Wiring the BUS

Bus wires the bigger the better (within reason) Droppers of course can be smaller. So for a 5amp system ideally you should have 7-10 amp cabling as a bus.
Some people may think this is overkill, but for the sake of saving pennies on cable I'd rather have the capacity.

I think the BUS is very important. I have seen fragile BUS wires that contribute to the bad functioning of some layouts.

This is what I use. Perhaps a little OTT, but I am vvery happy with the result and I have no voltage drop over the layout.

Conductivity problems between loco and track and the track pieces themselves are what plague a layout and give quite a bit of grief. I'll feel better knowing that the signal is being properly conducted to all corners of the layout.

I have soldered feeder wires directly to each piece of flexi-track. This will later help with block control should I implement it. I grind down a patch under the rail - removing all oxidation. I tin and then solder on a set of wires.

I lay the track with two feeders adjacent to each other, preventing too many connections to the DCC BUS.



All my red wires are to the front of the layout. Keep it simple - no reversing modules are needed anywhere on the layout except at each return loop on either end of the dog-bone. As a 'red' rail will bend around and touch a 'black' rail, the reversing look sorts that out.

I join all track with insulated rail joiners.

I group feeders together and connect them to the DCC BUS using this type of connector:



The DCC BUS itself is low resistance (6mm²) speaker wire that should maintain a good DCC signal all around the track. I use a continuous wire from one side to the other. That is why these connectors come in handy - they allow me to add feeders wherever I want without cutting the copper. I just trim back a bit of the insulating plastic, drop in the wire under the screw, replace the screw, tighten and add the cap that prevents splitting.



The DCC BUS is just under 20 metres long and it works fine with my Lenz LZV100 command station roughly in the middle. If I need to add a booster later, I can either split the Main DCC BUS into two sections or add another under the baseboards.



Here is my DCC RRampMeter Showing a nice and steady 16 volts at my command station:

It sometimes flutters to 15.9, but doesn't go below that.

On the other side of the layout:

This photo is taken about 10 meters away (along the track). It shows that my oversize BUS wires and feeders do the job perfectly. No voltage drop over this distance.

To check the layout with a load, I added a load to the RRampMeter in the form of a halogen bulb connected to the output terminals. The bulb had a current draw of 1.75 amps. The RRampMeter measured 15.2 volts DCC at the command station and 15.2 volts at the same distant point 10 meters down the track. So again the BUS does it's job perfectly.

That's a new one Doug I've never seen that type of connector before, what's it called...............in English.
In south Africa we used bare copper earth wire about 7mm dia as a bus, with a clearance of 70mm between bus wires there was never a problem. This is commonly used for house earth wire, and is cheap, due to high level of Electrical storms each house is wired with it's own RCD. If you use multi strand droppers, you don't even need to solder to the bus, without intervention they never come loose. Just wrap your colour coded (red or black) dropper end, suitably stripped around the bus ensuing a tight wrap-around. Naturally this type of bus is best suited to those using a rigid baseboard. IE non portable.
Here's another fallacy soldering your droppers underneath the rail is neater and better practice- total rubbish just solder to the outside of the rail, it gets covered with ballast anyway, so why make a rod for your own back. Just tin the end of the dropper, using the pliers make a small 90 degree turn and solder this to the side of the rail - a perfect connection every time, easy to change if needed.