Wiring a Layout for DCC and DC

[GatorCub]

In the July, 2011 issue there is an article "How to wire a layout for two-train operation"

By Neil Besougloff. It got me to thinking if this method of cab-control wiring could be used to run a layout using DC or DCC. I have 7 locomotives that are not equipped with DCC modules and 3 that are. Is it possible to connect one side of the SPDT toggle to my regular DC powerpack and the other side to my Digitrax DCS 50? I already have my track electrically isolated into blocks. Then by toggling to one side or the other I could run 1 of the DC locomotives OR a couple of DCC controlled units. Is it feasible?

[Truck]

I smell smoke!!

[tomikawaTT]

You could wire a layout for 2-cab control, one DC cab and one DCC base station.

Then, in a careless moment, you could fry the motor(s) of one or several DC locomotives by inadvertently feeding them DCC.

Unless you have an unlimited source of replacement motors, my advice can be boiled down to a Noo Yawker's favorite word:

FUGGEDABOUDIT!!!

Chuck (Native New Yorker modeling Central Japan in September, 1964 - analog DC, MZL system)

[Rexrichard]

I belong to a model railroad club that runs DC and DCC on the same layout.  The layout is 16' X 34' portable layout.  Each module is 30" wide.  There are three main lines encircling the layout.  Each main line and the associated side tracks can be individually switched between DC and DCC.  Such an arrangement satisfies the needs of the club members, some of whom run DC locomotives and some who run DCC locomotives.  I have been a member of the club for three years and in this time we have taken the layout to many public events and run both DC and DCC locomotives on the track at the same time.  We have never had a problem  The layout was designed and built before I joined the club and the wiring was designed and built by an electrical engineer.  

[richg1998]

A few years ago when our club started out with DCC we would do that. We had 14 blocks and 4 throttle DC capability and had not changed wiring at that time. One time, a couple people where gabbing, playing with trains, and a DC loco ran into a block controlled by our NCE 5 amp Power Pro and the NCE controller smoked before they realized what had happened.

But the choice is yours. Will you be operating your trains or just playing with trains? Your mileage may vary.

Rich

[rrinker]

 You CAN do that but it is very easy to make a mistake and fry some stuff. The common rail wiring is part of that. But even if all toggles were DPDT, it's too easy to drive past a block boundary which will tie the DCC and DC systems together, via the decoder in a DCC loco: poof!

 It is best not to run DC and DCC at the same time, instead use a single top level DPDT center-off toggle - so the entire layout is EITHER DC or DCC, never both. No chance of a costly mistake that way. 

                --Randy

 

[jrbernier]

  There are issues with running a club layout in 'dual mode':

• If it is a modular display layout with very little chance if crossing over  from a DC main  to a DCC main, it will work.  The chance of having a disaster is small, but it is there.
• If you have a large club layout with lots of single track and passing sidings, the chances of screwing up are much higher!
• If you are going to mix DC & DCC, do not use 'common rail' blocks - got with dual gaps and DPDT toggles - you want to make sure you have no 'sneak' loop back routes...

  The above said, my layout was wired for DC cab control.  I just replaced one of the power packs with my DCC system and flipped the toggles.  Of course I was usually running one engine/consist by myself and there were no conflicts.  The LHS converted their 'test track' to dual mode and kept whacking decoders because they would overrun the 'gap' .  Usually a 'reset' of the decoder would resolve the problem - but they eventually built separate tracks for DC and DCC testing/demo.   In my case, I eventually pulled all three DC panels and the wiring and replaced it all with #14 bus wires and 4 power districts - the layout is 100% DCC...

Jim 

[MisterBeasley]

Get 7 decoders and wire up those DC engines for DCC.

"Dual-DC-DCC" is a distraction, and a potentially dangerous one at that.  If you're in your own "transition era" between DC and DCC, just bite the bullet and git 'er done.

[GatorCub]

Thanks guys,

I appreciate all the expert advice. Sounds like too much of a potential disaster to wire for both. I guess I'll just start DCC equipping those other locomotives as funds become available. 

[Cannoli]

You mentioned you have a Digitrax system, I thought I recall reading that a Digitrax DCC system can run 1 DC loco using address 0? I don't personally own a Digitrax, system to confirm but some quick searching on the DCS 50 via Google and Digitrax's site shows that it should be possible and will save you the risk and headaches of accidentally frying a loco if a switch is not set properly using the dual wiring method.

[GatorCub]

Hey Cannoli,

 

Yes, that's what my manual says. But I read somewhere that it's risky and could damage the DC engine. 

Guess I'll just save my pennies and convert to DCC.

Thanks for the info.

 

[jalajoie]

GatorCub

Hey Cannoli,

Yes, that's what my manual says. But I read somewhere that it's risky and could damage the DC engine. 

Guess I'll just save my pennies and convert to DCC.

Thanks for the info. 

Yes I read all kind of horror stories about this urban legend.

 To reassure you, we have a member that has never installed a decoder in his fleet and has been running his locos on a Digitrax DCC system for the past 10 years without any problem to his locos.

  

[jeffrey-wimberly]

GatorCub

Yes, that's what my manual says. But I read somewhere that it's risky and could damage the DC engine. 

Guess I'll just save my pennies and convert to DCC.

It WILL damage the DC loco if you leave it sitting on a DCC powered track for an extended period. As for running DCC and DC on same layout, I had my last layout set up for that. It was divided into 16 blocks with each block on it's own DPDT switch. Up for DCC, down for DC. I could have DCC locos running on the mains and at the same time have the passing siding and spurs switched to DC and have a couple of DC switchers moving cars around. On a couple of occasions I had a loco on DC track come into contact with DCC track. The world didn't end, the DCC controller didn't blow out. I saw the short indication on the DCS50 and flipped that block to DC. The short went away and I stopped the DCC loco that was heading for that block. I backed the DC loco back onto the siding then switched the other block back to DCC and resumed operations. As an added precaution the DC pack and the DCS50 were plugged into individually switched outlets that could be turned off separately or together. I also had a consist of two DC locos that I would run with the DCS50 on address zero. As long as the locos were running the motors wouldn't heat up. But if they were allowed to sit on DCC track the motors would heat up. In an experiment with two Athearn motors I left them to DCC powered track to see how long it would take to burn them out. One expired in just under two hours, the other lasted over six hours.

[jalajoie]

I remember when you made that experiment Jeffrey, I would say 2 hours is an extended period of time.

[jeffrey-wimberly]

jalajoie

I remember when you made that experiment Jeffrey, I would say 2 hours is an extended period of time.

And that was the time it took for the motor to burn out. It would likely have melted the shell above the motor far earlier. I didn't have the shells on them during the experiment.

[rrinker]

 Of course, it depends on the motor, Athearn motors are quite robust, a more delicate type might not last even 2 hours. But that's STANDING STILL. Moving is completely different, and the higher the throttle the less of an issue it is as there is less and less time that the ucrrent is int he opposite direction. Some locos run better on address 0 than others, Only coreless motors will be pretty much instantly damaged, but you won;t find one of those in any Atlas, Athearn, or Bachmann loco unless someone remotored it before you aquired it. And they will be tough to control unless your DC power pack is a transistor one.

 Since you can get a top quality excellent runnign decoder for $12,t here's little excuse. Use address 0 for now while you save up the $120 for the 10 pack of NCE D13SRJ decoders, and then convert 10 of your locos. Now you have 10 operating properly on DCC< plus whatever sound units you had, and repeat if you have more to convert. One does not need every loco on the shelf converted TODAY. That's when it gets expensive.

              --Randy

 

[galaxy]

Hi and

I will just toss my two cents in for backing up your decision NOT to try to run both.

I have the Bachmann EZ Command DCC system, which says I can run a DC loco on address 10.

The problem is that I don't trust it or myself to not fry something as I can fry a toaster by putting a slice of bread in it and pushing the lever down!!

When I got back into the hobby 6 years ago I jumped into HO {from O and N as a teen} and started with DC engines. THen I read about this fantastic thing called DCC and decided to go there for ease of wiring my layout and running trains.

I got rid of my DC locos and have bought only DCC equiped locos since I decided to go DCC. That way I don't run a risk of frying anything as I never mix the two. The DC locos I had were not that important to me to convert as I don't know how and were really to cheap to pay someone to do it for me. ANd I got better replacements for them by buying DCC equiped ones to use.

So I vote for NEVER mixing the two or trying for a dual-wired layout. It may work for, and be necessary for Clubs, but for your own layout either be IN the DCC game or OUT of it.

Other opinions may vary

[pjinoz]

MRC Tech6 claims to do both DC and DCC controll with sound,saw the add on back of MRR mag,issueMarch 2010. Popped the question in the forum if anyone has had bought that unit.I too like to use both DC and DCC engines.On Tech 6 is also a "Dual" mode according to the discription. I think You can Google up their site and read about it

[rrinker]

 The Tech 6 is one or the other. You flip back and forth with a mode selection, in DC mode it puts DC on the track, in DCC mode it puts DCC on the track.

 I've made my opion on this product known several times: avoid it. Just buy a real DCC system, and get more DCC features, and if you still have a lot of unconverted locos to run, connect the DCC system to the layout via a DPDT center off toggle switch, and conenct your existign DC power pack to one side, and the DCC system to the other. FLip teh switch one way, and you rlayotu is DC< flip it the other, and it's DCC. Eventually you'll convert your existing locos and no longe rneed the DC mode.

 ANd converting need not be expensive, at least in HO. the NCE D13SRJ decoder is a very good decoder and if you buy a 10 pack the cost comes out to $12 each. Expensive to convert to DCC? Hogwash!

                               --Randy