Electrical Safety and Garden Railroading

Written by Paul D. Race for Family Garden Trains

Garden railroading mixes large scale model railroading with all the challenges and delights of gardening, water gardening, and landscaping. What doesn't always mix so well with a naturalistic setting is 110v AC "house current" power (or 240v "mains" outside the US) . Even low voltage wiring is more complex outdoors than it is indoors. Unlike indoor railroading:

• Routing permanent power to a garden railroad frequently involves burying cables or other labor-intensive operations.
• Large scale locomotives require more amperage than indoor trains.
• Large scale railroads typically have longer track runs than indoor trains, making it more complex to get power to the far end of the railroad.
• Garden train operators are frequently grounded by actual contact with the ground, so there is greater danger of injury from misrouted electricity.
• Running wires to accessories, turnouts, etc., is much more complex, since you can't exactly crawl under the table.

You can take the power pack that came with your starter set outside, hook it up, plug it in, and run your trains. But that doesn't mean you should, at least as a long-term solution. Not only will you outgrow that device as your layout grows and you run larger trains, it also isn't designed to be exposed to the elements. If you leave it outside for long, dampness will age it quickly and endanger you or your family, especially if you're running an extension cord from an outlet that isn't ground-fault protected. As if physical danger weren't enough, you also have to face the fact that powering accessories from the same power pack that runs your train is more complicated outdoors than it is indoors.

Garden railroaders usually address the complexity and safety issues of running electric trains outside by one or more of the following approaches:

• Avoiding wiring altogether
• Avoiding 110v (or 240v) AC in the garden
• Using 110v (or 240v) AC more safely
• Planning ahead

Avoiding Wiring Altogether—Some garden railroaders avoid the problems of routing electricity in the garden altogether. A few approaches they use include:

• Converting their locomotives to battery/remote control operation. This means that they don't have to worry about power supplies or about getting power to and through the rails. For a discussion of the advantages and disadvantages of battery/remote control operations, refer to the Family Garden Trains article Large Scale Power and Control.
• Using solar panels to light their buildings—This can be relatively expensive and is not always effective visually, since the solar panels must be exposed, and the amount of light that these solutions produce is minimal, but the technology is improving. Even garden railroaders who run low-voltage wiring to most of their buildings occasionally use a solar solution in a remote cabin or some such that would be a hassle to wire otherwise.
• Using manually powered or air-pressure powered turnouts—Many remote control users follow their trains around anyway, so throwing turnouts by hand isn't a big hassle. Others, who wish to operate their turnouts by remote control have adapted Del-Air air pressure systems or built really long "choke cables" to do the work.

Avoiding 110v (or 240v) AC in the Garden—Other garden railroaders, who use track power and don't mind running wires, reduce the danger inherent of having 110v AC (or 240v outside the US) "live" in an outdoor setting by using only low voltage out-of-doors.

• Many garden railroaders keep the transformer or transformer/rectifier part of their power chain in the house and run only low-voltage wiring out to the railroad.* That wiring is typically connected to a rheostat (throttle) or to a remote-control receiver (like the Crest 55471), which controls the voltage that actually gets to the rails. Most rheostats and receivers should be taken inside between sessions, but LGB insists that the funny-looking 52120 rheostat is safe for continuous outdoor use (although GR editor Marc Horowitz recommends tying a plastic bag over it to keep it dry when not in use). Hobbyist Walter Sheldon says he has had five similar LGB controllers mounted outside for about 10 years with no problems except some paint fading.
• If you do run only low-voltage wiring to your railroad, remember also to run a line of 18v ac to power your accessories.
• Low voltage lighting circuits designed for outdoor use are relatively inexpensive and easy to adapt for lighting garden railroad structures, etc. If you take this approach, be certain to match the lighting of your accessories to the voltage of the circuit—a 12v bulb on an 18v circuit will burn out quickly, but two 12v bulbs in series will last for years, and still be bright enough for most purposes. A big advantage of this approach is that you don't have to schlep anything out and in when you want to see your town light up.

Using 110v (or 240v) AC More Safely—Let's face it, many of us have AC running to our pond pumps and patio lights anyway, so going to extremes to avoid running it to our railroad also may be overkill. If you do use AC in or near your garden railroad, here are some tips for improving safety:

• Use GFI (ground-fault-interrupt) devices to protect all AC circuits running outside or to train sheds, garages or other outbuildings you use. (Outside the US, these are called RCD—for Residual Current Device—also "earth leakage devices.") Such devices shut off power almost immediately if they sense that electricity is coming out of one wire but not going back in the other one (maybe because it's finding its way through your feet into a puddle). Nothing can make an AC circuit electrocution proof, but GFI's reduce the risk. Don't assume that your external circuits are protected because there is a GFI somewhere in the house. For less than $10 you can buy a GFI that replaces a "normal" outlet—just be certain that you turn of the circuit breaker that powers that outlet before you try to replace it. Once you've installed the GFI, test it periodically with the button on the front.
  Hobbyist Ray Turner recommends having a separate GFI for each AC circuit you use outdoors, if possible. That way if something does trip the "interrupt," it's a lot easier to troubleshoot than if your pond pump, floodlights, railroad, and jacuzzi are all running off the same GFI.
• Be professional about buried 110v or 240v lines.
  • Don't bury 110v AC lines anywhere where you are likely to be digging frequently. For instance, you may consider burying them under a sidewalk or retaining wall; don't bury them under a "garden plot" where you may be moving deep-rooted plants in the future.
  • Make certain you use wiring that is certified for outdoor and underground use.
  • Make certain that the entire circuit is properly fused and GFI protected.
  • Make certain that you bury the wire at least as deep as local regulations specify (around here, that's 12" deep for GFI-protected lines, 24" for others).
  • Mark and map the location of the buried line so you or your landscapers don't hit it with a shovel or backhoe.
  • Never, ever run 110v or 240v cables in the same conduit or close to low-voltage lines. Should something cause the lines to short to each other, your accessory wiring or track could be charged to house current ("mains") levels, resulting in a potentially fatal risk.
  
  
• Keep AC devices protected from the weather. Garden railroaders whose railroads abut the back porch often put their power supplies and controllers into "consoles" they can unplug and set up against the house out of the rain and cover when not in use. In fact, any solution that reduces the hassle of schlepping power and control devices in and out reduces the likelihood that someone will get lazy and leave "indoor-only" devices out where they are exposed to too much moisture, UV, and temperature extremes.
• Have a firm "demarcation line" beyond which 110v power does not intrude, preferably at the edge of your railroad. That way, you don't have to worry about whether that cable you fished out of the soil when you were trying to hook up an accessory was high or low voltage. And once you've implemented such a boundary, don't defeat it by running extension cords all over (or worse yet burying extension cords in mulch or soil).
• Shut off AC power when not in use—Even if you leave AC running to your pond pump or your patio lights 24x7, consider installing one "master switch" that shuts off all other AC circuits when you're not using them. If the only way to do this is to run separate lines to your garden, that is a small price to pay for the safety of your family.

Planning Ahead— No matter how you plan to power your locomotives and accessories, good planning will increase the longterm safety of your railroad.

• Plan ahead where you will locate the demarcation between "house current/mains" (110 or 240v) and low-voltage (in the house, at the edge of the garden, etc.), then don't defeat that safety factor by running extension cords, etc.
• Use different kinds or colors of wires for different kinds of electricity. Though you can use wire intended for running 110 or 240v wire underground to conduct low voltage, you shouldn't , because that increases the risk that someone will mistake a 110v or 240v line for a low voltage wire. Also, using different colors for low-voltage AC and for low-voltage DC will simplify your life when you're wiring accessories and track.
• Bury twice as much conduit as you think you'll need, and run strings through each segment so you can fish the wire through easier.
  • Use strings made of nylon or some other synthetic material so they don't rot in the soil and become useless by the time you need them.
  • Also, remember to tie a new string to any wire you drag through so you don't lose your ability to fish the next wire through the same conduit.
  • Always use separate conduit for high and low voltage
  • Keep in mind that you may want to automate or light some accessory that doesn't exist yet. PVC is cheap; workarounds because you didn't plan can be expensive and time-consuming.
• Plan for efficient distribution of power to track and accessories. Whether you use wiring busses, or some other technology, think ahead and be consistent, so you don't find yourself running lines willy-nilly (and maybe hooking things up in dangerous combination) later on, when you have to add one more accessory or track segment you didn't plan for.
• Good indoor practices for routing low-voltage power to track and accessories can be adapted to work outdoors if you are mindful of safety issues, and if you make certain to keep your switches, busses, etc. weatherproof (or keep them sheltered from the environment, in which case you should be able to get away with "weather resistant").

Paul

• The transformer consists of two coils of wire that reduce 110v (or 240V) AC to low-voltage AC (usually about 18v). Not only do the lower voltages match the requirements of Large Scale locomotives, they are also much safer to use. In addition, many accessories that we use to automate our railroads, such as switch machines, require low-voltage AC.
• The rectifier converts low-voltage AC to low-voltage DC (required by most Large Scale locomotives).
• The rheostat (sometimes called a throttle) reduces the DC voltage to an amount controlled by the operator (so the train doesn't run at breakneck speeds.)

Some "controllers," such as the LGB 52120 include a rectifier as well as a rheostat, so they may actually use low-voltage AC as input. But don't take unnecessary chances with your equipment. If there is any chance at all of a rheostat-only controller being attached to the power supply, make certain there is a rectifier in the circuit, too.

• Walter Sheldon:
• Tony Cotton:
• Dick Friedman
• Ray Turner

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