I am getting ready to convert to DCC.
My current HO layout is 24ft x 10ft consisting of 8 blocks, one of which is reversing. For each block, each rail is isolated. Speaker wire, probably 18 gauge, runs from each rail in each block to a dpdt switch for two cab control. Extra feeders are used where needed. For DCC do I need to change to a buss wire of a larger gauge and if so, how do I wire it without losing the ability to isolate each block if necessary? Do I need to replace all of the current wiring?
The easiest way is to just replace one of your cabs with the DCC power supply. The reversing section is the one that will give you trouble with this, though. For DCC, you'll need an auto reversing circuit in place of the reversing switch.
The 18 gauge wire should be good for the feeds, a layout your size, they should be less than 50 feet. If you do go the replacing wire route, just do that, replace the wire. Keep the separate feeds from the block switches to the track to isolate a section, especially when you need to troubleshoot the electrical system (notice I didn't say "if").
paxton58For DCC do I need to change to a buss wire of a larger gauge and if so, how do I wire it without losing the ability to isolate each block if necessary? Do I need to replace all of the current wiring?
Do NOT try to run a DC train and DCC train simultaneously using the manual block selection. That is a receipt for disaster.
With DCC you will be able to replace the manual DPDT for the reversing loop with an auto reversing unit.
I suggest you check out the Wiring For DCC site http://www.wiringfordcc.com/
in particular the section
http://www.wiringfordcc.com/track.htm#a16
Enjoy
Paul