Electrical requirements for new hobby building

[HenryF]

I am planning to construct a new pole barn with a finished and insulated hobby room that will feature a 20'x 30' 0-gauge layout.  I plan to run four trains at once, plus a host of accessories.  What knd of power supply would you recommend and how many amps should the electric panel in the building be sized for, to handle the train-related load?

Thank you for your suggestions!

Henry Fischer, Pine City, Minnesota

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[ADCX Rob]

Your trains will require a 15 amp outlet.

There is no way to know or guess what size the panel will need to be for the barn with incomplete information.

[NeO6874]

ADCX Rob

Your trains will require a 15 amp outlet.

There is no way to know or guess what size the panel will need to be for the barn with incomplete information.

^ This.  

You'll want to talk to your contractor ... but really quick numbers / thinking, you'll want an absolute minimum of two (2) 15 A circuits (1 = lights, 2 = outlets) , although 3+ circuits (or go 20A) would probably be better (required), especially if you're going to want/need more than ~10 amps of power to your layout - or a DCC command station + booster*.

Sub-panel simply has to be big enough to handle the sum of the circuits you're putting in, while still having a little extra capacity (e.g. 50A). Depending on your incoming service from the electric company, you might also need a new home panel (really only if your main panel is full).

This is where "80% continuous load rule" for circuit breakers comes into play -- as with all things, you need to take into account the tolerances of that "15A" breaker (e.g. it might trip at 13.75A load), so you want to give some wiggle-room so you're not blowing the circuit every 10 minutes.

For a 15A circuit, you can load it to 1440 watts (15*120*0.8 = 1440), or roughly 11 of those 4-bulb (32 watt/bulb) fluorescent shop-lights.

*NOTE -- my experience is smaller scales, so your numbers may vary.

[lionelsoni]

Add up the power requirements in watts of all the transformers that you think you might possibly be using.  Divide by 120.  This is the maximum current in amperes that your layout will draw, and probably a conservative estimate of the typical current.  I doubt it will be anywhere close to the 15 or 20 amperes.that a single branch circuit can supply.

[Firelock76]

Don't forget everything else you'll have to put in there.  Heating, air conditioning, refrigerator, coffee pot, microwave oven, TV and DVD player for watching railroad DVD's...

Did I leave anything out?

[cwburfle]

When it comes to electric, I'd be generous. Were the building mine, I'd go with at least two dedicated 20 amp, GFI protected outlet circuits in the train room. (check compatibility with your train control system, I think I read somewhere that one of them didn't play well with GFI, but that does not sound right) Then there would be a separate circuit for train room lighting. I would also make some of the outlets switched. As for the building: In addition to lighting and 20 amp GFI circuits, I'd would want a 220v circuit with enough amperage for a compressor.

[lionelsoni]

If you do provide more than one branch circuit for the layout, keep in mind that the circuits may be on opposite phases, particularly if a multiwire branch circuit is used.  This will affect the phases of your transformers' outputs.  Your electrician can do it either way, but a multiwire circuit is cheaper and easier to run; so that may be what you get if you don't specify.

You may also want to consider putting a switch for your layout outlets in the same box as the light switch for the building.  That will make it hard to forget to turn the transformers off when you leave the building. 

[Rob412]

I have two 20 amp circuits to power my layout. I use one for under layout lighting, a cordless phone, and I also have a large number of lemax carnival, zoo, and other items which operate on 120volts. The other circuit is dedicated to the trains, operating accessories and any other train related power needs (basically the bank of transformers and control systems). Since your layout is 20x30 feet be generous with your power distribution.

Another suggestion if I may would be to have ample outlets along the perimeter of the layout as you will be using power tools of various sorts for some time to build the layout and pulling extension cords everywhere gets old quickly.
Plus pay particular attention to the lighting. If you know the basic design of the layout try to illuminate it to avoid dark spots and shadows some extra lighting now will pay dividends later on.

How many amps does a disco ball use?

[Firelock76]

Disco ball.  I just knew I left something out.

[lionelsoni]

High ball!