Hello all,
I am an 'elderly newcomer' to model RR and the concepts of DCC. I have spent hours researching DCC but I still am puzzled by a couple of issues.
Given that I am planning a rather physically small wall layout in an 8 X 8ft. area, but that it will contain 12 switches all with Railcrew switch machines. decouplers, and a maximum of perhaps three locomotives, what kind of entry DCC power capability will I need?
Will I be ok with a DCC starter with 2 or 3 amps or should I look at 5 amps? I'm considering either the NCE or Digitrax starter systems at this time.
And, in terms of the main power bus, should all devices be connected to the main power bus in my configuration or should I run a separate bus for the switches and from a separate power supply?
In spite of all the documentation that's available online, I'm still not sure as to what would be the proper wiring configuration for my layout.
Thanks in advance for any and all words of advice!
J
"The older we are, the better we were!"
As a Newbie your posts are moderated that means a slight delay. You really need to give us a bit more info, scale and a rough size. For just three locomotives you can get by nicely with 3 amps. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Hi Mel,
Thanks for the welcome!
Apologies... I realized after I posted my first that I had omited some critical details.
Let me try this again. The HO layout is to be on 2ft. and partial 1 ft. perimieter benchwork along the walls in an 8 X 8 ft area, essentially with a perimeter track around the walls and with a coal mine on one side and a branch line engine shed, water, etc. on the other. Both have some switched sidings for coal loading and shunting/storage to the tune of 12 Railcrew turnouts which will be controlled only with fascia mounted toggles and a few Railcrew uncoupling devices. So this puts it in the category of a small layout, I believe. If it seems like an odd layout size, well, I have some interesting challenges as far as the available room that's available.
When researching, I see that some wiring configurations are built on one main power bus while others add a second bus for acccessories, using the main bus for track power only. Being inexperienced, I'm a bit puzzled as to whether this is necessary on a small layout when using, for example, the NCE PowerCab starter system which is rated at 2 amps. Further to that, will the short bursts of current to operate the switch machines have any detrimental effect on the DCC operation on this rather low powered system, and, should I be looking at 5 amps for power?
In terms of the number of locomotives, that is not an issue as I know I'm well below the limit and this is definitely a single operator layout. I'm limited in physical space (as well as age... lol) so i don't forsee any expansion unless I win a lottery and move into a much bigger house!
I have no concerns about the actual wiring techniques; it's more a matter of the planning logistics at this stage.
I hope that clarifies my questions... and thanks again for responding!
Hello All,
As a former electrician, we used to talk about the concept of "headroom".
When calculating a particular maximum load a 10% to 20% "fudge factor" was added to ensure a margin of safety.
This headroom accounted for spikes in "start-up" draw by things like compressor motors.
If you are running sound-equipped or locomotives with Energy Storage Devices (Keep Alive™, Power Xtenders™, etc) these might require an extra bit of "oomph" during their start-up sequence.
Are you converting older DC locomotives to DCC or are you purchasing locomotives that were recently produced?
Motors in older locomotives tend to draw more amperage than those made within the past 10-years.
On my 4'x8' pike, I run up to 8 locomotives simultaneously- -ah the advantage of DCC.
This is the most locomotives running simultaneously. I have a 5 amp booster.
I also have 22 turnouts. To power the turnouts; some thrown in pairs, I use 2 Capacitive Discharge Units (CDUs) and a separate power supply.
All of the turnout motors are 3-wire solenoid type. These only require a "burst" of power to throw the turnout as opposed to a slow-motion Tortoise kind which require a constant power supply.
No matter which turnout motors you use I would recommend a separate power supply.
Two books that you might want to add to your railroad library would be The Complete Atlas Wiring Book and The Digitrax Big Book Of DCC.
Yes, each of these books focus on the products they manufacture but the concepts are valid no matter whose products you choose to use.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
As Mel has pointed out, my replies are delayed due to my 'newbie' classification and so my second reply has yet to be posted, and this is now my third.
First, thanks to all for the advice so far in spite of the fact that additional information I added hasn't yet posted and I apologize again for my negligence. And with more comments coming in, I realize that there is more information that I should have included, ie: what little rolling stock I have and that I plan to have is of new manufacture; locos are 'steam', Broadway Limited sound equipped Consolidation and Mikado.
Everything in fact that I am using is new, as my only previous attempts at model RR was as a teenager and that, I admit, was quite a few decades ago!
So far, as a new model railroad builder, as I used to say at work "I have it narrowed down to 'everything'!"
to the forum. If you are starting out with DCC, I'd go all DCC and sound.
The introductory DCC books like to show lots of boosters and lots of power districts. If you are a loan wolf, you won't be able to manage multiple trains, unless one is simply traveling in a circle. So you will have a consist of 2 or 3 engines and or a single engine doing yard work. The introductory systems will be fine. Which one? borders on a religious argument.
There is no argument that powering the Rapido devices is done with DC power. The thingee that plugs into the wall to supply DC power to various chargers and electrical devices is commonly called a wall wart. They are inexpensive, but come in a variety of voltages and amperages.
I'd go with stranded 16 ga. Solid wire is a bit difficult to deal with. Wire strippers of this style are great. https://www.homedepot.com/p/Klein-Tools-Katapult-Wire-Stripper-and-Cutter-for-8-20-AWG-Solid-and-10-22-AWG-Stranded-Wire-11063W/204660476
Shop around for less expensive versions, that was the first pic I pulled up.
Henry
COB Potomac & Northern
Shenandoah Valley
Ok, thanks again everyone!
I think Henry summed up my proposed operation quite well... "loan wolf", etc. As to my power dilemma, I have a consensus now to use a separate 'wall wart' for the switches and other devices and that solves a mystery for me! And, from you learned ones, I gather that I should be just fine with a starter like the NCE Powercab.
So now I should be able to happily keep planning and implementing the layout... until I find another dilemma and have to seek more guidance.
I feel very encouraged with your help!
Jimko46I have a consensus now to use a separate 'wall wart' for the switches and other devices and that solves a mystery for me!
Some wall warts are of low quality. I suggest using a multimeter to test the output of whatever unit you buy before hooking it up.
Jimko46 Hello all, Given that I am planning a rather physically small wall layout in an 8 X 8ft. area, but that it will contain 12 switches all with Railcrew switch machines. decouplers, and a maximum of perhaps three locomotives, J
Given that I am planning a rather physically small wall layout in an 8 X 8ft. area, but that it will contain 12 switches all with Railcrew switch machines. decouplers, and a maximum of perhaps three locomotives,
JimI would sure look at using a CD power supply for your turnouts.I haven’t had any experience with Rapido products and I was shocked when I saw how much current they take. The uncoupler draws ½ amp at 12 volts, that is a hefty amount but it’s a lot less than the Kadee electric uncoupler at 3 amps. I thought the RailCrew switch machine would be competitive to the Tortoise but defiantly not at 1.25 amps. I sure would think about paying roughly the same amount for the RailCrew as a Tortoise.The RailCrew must be a solenoid type switch machine as it draws about the same amount of current as my Atlas solenoid switch machines.http://www.circuitous.ca/RailCrewSwitchMachine.htmlKinda makes the Tortoise look pretty good.
EDIT:Time for Randy to talk about servo controlled turnouts.
Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
The RailCrew switch motors are solenoids, with automatic cutoff. Yes, they draw a lot, but only momentarily, they are not stall machines, despite looking like a round motor type thing.
They're easy enough to use, and small. A small wall wart may not be the proper choice for a pwoer supply, but rather something a bit heftier.
The RailCrew uncouplers are also automatic, they activate for a set time period, no external timer ciurcuit needed like for a Kadee electromagnet.
Yes, there is always the servo option for turnouts. Commercial system here, doesn't sound like the OP is much interested in building Arduino stuff. But the only real difference is amount of power drawn, and on a smaller layout that's not much of a big deal. I use servos because they are cheaper aand smaller than Tortoise, not because of how much power they draw.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks to all for the additonal information, particularly the cautions about a power supply for the switch devices.
I have now found some online information about power supply options for the Railcrew switch machines which I will have to consider. This is becoming quite a challenging but enjoyable learning experience!
Newcomers to DCC are sometimes confused between the capabilities of DCC and the requirements. Switches, more commonly called "turnouts" in the MR community, can be controlled by DCC, but they don't have to be, and many of us still use an old-style control panel for turnout control.
Another cautionary note about those wall-warts: They typically do NOT have circuit breakers. So if you overload one or you short it out for more than a moment, the internal fuse in the wall wart blows. These fuses are not replaceable. You are left with no power and an ugly black paperweight. Get a bunch of fuses rated a bit less than the supply, and a few fuse holders.
Your DCC power is a precious commodity. Reserve it for the trains. Yes, it can power switch machines and light buildings, but resist that temptation. All that other stuff should get its own power source.
It takes an iron man to play with a toy iron horse.
Thanks MisterBeasley for the comments and advice! I'm grateful for all the help.
I have been on Amazon and other sources looking at 12v power supplies that are something above the simple 'wall-wart', and there are dozens. Many in the $20-$40 dollar range offer various current outputs, short circuit and overload protection, etc. so I assume one of these will suffice. But I wonder if I should get a lower current rating, ie. 2 or 3 amps or should I aim for something in the 5-6 amp rating, or higher? I suppose if it has some overload protection, inordinate current draw from a short circuit, whatever, wouldn't be a problem...?
Or, am I simplifying something that is more complex than I understand at the moment? Again, this is largely to operate 12 switch turnout devices and a few uncoupling devices.
Thanks again everyone for any advice!
Jim
Before you make a purchase decision, read the recent threads involved with circuit breakers. My unsolicited advice is that you buy a power supply with enough 'headroom' that it will still serve if you expand later, then use fast-acting breakers to limit current to individual sections.
Remember that amperage actually drawn is relative to load; you would be paying little if anything to run a "5A" power supply over a "3A" one if your peak load was only a couple of locomotives.
Think of this a bit like a faucet ... with voltage being like the water pressure. The actual 'peak' volume of water that can be delivered is a function of faucet size, but up to fully open, the amount that goes through is dependent only on how far you want it open, not the maximum size.