wire gauge

[rrinker]

 Not anywhere near accurate due to the variable audio frequency, but assuming 8 ohm speaker impedence, you get 5 amps if putting out the full 200 watts. Assuming the amp can drive that much - 200 watt speakers with a 50 watt amp is ok, 50 watt speakers with a 200 watt amp is not ok.

P(watts)=I^2 x R, so I^2 = 200/8 = 25, I=5.

not totally accurate with audio frequencies and speakers with crossovers and so forth, but good enough for this discussion. The other factor is voltage. When you start with 120V and drop to 115V over the wire run, it's not usually a big deal. When you start with 15V and drop to 13V it's noticeable. The voltage on speaker cables is uaully somewhere in between - a tube amp can put out a pretty high voltage to get that watt rating, so a couple of volts drop won't noticeably affect the volume level - especially when both speakers have the same length of wire (which is a usual recommendation, even if one speaker is 10 feet from the amp and the other is 40, you should use 40 feet of wire with both speakers - specifically to keep the level equal with the same losses in the cable. When i still had audio gear, I just took a spool of wire and looped it back on itself, and cut it exactly in the middle.).

                             --Randy

 

[LLOYD]

ok, than you all for your replies.

[floridaflyer]

Agree with Randy on the use of stranded wire for the buss. I use #16 also on a 21'X8 layout. I use #22 solid wire for the track feeders, the single wire is easier for me to form to the rail  and solder.  

[BigDaddy]

The longer your layout (and the bus) the more voltage may drop over distance.  That's one issue.  The second is that your DCC system should, via circuit breaker or command station, turn off, if there is a short.  If it doesn't turn off, things get hot and the smoke may escape from your layout.  That may lead to a catastrophic release of smoke from the basement and the whole house.

Here are some guidelines for using smaller than 14 ga wire, on page 33

http://atsf93.qstation.org/Wiring.pdf

[selector]

In the layout I had for the longest time, I used 16 gauge speaker wire, the flexible stranded stuff with clear plastic insulation that comes in 20' lengths.  Worked perfectly well since it was designed to withstand the demands of 200 Watt speakers.  I don't know what the amperage would have been, but 4-8 amps is probably not an unreasonable guess....Randy?

I have only found decent doorbell wire in the 100' spools I can get at what used to be Radio Shack locally.  It involves stripping away the white insulation, but I can get four tiny 22 gauge insulated solid copper wires in that wrapping.  It's very easy to manipulate, to strip, and to solder to the insides of my rails.

[rrinker]

 The key is stranded vs solid - it's MUCH easier to work with the heavier wire in stranded vs solid. My previous around the bedroom walls layout used #14 stranded for the bus, no issues. For the main line I had 2 runs, one in each direction, which put the longest distance at about 25 feet. On the layout before that I used #12 stranded because that 8x12 was inteded to be just the starting point of a layout that was going to fill a large basement. I neither case were there any issue handling the wire. I understand why they use solid in house wiring, but one of my least favorite drydgery jobs, which I need to do on this house too it seems, is replacing the old worn out wall outlets. I always rejoice when I hit the outlet int he room that is the end of a run, because then I only have one set of wires to deal with. The intermediate ones, with tweo sets of wires, so painful getting it stuffed back in the box.

                            --Randy

 

[UNCLEBUTCH]

I used 12ga for buss,that's what I had on hand. I would not suggest it. Way too stiff and hard to work with.  14 or 16 is better.

I use 20/22 for feeders, and for atime for buss,but because it was all short pieces [recycled]  it looked like a bird nest, but worked fine.

 If I had to do it again; I would dip into the coffee can and '' buy'' a smaller bus[wire]

[doctorwayne]

I use a dual bus system...

...and this is pretty much all of the major wiring...

There's about 200' of mainline above that jumble of plywood, and the power source is a foot-or-so behind the camera.

Since the latter photo was taken, I have added a couple of supplementary feeders for an additional 65' of mainline and another staging yard.

Operation is DC.  Sorry, I did try, but resistance was futile and I couldn't restrain myself.   No disrespect intended to the O.P. or the other respondents.

Wayne

 

[richhotrain]

tstage

On my 4 x 8 I used a 14g bus and 22g feeders.

And, on my 25' x 42' layout, I also use 14g bus and 22g feeders.

Rich

[tstage]

Lloyd,

It depends on the size of your layout.  A simple 4 x 8 "oval" could easily be powered by just two 22g wires - even with a couple of turnouts thrown in.  For best results, however, a 16g power bus or heavy is generally recommended.

It's your choice as to whether you want to use solid or stranded wire for your bus.  For track feeders you'll want stranded for the flexibility.  On my 4 x 8 I used a 14g bus and 22g feeders.

I also chose to use IDCs (insulation-displacement connectors) with 18ga stranded as a go-between my bus and my track feeders.  They worked great for me but not everyone on here likes them.  You'll get strong opinions either way.

Tom

[carl425]

The choice of wire size is based on the current draw of your locomotives and the length of the run.  Most DCC users run bus lines of #12, #14 or #16. Ignoring cost and stiffness, there is no "too heavy".

Here's a good explaination:

http://www.dccwiki.com/Wire_Sizes_and_Spacing

Here's another:

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

[LLOYD]

I'm finally switching to DCC from DC somewhat using a DPDT switch.  My trains run fine on DC but do I need to beef up my buss wiring from 22 gauge to a heavier gauge? Also is 19 gauge wire, (which I have left over from a spa installation) to heavy?