Help needed for wiring size for droppers

[highlandchris]

My intention is that I shall be using solid core cable rated at 13amps ie 2.5mm twin and earth and i have stripped both conductors out of the grey insulation. These will be twisted together in a star formation for the main power bus. Im however uncertain as to what size cable for the dropper. I intend to have them at every two pieces of rail or maybe even every track piece. Each dropper could be up to 2.5 ft long.

I have a reel of two core flex cable sized at 0.5mm2 per core. I was thinking of using this and also to keep the two conductors in the white pvc insulation and only to break them out at the rail end just enough to go through baseboard and to leave enough for soldering. And at the power bus end sufficient to enable a join. I thought that using this method would keep the wiring more compact and therefore neater.

I would appreciate any thought members might have on these intentions

[Augustus Caesar]

Brian Lambert's excellent site under the DCC heading (page 1 of 2) has the following text...

 

"Having installed the DCC bus around the layout in suitable sized cable, there is now a need to connect the bus to the rails.  These wires are called 'Droppers'. This I recommend being carried out using 16/0.2mm or 7/0.2mm flexible wire in the same two insulation colours as the bus itself e.g. red/black or brown/blue etc. Note; I recommend if using the smaller 7/0.2mm wire then try to keep each dropper wires total length to around no more than 300mm.  Solid copper wire extension droppers from the rails to below baseboard can be used and then solder or use terminal block connectors that join the flexible dropper wires onto these extension droppers, where necessary cutting the extra length of the solid dropper wire off once all has been securely soldered.  However, you can solder the flexible dropper wires from the bus directly onto the rails if wished and is a better connection!"

 

Hope that helps... and of course taking a look at this site will offer much more for you in your future efforts.

 

http://www.brian-lambert.co.uk/

 

Just click the DCC link for the text above. He talks about many types of wiring such as the star you propose and more.

[RDS]

I also used 2.5mm solid cable, stripped from Household Ring Main T&E cable for my Bus.  For the droppers which are no more than 6" long, I have used 1mm Household lighting solid cable.  The droppers are connected generally to every other track piece.  In terms of keeping it neat underneath the board, I have used that white rectangular electrical conduit.