not sure about DC requirements.

Thanks,

Mannyrock

 

 

 

Color doesn't matter, keeping circuits trackable is.  There are proprietary trends, but no standards that cross trade lines. High voltage ac electrical has code guidlines, but occasionally, even those are bent.

Many of our items aren't even made here. Europe and Asia, etc. have different trends/code in thier designs.  You just can't count on colors 100%.

Red - often hot or + or switched, main bus

White- hot, neutral, switched hot (with red neg. but sometimes opposite.)

Black- hot, ground, or negative or main bus

Brown- sw hot, earth ground, ground, neg.

Green- earth ground, ground, neg. sw/hots.

Get it? 'Cause I never did      I expected standards; red + black - yey, gimmie more... what do you mean sometimes?   (try a pinball machine with only white wires on for fun )

Wire for the 100w now.. Or buy new wire again later. Heck, wire for a ZW if thats a possibility some day. Big wire is nothing but good for us for the most part anyhow.  (some high frequency might suffer under too large or strand counts, not train concerns 99% of the time.)

Chart, measuring and simple math time.... you have the ruler.

The length of wire needed and max amps available at the supply determine gauge needed. Search online for an AWG wire gauge charts(heres a standard). say 8a to 15a(zw) If close, use the larger gauge wire.  Too light a wire = voltage drop.  The amps need gauge to keep the voltage from fading away at a distance.  Stranded wire is also better than solid wire at pwr. delivery. Go up another gauge for solid wire (really should note on the chart if strd.or sol., when in doubt, go large.)   

If you wire over max supply output, it will be less likely to overheat and melt insulation should something go horribly wrong. A fuse here allows you to reduce wire size without as much worry.  Fat wire and fuses? I'll sleep with the layout on.

 Transformer breakers only protect track/wires by coincidence. The design is ment for supply protection and additional fuses have always been recommended.  If your supply puts out 8a, wire handles 10a, fuse at 9a to save the wire from ? cuts, crushes, whatever.

.further along, a splice/drop to a device draws 2a, new wire still handles 10a, leads to device are smaller, fuse again at 2a right at device leads ...next drop of the 10a line may differ.

 

 

You can purchase number books (common, 1 to 45) either of the Big Box stores.   These identification markers can be attached to both ends of a wire (white markers, black numbers).  Black and White are 14 ga. solid track power.  Brown 8 conductor 18 ga. thermostat wire is used for switch control and associated non-derail/power routing.  There are spare wires. 

Is there a reason to use stranded wire instead of solid copper?  (I've always hated trying to strip and then twist the ends of stranded wire.)

I am going to have very long runs.  Right now, my layout will be a 7 foot long  by 48 inch wide oval , with an ampersand type figure eight in the center.    All is continuous track run, and uses two 90 degree crossovers instead of switches.

I can't see any reason not to use 16 gauge wire.  Any good reason not to?

How many power supply coupler stations do you think I need to attach the AC current to the track?  Should 1 do it?  Or, do I have to use several, staggered around the track, to get the power to be consistent?

Thanks again for all advice

Mannyrock

 

 

The majority of the wire, I have worked with, is solid through 10 ga. Stranded for flexibility, sizes large than 10 ga.  18 ga through 12 ga solid to a point is easier to terminate, IMO.  Clockwise circle around a screw, in most cases.  Stranded would require the correct compression terminal.  IMO.    Soldering terminations has been gone from the electrical industry for some time. Solder-less connectors, either twist nuts or compression, both if properly install a very good, trouble free connection.   

Stranded wire is typically more flexible, easier to work with and route, withstands vibration well and will not potentially split or crack as solid wire can.

I use 14 ga. from transformer to terminal blocks and 16 ga from blocks to track and like using red for + and black for - runs.

For a 4'X7' oval, I would probably start with 3 power connections  - one at each end and one in the figure 8 to eliminate any power loss and see how that works. You can add more as needed. You can run your main power to a distribution block and then out to the track - that makes it easy to add more drops, if required.

Errr,   whats'a distribution block?   I understand the concept, but do you buy them or do you have to make them?

Walmart sells 25 feet of 14 gauge Romex for only $10.95.  Wires are black, white and copper.

Would that be the cheapest way to go to get solid wire?    Stripping the cover off, and just using the black and white wire, isn't too hard.

Hobby type rolls of 14 gauge solid wire seem to cost twice as much.

Mannyrock

 

This one is by MTH, but you can find others, possibly cheaper, on the internet. They typically come with either 12 or 24 terminals.

You connect your main power wires to the red and black screw posts and then you can run as many connections to the track as you want from the terminal connections - easy peezee.

You can use other similar things.too. Ground blocks, terminal.blocks, etc are just an easy "splice system", Look at leverlock connectors for a nice connector vs crimps.. .I still solder 99% of my connections. Proper SAE double crimp if I can't use solder. U into a ♥️then sink the V (a good crimper has the heart's top shape) Stranded has more surface area total. Power rides the surface of wire. To large a wire can have trouble with high frequencies (including speakers, etc), stranding helps on higher ranges. With command, Id be using stranded.

@Mannyrock posted:

Is there a reason to use stranded wire instead of solid copper?  As stated elsewhere, stranded is more flexible. Just use Ferrules on the stripped wire. Do an eBay search for "16 Ga. Black Insulated Ferrules" to see what I mean.

I am going to have very long runs.  ...7 foot long  by 48 inch wide oval , Those in my world those would constitute short runs. On my layout, I have some runs that are over 75'. For those I did use 14 ga. With a 100W transformer you can easily get by with 18 ga wire, if you want.

I can't see any reason not to use 16 gauge wire.  Any good reason not to? Nope Automotive speaker wire is cheap and would work just fine.

How many power supply coupler stations do you think I need to attach the AC current to the track?  Should 1 do it?  For a 7x4 layout, I'd suggest a couple of track feeders.  While I do use the MTH Terminal blocks, for this small of a layout it would be overkill.  I concur with Adriatic on the Wago Lever Locks.

 

A lot of choosing a wire is a matter of distance.  Look inside some locomotives (Post or prewar) and you'll see 22 or #20 wire carrying the full power.  

#18 resistance  is .006 ohms per foot.  No problem with that if your transformer is within a foot of the track.  

10 feet of #22 wire has a resistance of .06 ohms, so if you're wiring a locomotive, you don't have to worry about it.

@Mannyrock posted:

Errr,   whats'a distribution block?   I understand the concept, but do you buy them or do you have to make them?

@Mannyrock posted:

Errr,   whats'a distribution block?   I understand the concept, but do you buy them or do you have to make them?

They're called terminal blocks.  Use that as your lookup and you'll see a great variety.

That's why you'll see somewhat.smaller wire inside too. But learn that too soon and your likely to goof and abuse it. Gauge determines length it can deliver x amps before voltage drop is serious.  You can go with #20g if all you'll ever run is a 0-4-0 can motor and two plastic cars..Try that a single PW FMTM and you'll be melting wire iñsulation. Two of them ? 

Just to touch back in other threads and related relationships, the buses used by PW Lionel on dealer displays and others was often not wire, but brass rod or allthread etc, laid along the length of the layout through the braces, seperated by an inch or 5"ish; whatever...

Transformer wires lead to each bus bar on the layout control end (say variable out, 5v lamps, 14v turnout constant, and common bars) It may connect to alltreads through the frame or under and have nuts to secure the wires   Other folk use HO track instead of bars.

Then drops, branched & fused at 90° off the bars to their holes..a. nice and neat "tree" on the underside (wire notches or holes in braces, etc). 

Easy way- Connect to a wire stay near the hole, or feed the hole and have the cat sit on it etc. Draw the wire taunt and eyeball your 90% to the bus bar(s). Cut, strip, and wrap the wire just a turn or 2, solder, repeat. Heat again and pull to remove it (watch spatter, cover with a wet rag to catch any..ouch)

(Note, esp. on dc, common/ground is more important, and often a gauge larger than the positive. On our systems, 2+ power supplies sharing common, the common bus feed should be doubled(etc) in size to handle both suppies maxed amps combined. ...Single 100w