I realize this subject has been mentioned before but I need to know if the 12 gauge wire I intend to use needs to be soldered in one loop or can I leave it disconnected like DC?[:I] Thank you for any and all help.
Archie
Do NOT make a loop.
The only ends that should be connected to anything are the ends connected to your DCC system. The other ends of both wires need to be free, touching nothing that could close the circuit (causing a short-circuit).
BZZZZTT! Wrong answer. This myth just won’t go away.
It is perfectly acceptable to loop the buss wires if that makes you feel good. It isn’t necessary, but it certainly isn’t harmful.
Think for a moment about all the folks with loop-type layouts who are using DCC. In these cases, the rails complete the electrical loop even if the buss wiring itself doesn’t.
Before I tore my layout apart to expand it, I had two of those loops (inner and outer main lines). It worked fine.
On the other hand, the throttle/command buss shouldn’t be looped. But since the OP refers to “the 12 gauge wire” I don’t think that’s what he’s asking about.
HTH,
Steve
Counter point. the best way to runn wire is in a star pattern with the booster in the middle and the bus going out from it. This allows short runs under 30 ft in most cases which is well with in the range of #12.
Take the rail out put to a terminal block and then send out legs. Simple
P.S.
I use a Euro style block at the end of each leg for expansion and protection. Euro block can be cut so you can have just 2 connections for the ends.
Looping the power feed is not a problem as long as you don’t swap wires.
The looping may even be helpful in minimizing voltage drop if you have a VERY large layout.
12 gauge wire is fine as well. It will easily carry all the power any normal booster can supply.
You might wi***o separate the layout into “zones”, each protected by its own circuit breaker or light bulb. Put the protective devices into the section feeders, not the main loop. That way a short will not shut down the entire layout.
BUT… you have to be clear and state that you should not form a loop connecting the two wires together (eg: black to white). An all-white or all-black loop is fine. Just do NOT connect them together. In order to avoid any confusion, its best to avoid forming any loops at all.
Correct me if I’m wrong; but aren’t the power buss and the “throttle/command buss” (as you called it) the same thing (regardless of whether its DC or DCC) ??? Aren’t power and control signals carried on the same wires ??? If not, just how many busses do you need ??? [%-)][%-)][%-)]
If you read Camarokid’s posting carefully, he is refering to his main buss (12 guage wire), and whether he should leave them disconnected like in DC.
Depends on the DCC system. With Digitrax, the Loconet is both the command bus and the throttle bus (and signal bus if you use Loconet-based detection and signalling like BDL-168’s and SE8C’s). With NCE and CVP, there is a seperate bus for the throttles and command bus.
–Randy
I was under the distinct impression that Camarokid was asking about the wires that connect (via feeders) to the rails themselves. Not the wires that link together the various components of the DCC system.
Or are you saying that some DCC systems require two (or more) sets of wires connected to the tracks – one for electrical power; another for control signals to the locomotive decoders ??? [%-)][%-)][%-)] I thought that only one set was required, regardless of the DCC system. If multiple sets are required, then why does everyone say that wiring a layout for DCC is easier than for a DC system ??? [%-)][%-)][%-)]
No, track power is a single set of wires from the booster. The other connections would be for additional throttles or boosters and is not part of the track power. To have walkaround control you would need to run at least two sets of wires undr your layout. One for the track power, connected via feeders to the track, and a ‘throttle bus’ which varies depending on your DCC system but commonly uses 6-wire phone cable (for Digitrax and NCE).
–Randy
I believe he is asking if the two main leads (what we call the bus) can be looped back so that each end is screwed into its original terminal on the controller/booster.
Yes.
Can the wires that originate in separate terminals (posts) on the controller/booster be wired together where they end, i.e., with a marett?
Heck, NO! Big phzzzztt if you do that.
Do I loop the bus wires back to their posts?
No. Should I? No, my bus is only 10’ long. If it were 30 feet long using 14 gauge wire, I would probably benefit from looping it for the same reason that looping a water line maintains pressure over the distance and numerous draws from tap-to-tap.
[B)]Yes, I was only referring to the main bus wires. I should have been more specific in my post. I don’t think well late at night.
THANK YOU ALL FOR YOUR HELP.
My layout is 24’ by 16’ and is relatively flat so I won’t have much of a power draw down for the two inclines and descents I intend to build.
I will be using my MRC 2000 for awhile but will probably upgrade to the Prodigy Advance when I fini***he trackwork and work out all the bugs.
Again, thank you all for the help. I have my answer.
Archie
Yes but others brought up the throttle/command bus when the answer was given that the TRACK bus CAN be looped but the throttle/command bus should not be.
Bottom line: TRACK POWER BUS can be looped to itself - just don;t get the polarity wrong, or it’s a dead short. The THROTTLE and/or COMMAND BUS should NOT be looped to itself - some systems can handle this in some cases but others cannot, safest thing to do it not loop these.
–Randy