HI, welcome to the forum.
Here is another location in the forum where this question was asked,
http://cs.trains.com/forums/1264406/ShowPost.aspx .
Hope it helps.
Frank
"If you need a helping hand, you'll find one at the end of your arm."
For an out building/ shed of that size you don't need a 100A service unless your city or town requires it.
Codes and requirements will vary to location. If your jurisdiction allows homeowners to do electrical work and you feel confident enough to handle the task then do so. From your initial question as to unclear what your power needs and breakers, you should be contacting a licensed electrician. Many insurance companies will also frown on this work done by a non qualified individual. Just needed to throw this out there, I don't know the circumstances.
Now as to electrical needs: If your residential service is at least 100A and the busses are not maxed out due to house needs (full electric house,or electric dryer,water heater, AC and range), it may be possible to add a 40-50A 220 breaker controlling a sub panel in the out building. Approved buried cable or conduit is the best way to feed the structure. The grounds and neutrals in the sub panel should be on individual buss bars. Your local codes will dictate if any recepticles need to be GFCI protected. This should be done by use of a GFCI breaker unless only one exterior rec. need be protected.
1) 220, 20A breaker for AC and/ or heat (use of a 220 unit is best for savings for both AC and heat)
2) 110, 20A breakers for recepticles (1 dedicated to all train equipment, the other for Dehumidifier/ power tools and gereral purpose)
1 or 2) 110, 15A breakers for lighting (1 is actually sufficient, but it doesn't hurt to have a spare.
Even though these breakers/load totals 40 or 55A per buss on the sub panel this is within % of load for the main breaker/ disconnect in the house panel (40-50A).
Now this all depends on local codes and the combined total use of your main panel.
Your actual total Amp draw will never see the max of any of the breakers in the outbuilding panel for your intended use. (Unlees you decide to set a full wood shop, compressor etc)
Modeling B&O- Chessie Bob K. www.ssmrc.org
Jeff But it's a dry heat!
I agree with what's been said. Make a list of all the items that will be in the structure that draw power. Consult with a licensed electrical contractor to get advice on how much capacity you'll need to run everything and then oversize it by a significant percentage. It's cheaper to put in extra capacity now, with an adequate number of circuits for possible future use, than it is to try to put them in later. If you plan to cover the electrical and other utilities in the walls, floor or ceiling, be sure to photograph all these things before they're covered. Put a yard stick in each photo to give you a size scale in the photos. Also you might consider marking on the floor the position of the centers of all the wall studs for future reference for attaching things to them. This is a big help when you start drilling holes in your walls to attach bench work, etc. I did this when I finished my train room and the photos have become invaluable in helping me to remember where the electrical wires and other things, like pipes, run in the walls.
Bob
First of all...Welcome aboard.
Ryan and others have already asked good questions and I have a couple more that I see as necessary before I would feel comfortable in giving you an answer, other than a general blanket type answer.
You mentioned AC and heating: Will your heat be electric of some sort (resistance baseboard, stand alone ceramic...?) or would you just need a circuit for a blower or pump with the fuel source being gas, oil, wood...?? This will definitely be a major determine factor in the size of your distribution panel needed for the trainroom.
Another consideration would be: Will the panel for the trainroom be a sub-panel (being powered from an existing distribution panel) or will it have its power input from a main / meter loop? If it's a sub-panel, caution must be taken not to over load the panel that will be powering it.
So...With those two thoughts: Give thought to all the lighting you will want, along with the heating and cooling needs, add in the coffee pot (and what ever other creature comforts) and the power to run the layout. The most basic formula for this is simply adding together all of the amperage draws that you will have, determining the total and size a panel (amperage) that is appropriate for your codes.
For what ever it may be worth; here in MN the code reads that a lighting circuit is 15 amps and a utility circuit is a 20 amps. In my trainroom I have a 20 amp circuit for my "backshop" and gas fired furnace. Another 20 amp for all the transformers to power the total layout and three 15 amp circuits for lighting, all of which are from a 100 amp distribution panel.
Lastly...My rule of thumb is to oversize when possible. You just never know when you'll want or need some additional power...And boy, is it nice to already have that capability.
Give us a few more specifics.
Where are you located? warmer climates dictate more need for AC
how much insulation? built on slab or raised on blocks? other uses besides trains?
a well insulated building the size you describe can be kept comfortable with a
7k BTU AC window unit which will need at least a 20 amp 110 volt outlet.
bench top Table saw / circular saw will draw abt 15 amps
lighting - four 4' twin bulb flourescents abt 6 amps or each 100 watt bulb =1 amp
coffee pot - 7 or 8 amps brewing, 1 amp or less warming. mini fridge abt 3 amps
More info can give you a better answer
Earl
I once caught a train in my pajama's. How it got in my pajama's I'll never know... (sorry, Groucho)
on get qualified electrician.
Otherwise could give new meaning to smokebox.
I'm no electrician but it would depend on the total number of circuits you want in the room.
Also, is the AC is 220 or 110, do you want separate lighting circuits for overhead or track lighting, separate lighting circuits for the sun up/sun down effect, etc....
I would make a list of all the items that will be running off electricity and then get a qualified electrician to consult with your requirements and needs.
Ryan BoudreauxThe Piedmont Division Modeling The Southern Railway, Norfolk & Western & Norfolk Southern in HO during the merger eraCajun Chef Ryan