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What size wire do I need?

1939 Views 5 Replies 5 Participants Last post by  deeredaze
 I still haven't  read enough about track power so far. Keep in mind my lack of understanding for anything electrical.  It still makes me wonder what size (gauge) of wire I need to be able to run my trains outdoors. I have heard that 14 gauge is OK. Is this true? Does the power supply dictate what gauge wire I should use? What about number of locomotives running at the same time? What will the maximum length of track  that 14 gauge is good for?  I'm sure that the longer distance I go, the heavier the wire should be.  Is speaker wire a consideration, since it is two wires side by side already? Should I use separate wires instead? Is stranded wire better than solid to solder to the track? Do I have to bury it in conduit if it is not rated as underground cable? Would it be OK to just bury it in a few inches of sand to prevent any cuts to the insulation? How deep does it need to be buried? Just under the surface, or is it better to be like 6 inches down or so? Does the frost heave  break any wires? How many feet apart should I feed the track? I would guess that I should solder all joints and connections also.  What should I use to waterproof the connections underground? Will liquid electrical tape work, or is there something better?
  OK, I'm sure I have exceeded the amount of questions for one topic! I look forward to all your ideas and thoughts. I plan to lay track this spring, so I need some ideas before I start digging and live to regret what I do ! Thanks.
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Depends mostly on:

1. How much current you'll be drawing.
2. How long the wire has to be.

Realize, your locos are wired with fairly small stuff, but these wires aren't very long.
I have used Malibu outdoor lighting cable with good results.  It's available in 12 and 14 gauge, is made to be buried underground, already has two conductors, and is readily available and relatively inexpensive.  Either 12 or 14 gauge will work, but I opted for 12 ga due to its slightly lower resistance over distance (insignificant I'm sure, but given the choice, why not?). 

I'd recommend a good silicone caulk to waterproof the splices after taping or shrink tubing them.  Press the caulk around the splice with wet fingers (spit works) to insure a good seal.

I soldered two or three sections together but left unsoldered joints between these to allow for expansion and contraction.  Brass track expands and contracts quite a bit.  I soldered feeders to every soldered section.  I found this far easier to do after the track had been out in a sunny day for a while and had warmed up.  Less heat was sucked from the iron.  BTW, you need a good heavy-duty soldering iron to do this.  I prefer soldering irons over guns.  I'd also recommend caulking the ends of the feeders to prevent water from wicking its way into them.

Some people run PVC conduit underground within which to run their wires.  I didn't find this necessary myself since I was using cable designed to be buried underground.  Your needs will depend upon how much foot traffic you have in the area, how much animal traffic, whether or not deer will be walking through the area, whether or not a lawn mover will be employed there, and a host of other things relatively unique to your situation.

Turnouts should be installed using rail clamps, not soldered into place.  That makes them easy to remove for servicing and maintenance.

Hope that answers some of your questions.  :)
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My Handy Converter program will show you the current capacity of various wire sizes. It also lets you play with wire size and length of run to determine voltage drop.

Wire Size Demo
I used two wires, 16 gauge, and ran them like jumpers.  This is not the ideal solution.  I rewired the railroad last summer with outdoor lighting wire, I think 14 gauge, and ran from a termnal to each power point.  This works much better and I have seen improvement in operating.  

Next question for you: Brass or Stainless?  I prefer stainless and have not had to clean the track (compared to brass) nearly as much.  I use an Aristo track cleaning car to get dirt and stuff off the track, and the trains run and run and run.  Brass is much more time consuming since the oxidation does not conduct electricity. 

  Thanks for the info guys. Its a start.  I like the idea of silicone for waterproofing. It works for everything else too. Good idea on the rail clamps also.

Dennis, is the wire you mention stranded or solid? I still need to check into the whole soldering iron thing. I have heard of all kinds of high wattage necessary to do the job. What do you guys use?  I've  heard resistance soldering is a good way to go. Any thoughts?  Brands?  Wattage?

  Stan, you have a cool website. Lots of interesting things to check out. The Handy Converter program sounds really, well, just plain Handy! I just finished reading a back issue of Garden Railways where someone was describing the Swiss railways up in the mountains. Now I actually get to see from your pictures how spectacular the scenery really is! I really  like the tall stone arched viaducts and rugged terrain. It looked like it was an awesome train trip!

  So far, I'm starting out with brass track. I have a few pieces of stainless. I like the benifits and I want to use SS, but it is more costly. Yes, the price of brass keeps going up, unfortunately. The part I don't like abot SS  is not being able to solder  feeder wires to it. If you still have to clean SS, then its not as maintenance free as I think it should be. Maybe someday I'll convert to SS.

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