I am getting ready to start wiring my 1st DCC layout. I have read the way to go is to run some 14 gauge wire under the board and connect with 22 gauge wire to the track. My question is , say you have an industrial switching area , or a small yard . do you run this 14 gauge wire everywhere the track goes and run a short piece of 22 gauge to the track , or use the 22 gauge to run from 1 14 gauge wire to multiple tracks , like parellel tracks in a yard.. or how about a passing siding , do you run 1 piece of 14 gauge wire and use the 22 to each track , or 2 parellel 14 gauge pieces.. and what do you think the longest a 22 gauge piece should be
One set of bus wires down the middle of the yard with feeders goign to each track will be fine. People tend to get carried away and think that of the feeder wire is more than 4 inches long it's goign to cause a problem. Scroll dow to the section on Allan Gartner's web sire about "the great feeder experiment" for some tested numbers on just what will and won't work: http://www.wiringfordcc.com/track_2.htm. Unless you're building a 20 track yard, if you run the bus down the middle the longest feeders will still probably be under 1 foot. Put feeders every 3-6 feet along the yard. Don't rely on track joiners as the only way to get power into a section of track.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
In your examples, you need only one 14 guage bus wire and then tap off of it with 22 guage runs to the individual tracks. The 22 guage runs can be a few feet long if necessary without any serious voltage loss.
You could also run a sub buss to the yard tracks. A separate sub buss with some insulated rail joints into and out of the yard will give you a future district as your rail road empire gets bigger. The sub buss can be separated with a 1156 auto bulb for short protection.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
I use the 22 gauge wire bundle you can buy with four coloured wires inside a white plastic tubing on a small spool. I strip off the plastic tubing and use the four wires for feeders, keeping the same orientation of colours between the left and right rails.
I have several feeders in the 3' range and notice no degradation in voltage. I also run feeder pairs about every 6' of tracks, but no more than that. So, the advice given so far, if you need more piled on, is sound. Nothing wrong with joining a length of 14 gauge wire to the main central bus with a small pair of 14 gauge 'feeders' running between them. I do use the 12 volt tail light bulb that will illuminate if a short takes place in that sector. But if you have no particular interest, just join a length of 14 gauge to the bus, and then run your feeders off the sub as you need to...as suggested just above. I have my box-like layout bolted together as four modules, with each one fed via a sub running the length of the module. The main bus runs around the whole in both directions from the Super Empire Builder's DB150 base station.
-Crandell
Hey , thanks for the good info , will help a lot and save a bunch of copper from what i had planned
One last word of advice. The litmus test is the quarter across the rail test. At all points in your yard the short ciruit must shut down your booster or operate a circuit breaker. The most common location for this test to fail is after a turnout where there is no feeder to a spur. I also recommend testing locations farthest from the feeder connection.
All that being said I use #14 AWG bus and #24 AWG feeders in lengths up to 24 inches and have never had a failure of the quarter test.
Have a good weekend.Dwayne A
Only one thing to add, slightly at variance to some of the above.
Don't run your bus down the centerline of your yard (unless you really enjoy standing on your head while looking up at hot solder joints.) Run it down the fascia line, and not too far in. That way, all of your joints can be made while sitting on a comfortable chair in the aisleway - which is likely to produce better solder joints as well as being a lot easier on the bod.
I personally run all of my electricals parallel to the fascia - everything from 120VAC layout service (heavily insulated - former outdoor extension cord) and busses (yes, I have busses, even though I run analog DC) to 4-pair #24 wire cables used to connect indicator lamps between panels. Doing so makes it possible for this arthritic old coot to work for a couple of hours, versus a couple of minutes pretending to be a contortionist.
Chuck (Modeling Central Japan in September, 1964)