# DCC and wiring my new layout



## xbartx (4 mo ago)

I’m a novice here and looking for advice or suggestions on my small layout.
The picture is a photo merge of a couple pictures I took and me drawing in some still to be completed track ( I would guess it will total less than 60 ft of track).
This is a HOn3 layout is 4 x 8” in size with 8 turnouts and a turntable. The turnouts will be powered by slow switch machines. The turntable is powered and has a track revering feature.
I have quite a bit of older Digitrax equipment that was brand new and never installed, it is a Super Railroad Empire Builder starter set and came with a lot of extras, including some DS54 stationary decoders.

I only have one DCC equipped engine at the moment and can’t image running a lot of engines on this small of layout. Will a single block be an issue? Can I run a simple 16 gauge wire of about 25’ be used for the main track bus and 22 gauge wire for feeders?
Any other thoughts or comments would be appreciated.

-Brad


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## OilValleyRy (Oct 3, 2021)

For the bus, you could do just an inverted C shape, from the “rear” turnout sour area, following the mainline around but spaced in a few inches, over to that spur area in the front left. Feeders can tap off as needed due to turnouts etc. 

Technically one block would suffice. BUT you’ll need some sort of reverser for the TT.


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## xbartx (4 mo ago)

OilValleyRy said:


> For the bus, you could do just an inverted C shape, from the “rear” turnout sour area, following the mainline around but spaced in a few inches, over to that spur area in the front left. Feeders can tap off as needed due to turnouts etc.
> 
> Technically one block would suffice. BUT you’ll need some sort of reverser for the TT.


Thanks, 
The turntable instructions say that it has auto track power reversing capability, is that all I should need or do I need something more?


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## Conductorkev (Nov 5, 2021)

xbartx said:


> Thanks,
> The turntable instructions say that it has auto track power reversing capability, is that all I should need or do I need something more?



Is it atlas?

My atlas tt that had that was fine just follow the instructions of how to wire the leas tracks going to the tt. For power I just hook up a old dc power pack and that controlled it.


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## xbartx (4 mo ago)

Conductorkev said:


> Is it atlas?
> 
> My atlas tt that had that was fine just follow the instructions of how to wire the leas tracks going to the tt. For power I just hook up a old dc power pack and that controlled it.


No, it is not an Atlas. The turntable controller, track selector and motor _is a PTC Model III Programmable Turntable Indexing System_ from New York Railway Supply, Inc. and it has it's own power supply for the stepper motor.


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## Conductorkev (Nov 5, 2021)

xbartx said:


> No, it is not an Atlas. The turntable controller, track selector and motor _is a PTC Model III Programmable Turntable Indexing System_ from New York Railway Supply, Inc. and it has it's own power supply for the stepper motor.



Well have it wired and before trying use a volt meter using a track that's I'm coming have one on one side of the incoming track then the other side on the bridge that would get opposite polarity. Then turn the bridge 180° so the track is the opposite and test to see if it changed.

Now if it doesn't match do another check by shorting ig out used a car yhet has metal wheel (no engine or anything with power pickups) drive it on the bridge from yge lead to it see if it shorts out and then reverses polarity. This test I'd to see If there is a autoreverse unit built in.


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## DonR (Oct 18, 2012)

The wiring for your layout is quite simple as
Oilvalley has written. You just need a track
drop every 6 feet or so to your DCC bus.

You will need a DC power source for your
Tortoise turnout motors. The turntable motor
may also require DC, You can use an
old Power pack or an old wall wart. Look on
it's label for specs...but must have
an output of around 12 volts DC.

You can use the stationary DCC decoders
to control turnouts. Check the decoder manual
to see if they can switch the DC needed by
the Tortoises.

You state that the turntable has built in
reverse control. Thus, you do not need
any special wiring beyond what is
specified by the turntable manual. 

Don


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## Lemonhawk (Sep 24, 2013)

16 gauge wire is plenty big enough for a track buss on your layout, Keep in mind that track bus's should not circle around and be connected to the start, they an open ended bus. Essentially one bus from you controller goes off to the right and one goes off to the left and they do not meet and connect together! So the bus is probably half the length your thinking about.


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## OilValleyRy (Oct 3, 2021)

What Lemonhawk said. 
At those dead ends btw, you can use crimp connectors to reduce wire gauge, so the bus line actually ends with a pair of feeders, rather than wire nuts or wagos etc.


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## Magic (Jan 28, 2014)

Don't have any additional advice but that looks like it's going to be a nice layout.
Your off to a good start for a novice ( ❔ ), keep up the good work and have fun.

Magic


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## xbartx (4 mo ago)

Lemonhawk said:


> 16 gauge wire is plenty big enough for a track buss on your layout, Keep in mind that track bus's should not circle around and be connected to the start, they an open ended bus. Essentially one bus from you controller goes off to the right and one goes off to the left and they do not meet and connect together! So the bus is probably half the length your thinking about.


This is what I mocked up for the bus, does it look about right. I do have feeder wires spaced out on the layout and all of the turnouts now have feeders soldered to them. Can the 8 turnout motors be powered by the main bus? 

-Brad


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## xbartx (4 mo ago)

I just read why I should have separate power for the turnout motors, so a short there doesn't effect the rest of the system.


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## wvgca (Jan 21, 2013)

you -may- need snubbers, depending on your layout size ... easy to put on, just one on each end, if needed, just needed if you layout does strange or funny stuff ...
i had a 15 foot by 16 foot, and didn;t need them


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## CTValleyRR (Jul 26, 2014)

I'm the contrarian here, and my personal opinion is that people grossly overengineer their power circuits. That layout is a 4x8, so you're probably worrying needlessly about a track bus. I have run many a 4x8 layout, and even an 8x8 one, on a single pair of AWG22 feeders coming off the DCC command station. Put one set of feeders on each end of your oval, and one pair to each of the turntable tracks. That's probably all you need for a layout that size.

For the turnout motors, if you're operating them via the DCC system, then yes, they need to be connected to the track bus; otherwise, you will need a separate circuit (personally, that would be my recommendation).


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## xbartx (4 mo ago)

CTValleyRR said:


> I'm the contrarian here, and my personal opinion is that people grossly overengineer their power circuits. That layout is a 4x8, so you're probably worrying needlessly about a track bus. I have run many a 4x8 layout, and even an 8x8 one, on a single pair of AWG22 feeders coming off the DCC command station. Put one set of feeders on each end of your oval, and one pair to each of the turntable tracks. That's probably all you need for a layout that size.
> 
> For the turnout motors, if you're operating them via the DCC system, then yes, they need to be connected to the track bus; otherwise, you will need a separate circuit (personally, that would be my recommendation).


I'm reusing older turnouts that are reworked to be DCC friendly with the frog rails isolated and thus needing feeders to each turnout.


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## DonR (Oct 18, 2012)

DCC friendly is a marketing term and does
not describe anything meaningfull.
What modification was made on the 'older' turnouts?
If the frog was powered and the frog rails
are isolated from the powered frog you
need only use regular metal joiners to adjacent track.
If the frog rails are not isolated from the frog you should
use insulated joiners to adjacent track. 
If the frog was powered was a connection made to
it's own running rails? If so,
no special feed require to turnout track. The turnout
motor should be powered by a separate power
source unless it is fed power by a DCC stationary
decoder. See the decoder manual for wiring.

Don


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## xbartx (4 mo ago)

DonR said:


> DCC friendly is a marketing term and does
> not describe anything meaningfull.
> What modification was made on the 'older' turnouts?
> If the frog was powered and the frog rails
> ...


Don,
This is how I have them wired.


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## DonR (Oct 18, 2012)

You have a powered frog. The frog rails, as you indicate,
do need to use insulated joiners since their polarity will change
with the points. Normally, the stock rails
(Left of the frog) usually get their power from adjacent
rails. You may also power them as you indicate with
the blue and green marks assuming that adjacent
rails are polarized the same as your blue & green
marks.

Don


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## Lemonhawk (Sep 24, 2013)

Why does the Bus wire follow the track? Remember start at the controller and take one bus to the left and one bus to the right. The feeders feed all the nearest track. There is no rule that says the bus has to follow the track around. This will keep your bus wires much shorter. Assuming the controller is in the lower right. I would run one bus to the right ending around the turnouts at the top middle, another bus going to the left and ending around the curve on the top left. I would run a separate bus to the turntable area. All three can be connected together at the controller or you could use switches to turn off/on the bus to help isolate problems or use DCC track circuit breakers. Feeders can be 2 to 3ft in length so if possible keep the bus inboard to save wire length. I like terminal barrier strips rather than crimp connectors. Makes it easier to stick the probes of a meter on. A 4 terminal barrier strip is ideal at every place you want to run feeders off the bus. terminal one is the left rail feeder with shorting bars to terminal 2, which is the left rail in and out. Terminal 3 is the right rail with shorting bars to terminal 4 for the feeders. I use open ended lugs crimped to the all the wires going to the terminal barrier strip. As mentioned above you could easily just have a bus to each end of the layout with one or 2 feeders going to the track there, and another bus to the turntable area. Big box store have 16 gauge wire as it common for trailers to use the gauge. Terminal barriers can be had on Amazon along with shorting bars that short adjacent barriers. Even the big box stores have crimp tool and lug kits. Mark the wires! You will be amazed at how quickly you forget what all those wires go to. There are zip ties that have tabs on them to write on, or where you mount the terminal barrier strips mark on the wood what the wire is.


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## CTValleyRR (Jul 26, 2014)

xbartx said:


> I'm reusing older turnouts that are reworked to be DCC friendly with the frog rails isolated and thus needing feeders to each turnout.


That still doesn't really change the truth of what I said. Add some additional feeders to the isolated legs, but keep it as simple as possible. I would wire it as Lemonhawk suggests above. Maybe look at a frog juicer for those long, isolated frog rails.


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