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Discussion Boards => General Discussion => Topic started by: RJP on April 11, 2012, 01:08:14 PM

Title: bus wiring
Post by: RJP on April 11, 2012, 01:08:14 PM
I'm in the process of installing a bus beneath my dcc n scale layout. I'll follow the basic track layout as others have suggested but I'm wondering if the two wires (+ and -) have to return to the power source to create a circuit or can they be one-way?
Title: Re: bus wiring
Post by: Rangerover1944 on April 11, 2012, 02:22:23 PM
No don't make a complete loop, don't connect the wires from start to finish. Just dead end the wires with a wire nut on each wire. Jim
Title: Re: bus wiring
Post by: RJP on April 11, 2012, 02:37:20 PM
Thanks Jim...
Title: Re: bus wiring
Post by: phillyreading on April 12, 2012, 07:11:33 PM
You can use wire nuts to connect the wires or you can solder the wires for a better connection. Use wires heavy enuff to carry the electric power.

Lee F.
Title: Re: bus wiring
Post by: Doneldon on April 12, 2012, 09:28:05 PM
RJP-

Use 14 ga wire, like lampcord, for your bus wires. They can be in a loop if your layout isn't long but it will never hurt for them not to be in a loop. Keep your jumpers (22 - 28 ga) as short as possible. Six inches max is a good standard. And run those feeders quite often. I have my layout wired so electricity never has to travel across more than one rail joiner. That's pretty easy with flex track. If you are using sectional track, you might try less frequent feeders, just to save time. You can always add more feeders later if you find places where your trains don't operate with full reliability. Also, consider suitcase connectors. They are a little pricey but they make wiring oh so much faster.
                                                                            -- D
Title: Re: bus wiring
Post by: phillyreading on April 13, 2012, 03:39:14 PM
Suitcase connectors, if it is what I think they are-are junk!
The type connectors that I have used that have a cover to them and you first insert the wires, then close the cover, sort a quick connector, allow the wires to come loose too much and are more of a problem.

Crimp style connectors work well.
Solder the wires for the best electrical connection!! Do it right the first time, so you won't be using colorful curse words later.

Lee F.
Title: Re: bus wiring
Post by: Jerrys HO on April 13, 2012, 06:55:31 PM
Depending on your layout style, I have found the star technique to work the best on my U shaped layout. I had done alot of reading on this and found it works well.
As pointed out keep your feeders to a minimum 6 inches and solder them.

Jerry
Title: Re: bus wiring
Post by: Doneldon on April 13, 2012, 11:58:12 PM
Quote from: phillyreading on April 13, 2012, 03:39:14 PM
The type connectors that I have used that have a cover to them and you first insert the wires, then close the cover

Lee-

You need to crimp the metal blade before you close the connector for a proper connection. I've had
good results with them used that way. The crimp connectors are pretty good, too, though not as quick
to use as the suitcases. I think the proper name for suitcase connectors might be "insulation
displacement connectors."
                                            -- D
Title: Re: bus wiring
Post by: Pacific Northern on April 14, 2012, 12:07:56 AM
I have seen suitcase connectors that are made for specific wiring, 16 gauge for the main and 20 gauge for the feeders. I used these and they work great. I have yanked hard on the wires and they are not coming out.

Beware though that there are also some suitcase connectors that say the are good for a number of wire gauges. They were marked as 14 to 18 on the main and 20 to 24 for the feeders, I would be wary of these. I found those at my auto supply dealers, the ones I bought are from micro mart.

I will only buy those made for specific wire qauges and not the one size fits most style.
Title: Re: bus wiring
Post by: mabloodhound on April 14, 2012, 09:55:04 AM
Also, don't forget to loosely twist your two bus wires....don't run them parallel.   Separate wires (not lampcord) and different colors (ie: red & black)  will make it easier to attach and identify your track drops to them.
Title: Re: bus wiring
Post by: Doneldon on April 14, 2012, 03:59:47 PM
Quote from: mabloodhound on April 14, 2012, 09:55:04 AM
Also, don't forget to loosely twist your two bus wires....don't run them parallel.   Separate wires (not lampcord) and different colors (ie: red & black)  will make it easier to attach and identify your track drops to them.

Twisting buss wires isn't necessary unless you have long straight runs with the buss wires close to one another. If you use lampcord and are worried about this, just twist it two or three turns per foot and you'll never have a problem. Lampcord is easy to separate to attach feeders and will serve to keep things organized under the layout. The best things about lampcord are that it has 16 ga stranded wire and it is cheap. NM cable is cheaper yet but it is a pain to access the enclosed wires in the middle of a wire run. It also has 14 ga solid wires (three or four of them) so it is more difficult to string in tight quarters under a layout.
                                                                                                                                                                                                                         -- D
Title: Re: bus wiring
Post by: Rangerover1944 on April 14, 2012, 07:53:05 PM
Wow from a simple question of I thought connecting the buss wires back to each other to form a complete loop.

I used #14 solid romex house wiring, cheaper buying it at Lowes, Home Depot and far less than #14 at a local hobby shop. Any wire for that matter!

I used #20 braided wire for the feeders 6-8" long, but on every length of track. Using flex track that means every 3 feet and sometimes less. Every piece of track needs something more than track connectors to carry the current because no matter how tight they may be, sooner or later they will fail. Learning experience from 40 years ago. A small piece 1/4-1/2" of bare braided wire twisted and soldered on each rail on the joints of small sections of track is what I did if not using feeder wires from the buss. I don't believe in suit case connections at all, the crimped method I do use sometimes but solder is the only method that' reliable. I also am a firm believer of soldering feed wires to turnouts for very reliable, free of problems operation so common on turnouts.

Twisting the buss wires I haven't done and the longest run I have is 68'. This is not what's considered continous in my mind or knowledge. My layout is modular and I installed wiring blocks to be able to disconnect it without undoing a whole lot wiring if and when I move. This is my last layout at 68 years old. I also have districts or blocks if you like as in DC wiring. I can turn off certain areas, good for finding shorts.

I think I know that there is a certain noise of frequency that is associated with DCC and spikes in power if you run more than 30' continuous buss lines if your buss lines are separated. It's a technical thing and can only be measured, I believe, by using an oscilloscope. There is also use of a capcitator and a resistor I've read somewhere to alviate the noise and spikes of power. Twisting the wires however is the recommended fix. Obviously you cannot twist with the feeders soldered.

Here is more information on track wiring. Jim

http://www.wiringfordcc.com/track_2.htm

Title: Re: bus wiring
Post by: NarrowMinded on April 14, 2012, 08:26:08 PM
If your worried about the Loop field produced by buss wires then you should twist them atleast 7 turns per foot.

NM-Jeff
Title: Re: bus wiring
Post by: Rangerover1944 on April 14, 2012, 09:10:02 PM
Jeff a few posters brought up the "twist wire" comment and I thought I would explain the need to do so. I personally don't have a problem with it on my 11'x17' layout. I would think on a club size layout might be a problem. Jim
Title: Re: bus wiring
Post by: Desertdweller on April 14, 2012, 09:41:11 PM
I remember when DCC was first introduced.  A major selling point was:" you only need two (2) wires to control your whole railroad!"  A corollary to that was that DC layouts were obsolete because they required too much track wiring.

Suitcase connectors are large and sometimes don't work right.  If they don't grab the wires correctly the first time, they cannot be re-used.  And yes, they do get expensive if you have many to install.

I do use suitcase connectors to hook track feeder wires to my common rail bus, to avoid the use of many small barrier strips for the common rail side.  Since they are feeding into the same side of the circuit, they do not have to be detached for trouble-shooting.

I run only regular DC, and find it is the best value for the money for me.

Les
Title: Re: bus wiring
Post by: Desertdweller on April 15, 2012, 10:25:17 PM
I want to mention another reason for staying with DC.  I think it is inherently a safer system, as there is not a constant voltage on the track.

As has been mentioned here before, leaving a DC locomotive standing on DCC track is apt to destroy it.  This is not a problem with DC, as when the loco is left standing, power to the track is off.  With DCC, even if the throttle is "off", power is still in the rails.

Les
Title: Re: bus wiring
Post by: Rangerover1944 on April 16, 2012, 06:00:10 PM
Les I give you all the credit in the world. I'm quite sure that they are many many more DC layouts and model train buffs that don't buy into DCC. It can be costly especially if someone has a desire to add more amps, you know what they say "the more the better". I've heard of people applying 8 and 10 amps to their pikes only to have a derail and litterly weld the wheels to the track. Not smart to overdo things either, everything has it's limits.

But once I found control of 2 trains on the same track, one going slower or faster at my command, I never looked back. Stay with it if you're comfortable with, trains are trains and DC users are not looked down upon by me and lots of others. Enjoy and have fun that's what's important. MRRing is cheaper than a therapist, at least for me, it relaxes me and I forget the daily boring thing of doing adult stuff. LOL a 68 year old kid who still plays with trains. Jim
Title: Re: bus wiring
Post by: richg on April 16, 2012, 06:27:50 PM
The real issue with going from DC to DCC is the fact that this is a bigger step then most realize. Manufactures try to simplify this but many still do not realize they have to do some learning.
People want to use what they know as a basis for new technology and that gets them into trouble.
Making assumptions with DCC gets some into trouble.

Rich