General Question about DCC & "DC" Block Wiring

[jwhitten]

 

I have been mulling over some stuff regarding "DCC" and "DC" Block Wiring...

On my layout I'm running DCC (NCE Powerhouse Pro) and plan to do so nearly exclusively.

However, I have also decided that I want to set up at least some "DC" blocks, primarily for power-routing-- really more for the ability to *remove* power from certain blocks (i.e. locomotive storage tracks, etc.) except for when I actually want to turn the power on for those blocks.

I know how to wire "DCC" and I know how to wire "DC" blocks, so neither of those are my question.

I was thinking about it some more this morning and realized that it would probably be nice to be able to switch in an actual "DC" throttle so I could run a non-decoder equipped loco for testing, or as a "visitor" or some such. So it looks like I'm using at least double-poled switching-- no problem there.

 

So for a layout that's larger than "just a couple of arm's lengths around" (i.e. requires actual effort and time to walk / run from one spot at the layout to another), what would be considered "best practices" these days?

 

Do people tie in their DC blocks to their DCC command system-- to use for power routing?

What about command consoles-- I'm guessing it would be nice to have one that's centralized, all in one place, but I can also see the advantage of having the block controls located near the actual blocks themselves. Also I can see some nice pluses to having the block controls available via "DCC". And I can see advantages to having them available via a computer I/O interface-- which I already have by virtue of the "DCC" rig...

So if I want to do all that-- would the best strategy be to set up block control using latching solenoids (for switching) or else their solid-state equivalent? And then everything else is just an momentary pushbutton or something to activate the solenoid / switching circuit?

Or is this just horrible overkill?

 

Thoughts??

 

john

 

[Vail and Southwestern RR]

Well, unless I'm missing something, I'm hearing horrible overkill! For blocks you want to kill, I would just put a switch on them, and kill them. I'd make that independent of what control system is running. I'd put the control near the block, since you will probably be there when you put the loco you want to kill on the block, anyway. As far as testing on DC, put in a switch to select either your DC system, or your DCC system. You don't want to have both powering the layout at the same time, anyway, so it doesn't need to be block based, just switch the whole layout. I am assuming here that you are talking about running one DC train at a time. If you are thinking of wiring multiple cabs, then you'd essentially have a cab that was DCC. BUT, you would want to ensure that if you are using DCC, all of the blocks must be on the DCC cab. At that point, you've wired a DC layout, and added DCC to it. And probably made things a lot more complex than you will ever use, and lost one of the advantages of DCC, namely, easier wiring.

[Phoebe Vet]

While it is not imposible, it is dangerous to mix DC & DCC on the same layout.  If they ever get accidentally cross circuited you are going to fry something expensive.

You can turn off a block in DCC just as you can in DC with a simple switch.

[retsignalmtr]

Using double pole, double throw, center off switches would be a good idea if you want to run DC occasionally or to isolate a section of track. Using a DPDT switch with the DCC mains enables you to run the entire layout DCC or DC. We do this on my clubs layout and we can run DC and DCC at the same time (different tracks though).

[rrinker]

 Maybe overkill, but you definitely do not want even the SLIGHTEST chance of mixing and matching DC and DCC - you WILL fry something if you do - that includes simply running the gaps between a block set to DC and one set to DCC. Best way I cna see to go about this is, if you just have one DCC power district, use a DPDT CENTER OFF (that way there's no chance of make-before-break contacts connectign the DC and DCC) at the main bus to switch between DCC and DC power. If you have multiple power disticts you'll probably have to tap in downstream of each one because they usually don't work on DC. Same with autoreversers. You can make one big switchover by using relays (I'd use 3PDT relays - see why in a second) at each power district with the coils all controlled by a master DC/DCC switch. If DCC is the more common, set it so relay coils WITHOUT power connects the DCC, and when the coils pull up, those contacts are used for DC. The extra relay contacts? To power some sort of indicator light or LED to indicate ALL blocks have switched from one to the other. Don't just trust that the relays will work when you flip the switch - maybe 5 do and the 6th one fails, so you merrily run a train around thinking everything's on DC, and then you cross that gap to the 6th section and - POOF.

                                                 --Randy

[Phoebe Vet]

Sorry, I  got interrupted.

The safest way to use both DC & DCC is to terminate the layout power buss at a socket and use it to plug one system or the other into the entire layout.  That way it is never possible to have them both connected an the same time.

I don't use your system so I don't know it's capabilities, but most DCC systems can run ONE DC train while running multiple DCC trains.  If you do that do not leave the DC train on the layout when it is not running, it will overheat.

[CSX Robert]

If you want DC and DCC to co-exist on the same layout, take look at the Lenz LT100 Analog Protection Module.

[jwhitten]

 In reading through the replies, I'm hearing loud and clear that you don't want to even run the risk of DCC and DC meeting up anywhere. So okay, I don't mind losing the "DC Cab" element (though the show was nice).

Which means I'm back to my original assessment that it would be nice to divide the layout up into switched blocks to permit better power management of the strictly DCC system.

My goal is to be able to shut down sections of the layout, organized into logical sections by function or junction or something similarly useful.

I like Randy's suggestion of using relays / switching with an extra pole to provide for a feedback mechanism, which could be used to light an indicator, or else a 'sense' line back to an electronic control system.

 

My thought of using DC was not so much to run the layout on, but more to work on (or play with) locos before I put decoders in them. I don't have an exact count, but I'd guestimate that perhaps maybe 30-35-ish locos, out of maybe 150-200 have decoders in them.  Probably half of the remaining will get eventually upgraded. The rest will probably live out the rest of their lives never knowing the joy of being DCC-enabled (or out of the box, for that matter)

 

thanks for the replies and feedback-- it was useful!

John

[fender777]

So as I am knew to DCC.I am learning as much as possible.But if you have your layout wired for DCC it is not a good idea to leave non DCC trains on the track like a spur.But one can run Some DC traian on DCC.

[Phoebe Vet]

fender777

So as I am knew to DCC.I am learning as much as possible.But if you have your layout wired for DCC it is not a good idea to leave non DCC trains on the track like a spur.But one can run Some DC traian on DCC.

It is not a good idea to leave DC trains parked on a POWERED DCC track.  A simple switch that turns the power off to the spur is all that is needed.  If your system supports it you can run ONE DC train at a time on the DCC track.