Isolating a sidind using DCC

[Billm10454]

I want to isolate a siding. I am using DCC. Do I have to gap both rails or can I just gap one?

[OldTimer]

You may do either.  If you:
1.  just want to turn off the power to the siding, you can gap one rail and bridge that gap with a SPST (single pole, single throw) switch.  This is an on-off switch like a light switch.

2.  want to totally isolate the siding, you can gap both rails and bridge each gap with one pole of a DPST (double pole, single throw) switch.  This is like two on-off switches ganged together.

3.  want to make the siding multi-functional (main line or programming track, for example), as well as isolate it, you willl need to gap both rails and use a DPDT (double pole, double throw) center-off switch to control the input to the siding.  The two center contacts connect to the siding, the two contacts on one end of the switch connect to the programming outputs and the other two connect to the track power.  Make sure that the polarity matches.

If you've never wired a double pole toggle switch, you may not know that the center terminal connects to the terminal opposite the way the toggle handle points.  You can find mini-toggles with solder terminals.  If you don't solder, you can find larger toggles with screw terminals.  For option 1 above you could also use an Atlas Connector (three SPST switches in a single package).  Hope this helps.

[Billm10454]

Thanks for the response OldTimer

[Doneldon]

OT -

Make certain that your DPST switch has an actual middle position with both feeders off.  This is called a break before make switch.  Most DPST switches work this way but a few have an instant when both sets of terminals are bridged and you can have troubles with that arrangement.
                                                                            -- D

[jward]

other than the use of larger wire sizes for dcc, you can wire your layout the same way you would for dc and it would work well. in fact, that is what i do.

you'r wire an isolated siding through a block switch the same way you'd do it for dc. in fact, having your dcc layout divided into blocks has several advantages:
1. you can isolate the section of track you are working on during maintainence, and still have trains running on the rest of the layout.
2. short circuits can be quickly and easily isolated simply by turning off one block at a time until the short goes away.
3. if you should ever decide to go back to dc, your layout is already wired for it an example: your dcc unit goes on the blink and needs to be replaced. you can substitute a dc power pack and keep running trains until you can replace you dcc command station.....