I am looking at getting the digitrax zephyr dcc unit but i was reading in this book called dcc made easy and in there it says to run 2 14 gauge wires under my layout every 3 feet run 2 22 gauge wires to my rails. Does anybody else do this.
i think most DCC users do(wish i could afford it too…), the feeder wires coming from the 14ga wires are to assure good signal strength throughout the layout; similarly this is done with straight DC, to assure that the same amount of power goes to the farther reaches of the layout.
essentially the feeders keep your locos from running out of power.
hope this helps (and if i missed anything, i hope one of the DCC-savvy guys straightens those out)
A lot of what you will read about wiring is good practice aimed at eliminating, or minimizing eventual degredation of the track power due to rail joiners etc. Now if you are running a small layout, with a couple of loops of track, you could connect the Zephyr to the track in one location and it would likely work just fine. However, if you are building a larger layout, or a layout that you anticipate keeping for a while and doing all the scenery, then I would advise a powerbus to reduce your electrical problems in the future.
There are some other considerations as well, as the power bus allows you to break the layout up into power districts. This is very helpful if you run a lot of trains. You can build short protection in to the power bus design and build detection circuits if you are intending to have signalling and an automated control panel.
So there are good reasons to do it, but there is nothing to stop you just hooking up the layout like you would an old style DC pack and running trains either.
That’s actually good practice whether you’re using DCC or not. Ever notice how a non-DCC train running on a loop of track will slow somewhat at the far side of the loop from where the power is connected? The rail’s resistance decreases the voltage available to the loco.
Since properly sized (that’s important!) copper wire has less resistance than the rails, you minimize that voltage drop at the far end. And since the feeders are shorter, and the load is spread between more of them, they can be smaller gauge.
HTH,
Steve
1 question I have is do you have to insulate the track between the feeders?
You don’t have to BUT if you want to break your track into sections then yes you do.
the sections jpaauwe are talking about are called blocks. They are so you can run multiple trains on DC. If you use DCC you dont need blocks. Just solder feeder wires to the track every few feet and you are good to go.
Dean:
All great comments so far…
How big of a pike are you building? That may determine, somewhat, how you go about the wiring regarding wire size and breaking it into different power districts.
I run a #12 buss with # 18 & 20 feeders. I tend to error on the build it heavy side of things (the old saying “Better Safe than Sorry”) and when it comes to wire, the heaver you can use, the better.
BTW, my first MRR empire was in a basement on Arrowhead Street and I’m now only about 85 miles West, in GR.
The issue of using the buss and the fact that you have a voltage drop at the far ends of the layout largely depends on the rail size also.
I am using Atlas Code 55 (very small size rail) on my N-scale layout which is a fairly good size basement layout, I soldered all rail joints and experience a 3 to 4 volt drop on the far end and the locos would slow way down in that location before running a 12 ga. buss.
…which speaks to the problem with relying on the rails for continuity, even if they were monolithic all the way around! The smaller code acts like a smaller wire, and offers more resistance to the current that the locos want to suck in at the far end from the terminal…if there is only one.
So, as said above, use good heavy wire for larger layouts of all sizes to ensure minimal voltage drop everywhere, and also to avoid resistance (and therefore HEATING wires) as you grow your locomotive stock and require more power in the rails.
While blocks are not necessary; they can be useful.
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Locating short-circuits: Since each block is electrically isolated from all the others, you can focus your search on small portions of your layout oneat a time. As you eliminate each block from the list of possible locations for the short-circuit, you move onto the next knowing that the already-inspected blocks are short-free.
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Turning off unused locos and rolling stock: If each block’s power can be switched on/off, you can turn off portions of track not being used (eg: sidings, yards). This is good if you have locomotives or illuminated passenger cars parked there. By turning off the track power, you also turn off the power for the locomotive and any cars. This also helps elminate the chance you might accidentally select a locomotive you don’t want.
And the blocks (which can be fairly large – 10 to 20 plus feet long) makes it a lot easier to add additional boosters or circuit breakers as you add more sound engines.
Yes, I said to my crew that I would never want any sound engines (as all everyone had run on my layout was steam and I am all diesel in the mid ‘80s) but now I have 6 sound units and others that operate on my layout also are bringing over their sound diesels.
With 50 engines on the layout I had to break the layout into 3 very large blocks (as I have over 2700 feet of track). The sound units just took too much power as the 8 amp booster would cut out when 4 sounds units were on the layout at one time.
With the layout in 3 blocks now I thought that I was good, but over the week end we had an Ops session and again I found that I could get more than 3 sounds engines per block and the block would kick out. Now this is in addition to the other non-sound units running too.
So I guess I will have to break each of these large blocks down even further. Had I not went with sound the original 8 amp booster ran the layout with 50 plus engines fine for 3 years.
Life moves on, just a little more work to do!
BOB H – Clarion, PA
Bob, this seems like a very low number for an 8 amp booster? I run my yard with my 2.5A Zephyr. My boys and I were running trains last night and I was sure that we had more than this running in the Zephyr power district. I went and tried this morning and found that I could run the following simultaneously, with sound on
BLI E7
BLI SW7
Soundtraxx equipped Spectrum Shay, P2K PA1, IHC 2-8-2
I had to run them slow as there was just me and I can’t control 5 locos at once[:)] but all 5 ran no problem.
What are you using for short protection on the blocks? It seems like something is set very sensitively.
simon1966
Yes you can probably run that many. I on the other hand had 50 non sound engines scattered around the layout plus the sound engines.
The real problem was the recovery when someone would run a turnout.
Now if I put in the PM42 with the tail-light bulbs across the PM42, then I should eliminate the restart problem
Also as a side note the Soundtraxx sound units (especially the older ones) did not have as much problem on my layout doing a recovery. I had 5 or more on the layout before I put in the extra boosters and had no problem with recovery!
As it is I am running almost all QSI sound chips in my Atlas, Lifelike and BLI engines.
This is a real problem when they all get together and have a short. We just usally hit the power button on the DT400 keypads and recycle the power and all comes back up. It is the auto-recovery problem I want to get working again.
BOB H – Clarion, PA
Just a side note on power, I had 2 PCM sound units, a BLI sound unit, a Soundtraxx DSD-100LC (not installed but clipped to the track power with a resistor on the motor leads), and 2 non-sound P2K locos all running on my Zephyr. I shorted the rails and it came back without having to lift anything off.
I’m beginning to think the Zephyr is a little different - I’ve had no problems programming the BLI or PCM locos, both on the main and on the program track - yet those with DB150 and DCS100 command stations say they DO have problems. Interesting…
–Randy
Yes I am beginning to believe this also with the Zephyr.
And as for programming, so far I have not had any problems programming the BLI, Atlas and Lifelike units using the QSI sound decoder. But then again I only set the engine number and then OPS mode program the rest as I can use the audio readback (I have a DCS 200 - Digitrax system).
Now this past week end I tried to program an Athearn set with the MRC sound decoders in them and they could only take the 2 digit address setting. The 4 digit address would not program directly. Although I wanted to try it using the individual CVs the owner was satisfied with just a change in address. He could not get his Lenz system to program the engine numbers either!
BOB H - Clarion, PA