A few weeks ago I posted that I was given a DC HO layout, 4x8, two complete loops and a few yards. It was the cover story in MR December 1992, “Building the Berkshire Division” I connected it to my DCC, NCE PowerPro 5 amp. The DC layout uses 24 Ga tel wire. It has 3 blocks, I connected them all to my DCC. The total length of wire is about 3 feet. Everything works fine.
Should I run a new power bus with 14 Ga wire and drop down some feeders?
Thanks for suggestions
Bill in CT.
My theory. If it’s not broken, don’t fix it. Maximum recommended feeder length is about 3’ anyhow. I think you’ll be fine. If you notice your trains slowing down in some spots from power drop, you can always add a feeder or two.
If there is only three feet of wire between your DCC booster and the track don’t worry about it. The need for 14 guage wire relates to the resistance in long runs, but in a short 3 foot run there just isn’t enough resistance to worry about.
Barry Draper
Bill I as well think you are fine. Some of my feeders are 16’ long and 14 gauge. That was before I knew better but as stated “if it is not broken don’t fix it”. Boy I learned the hard way trying to make things better that worked fine. Just have fun.
Cuda Ken
In the interest of safety, the current rating of 24 guage solid copper is 3.5 amps for chassis wiring (meaning short runs). The recommended current rating for 24 guage when used for power transmission (such as for buss lines) is .577 amps.
Here is a link to a handy wire chart from the Handbook of Electronic Tables and Formulas for American Wire Gauge. Other references vary a little, but this will get you in the ballpark on current capacities for different wire sizes. http://www.powerstream.com/Wire_Size.htm
It is best to use heavy enough wire to insure our circuit breakers will operate. If your 5 amp power supply trips quickly enough on the 24 guage wire, you may get by using it. But to be sure you’re safe, you should probably use heavier cable or you may get overheating under shorted conditions.
Try the quarter test, if the dcc command station kicks off your good to go if not simple run the bus wire.[:)]
I agree with the others. With three blocks there are really already 3 x 24 gauge wires feeding the layout. If the wires don’t get warm and if a short on the rails trips the DCC circuit breaker you should be good as is.
Even if it does get warm or doesn’t trip the breaker you don’t need a “BUS”. Just replace the three existing block feeds with a bit heavier wire like 20 or 18 gauge. Busses are for much larger layouts.
I once wasted a couple weekends redoing a small layout with 14 gauge wire. It could have been much more productive.
Ditto to the “If it ain’t broke, don’t fix it.” approach.
“Ditto to the “If it ain’t broke, don’t fix it.” approach.”
I’m a Master Electrician and an Electrical Engineer and I will emphatically tell you that advice like that could cause this fellow to have a fire!
Use the quarter test to be sure you are safe.
Agreed 100%. There could be a deadly difference between “ain’t broke” and “don’t know that it’s broke”.
Test test test!
(From another EE - RPI class of 82, master electrician, and former fire chief) Please put safety first.
Karl
PS: Three isolated blocks with a feed to each is still only ONE 24ga feeder at a time except when an engine spans a gap.