DCC Current Draw

[markpaulson]

I am planning an On30 layout that will fill a room 23x10 feet, and operate with DCC control.  In order to install electricity for the room, I need to know how many 20 amp circuits I need to pull.  I currently have the following On30 motive power, all Bachmann:

(2) 2-6-0
(1) T-Boiler Two-Truck Shay
(1) Baldwin Outside Frame 2-8-0 Consolidation
(4) Porters
(1) Baldwin 2-4-4 Forney
(1) American 4-4-0

Eventually I hope to run all of them on DCC, with sound.  I have about a dozen passenger cars and cabooses with Bachmann factory installed lights in them.  I will not be running the structure lighting from my DCC system, and since the layout period is going to be about 1915, I will not be doing a lot of electric signaling.  I will have to have some remote control turn-outs, but not running on the DCC system.  I am assuming I need one 20 amp circuit just for room lighting, so my question is...do I need one or two more 20 amp circuits to run the DCC, boosters, etc.?

Thanks,

Mark

[Nathan]

You will probably only be running about half of your locomotives at on time.  Even if all of them were running, one 15 amp circuit is all you should need to run our DCC pulse other parts of your layout.

[Jim Banner]

Lets do the calculations.

Suppose end-to-end 4' fluorescent tubes for overhead lighting.
14 tubes x 40 watts = 560 watts

Suppose you run all ten locomotives at once.
10 locomotive x .5 amps x 15 volts = 75 watts

Suppose you have many lighted buildings.
200 lights x .050 amps x 12 volts = 120 watts

Suppose you have 100 turnouts using Tortoise switch machines.
100 Torts x .050 amps x 12 volts = 60 watts

Suppose you use a computer for programming decoders.
Computer power about 250 watts

Adding it all up, you need about 1065 watts total.  At 120 volts, that is less than 9 amps.  One 15 amp circuit will handle the railroad and the lighting for it quite nicely.

However, I am going to guess that this layout is in a basement.  If that is the case, there may be times in the winter that you would like a bit of auxiliary heating and depending where you live, you may from time to time want to run a dehumidifier.  So I would suggest running a second 15 amp circuit to a few conveniently placed outlets.  You may never use them for heating or dehumidifying but you will almost certainly use them from time to time for power tools.

Jim