Layout Wire

20 and 22 AWG is too small for track wiring. More info about the size and amount of track on the layout is needed.

It depends on the size of the layout.   See Toy Train Layout Wiring - Wire Sizes

Wire Sizes for Toy Train Layout Wiring

RRaddict2 posted:

Getting ready to rewire my layout. I used 22 AWG wire last time but it seemed a little thin. Does anyone know if 20 or 22 AWG would be recommended?

Certainly not my recommendation. Although I wired our whole layout with OGR "twisted pair" #14 wire, I would NOT use anything smaller than #16.

My layout is small 5 X 10 but from what it looks like #18, 20, and 24 should do it for me. Thanks guys.

RRaddict2 posted:

My layout is small 5 X 10 but from what it looks like #18, 20, and 24 should do it for me. Thanks guys.

Still, I would take heed to the recommendations given, above. For track power, I would NOT use anything less than #16, regardless of how "small" you think the layout is.

RRaddict2 posted:

My layout is small 5 X 10 but from what it looks like #18, 20, and 24 should do it for me. Thanks guys.

With all due respect, its critical to use proper circuit protection by means of properly sizes fuses or CB's. #24 wire is only good for 2 amps, so any of that in the circuit anywhere dictates a 2 amp fuse. Attached is an update of an Excel sheet that I recently posted as a separate thread that gives at a glance what load various wire sizes are good for and their recommended fuse/CB sizes. Not to sound too dire, but if these are not heeded you can have a situation like the picture below. This was caused by a short circuit in the wiring to a Lionel light tower; not sure how much longer it would have been before fire erupted. I removed this piece of wire from under my layout this summer, and immediately went to work setting up a much better system for protection of all small accessory wires. Hope you heed my experience.

Cheers, Rod

RRAddict:

One thing to think about. With respect to current it is not the size of your layout but the size (power) of the transformer you are using and with respect to voltage drop the length of the wire runs. If your transformer is pumping out 7-10 amps, 20 awg or greater may start overheating on you. You will most certainly experience a voltage drop from the transformer to the track which means you will need to crank up the transformer voltage to get proper track voltage. You may want to try this. Figure out the longest wire run you will have and cut pairs of 20 awg versus 16 awg wire to that length.  Attach to your transformer and to the track and measure the voltage at the transformer versus the voltage at the track and see if there is any difference between the two gauges.

As part of writing this post I did  a goggle search on wire current carrying capacity and have to admit I got confused. I saw anywhere from 4 to 11 amps for 20 awg. The 11 amps may be for short runs on chassis boards but this is way outside my area of expertise. If you still wish to use 20 awg wire I would suggest running 12-16 awg from the transformer to a terminal board then making shorter runs of 20 awg to track just be safe and error on the side of caution.

As Susan points out the thin wires are used for turnouts and lighting where current draw is lower or intermittent (on-off for turnouts). The heavier wire is for track power where current draw is continuous.

Let me know how things turn out

Joe

Susan Deats posted:

It depends on the size of the layout.   See Toy Train Layout Wiring - Wire Sizes

Wire Sizes for Toy Train Layout Wiring

Wire Size Uses

• #24 CAT-2 3 pair solid Telephone - Use a combined pair as one wire for turnout control, and use individual wires in pairs for lighting taps in a local area.
• #24 CAT-5 4 twisted pair solid Data - Use a combined pair as one wire for turnout control, and use individual wires in pairs for lighting taps in a local area.
• #22 7 conductor irrigation cable - Control wires for turnouts
• #20 2 conductor thermostat wire - Lighting bus wiring in local areas.
• #18 thhn for AC electrical - Variable voltage feed for turnouts.  Small accessory loads.
• #16 2 conductor stranded lamp cord - Temporary track wire.
• #16 thhn solid for AC electrical - Taps to track from bus wiring.
• #16 thhn stranded for AC electrical - Accessory bus wiring.
• #14 thhn stranded for AC electrical - Bus wire for track on small layouts and accessories.
• #12 thhn stranded for AC electrical - Variable voltage bus wire for track on a large layout and Common bus wire for small layouts.
• #10 thhn stranded for AC electrical - Common bus wire for large layouts.

 

Hi Susan,

Wow.  I thought I was OK with 14 gauge for a power / ground bus with 18 gauge feeders. 

How big is "large" (in your last bullet)?

George

22 gauge wire is far too small for track feeders on ANY size layout. The first time you have a short on the track, that tiny wire will light up like a light bulb filament and burn the insulation off the wire BEFORE the circuit breaker trips!

You need either 14 or 16 gauge wire for track feeders, and you can get it here.

RRaddict2 posted:

Getting ready to rewire my layout. I used 22 AWG wire last time but it seemed a little thin. Does anyone know if 20 or 22 AWG would be recommended?

this sends me back to when i was a kid.  my dad took over the dining room from Thanksgiving through New Years and wired us up a fairly good size L-shaped layout with a tubular track mainline & 3-4 sidings and a loop of Super-O for the new Santa Fe Diesel.  he never used anything but doubled-up solid phone wire to a number of Lock-On connectors.  pretty sure that was in the 20-22 gauge range.

and in all the years of operation, we had very few electrical problems and no fires i can recall.  i sure wouldn't recommend it today, but despite the fact we probably dropped a few volts here and there, it worked just fine back then.

personally for small layouts (all i ever build) i stick to 16 gauge stranded all around.  easiest to work with directly soldered to track, connectors are the bottlenecks anyway and i rarely draw more than 2-3 amps.

cheers...gary

Hello My friends, I use 14, 16, 18, stranded wire on my layout and 3 or 4 different colors too. So when you are under the layout you know what wires are connected to what. It is good to color code your wires on your layout. I also put masking tape on the wires too and write on them too a good idea to do so you do not forget it. Thanks longbow57ca.

Try this site.

www.powerstream.com/Wire_Size.htm

Ed

If you are doing O or S scale trains I would not use anything smaller then 18 gauge wire. Even 18 gauge wire is small depending on your transformer output. The old post war Lionel ZW's could quick fry an 18 gauge wire with a short.

With some of the new transformers(Lionel ZW-C & ZW-L, MTH Z-4000) on the market even 16 gauge wire is too small for them. These transformers are putting out close to 300 watts or more and at 20 volts, do the math; 300 divided by 20 equals 15 amps, so a 14 gauge wire would be needed to be safe. 12 gauge wire, maybe even 10 gauge, would be needed to be safe with the new Lionel ZW-L rated near 700 watts.

If you are doing H.O. then 20 gauge wire should really be the smallest.

Lee Fritz

I used many types of wire depending on it's intended use.
12 and 14 ga THHN for track power busses with 20 gauge track drops (only inches long).
Several types of HVAC multi-conductor thermostat wire for block detection, signal drivers, and Lighting.
I used 4 pair phone wire for the Tortise swich machine drive and position detection.
Here are some photos.

Control panel wiring

Block detection and signals drivers

Carl, that's a very nice and neat wiring job. Looks very professional.

How about showing the Signals on the Train Board and maybe a closer look at your Relays Panel Board.  

Other wise very nice. 

Good Luck, John 

OGR Webmaster posted:

22 gauge wire is far too small for track feeders on ANY size layout. The first time you have a short on the track, that tiny wire will light up like a light bulb filament and burn the insulation off the wire BEFORE the circuit breaker trips!

You need either 14 or 16 gauge wire for track feeders, and you can get it here.

I got my hands on a couple rolls of this wire and it's great. If anyone needs to wire their layout, this stuff would be my choice.

Engineer-Joe posted:

OGR Webmaster posted:

22 gauge wire is far too small for track feeders on ANY size layout. The first time you have a short on the track, that tiny wire will light up like a light bulb filament and burn the insulation off the wire BEFORE the circuit breaker trips!

You need either 14 or 16 gauge wire for track feeders, and you can get it here.

I got my hands on a couple rolls of this wire and it's great. If anyone needs to wire their layout, this stuff would be my choice.

Another recommendation for the OGR wire, good stuff. 

I also used OGR wire for all of my layout's track power wiring. It is very good wire and good for wiring up your DCS system per the DCS Companion book. 

Also as Carl T above, I used the #18 thermostat wire in 2, 3, and 5 conductors for my switches, lights and other accessories. I was against the idea of solid wire at first, but stranded was difficult to find in multi-conductor in smaller sizes. The T'stat wire was very easy to get at Home Depot or Lowes and was also reasonably priced. As it turned out I ended up actually liking the solid wire for what I used it on, it worked out very well.

And to Carl T, very nice and neat wiring job there, looks like it was done professionally.