DCC Bus power district

[bluesparky]

Hi, I'm just at the point where i'm about to start building my baseboard and then obviously start laying track with soldered droppers etc.

 The layout is going to be in my shed, which is in good condition, but I'm not sure how to apply the power districts to the layout.

 Is it better to break the layout up into areas (i.e. in chunks) or routes?
 

 I've got a Gaugemaster prodigy operating system with a power booster and individual trimmable RCDs for each district to come off it.

 It will be a running loops layout, with three main lines, shunting yard and fiddle yard. It's not quite as complicated as it sounds as I won't have time.

 

 

 I was going to do it on CODE 75 track but due to time constraints and also the help I'll be (gratefully receiving) it'll be on preset CODE 100 to make it easier for several people to lay track at once on the layout etc.

 

 SO, if the districts are split into the three main running lines, fiddle yard & shunting yard, then I guess only ONE will trip the RCD if there's a problem, making it easier to isolate and find the problem? 
Yet if I break the model railway up into chunks / areas / baseboard squares etc, then if an RCD goes or shorts, then it could be on any of the lines and make it harder to troubleshoot whilst bringing the whole layout to a standstill?

 

 By my own reckoning, does that mean running a seperate bus for each main line etc the most sensible option?
 

 As for point motors (i'm using under board Peco), do they run on the same bus, have their own? Have their own return? I can't find information that doesn't contradict something else? I appreciate the need for very precise records, labelled and colour coded cables and tidiness at all times (i'm looking forward to organising that bit!)

 Thank you

[Pete the Elaner]

Understanding how your own layout is wired is as important as how you do it, because if you do get any problems, you are able to find the fault.

 

I have 3 main lines on my layout; 2 double track & a single. I isolated these from each other & fed them each through a separate RCD. Because I work a little untidily, I occasionally have something short out one of the circuits & its breaker cuts in before the command station reacts, so only 1 line is affected.

Although my layout was always intended as a home layout, I have built it in small sections so I can work on each individually & move the whole thing should I ever want to move house. If I struggle to locate a power fault, I can remove the inter-board connectors & replace them 1 at a time to isolate the fault quickly.

 

I am sure there may be arguments for splitting the power (sub)districts by board rather than by line, but this is how I chose to do it & I have not had any problems with it.

[ColinK]

I too have split my layout into power districts by route; main line, branch line etc. It works great, especially with sound fitted locos. If we have a short on one route, the others keep running and when exhibiting nobody spots the problem. If it were no power districts, all the locos would stop and go quiet.

 

In practice, most shorts are caused by operator mistakes, so the operator of the line that has stopped can usually quickly spot and overcome the problem.

[Vonzack]

Hi bluesparky,

 

I think it's always better to split the layout up into routes or lines as ColinK says, on our layout we have Power Districts for Up Line / Down Line / Sidings and Accessories. Whichever split you choose, if you are going to run your points from Accessory decoders, I would recommend that these are run from one of the Power Districts or from the Main DCC Bus. The reason for this is that if one of your Power Districts shorts because you've run into a point set against the direction of travel, you can always still operate it without having to use the 'hand of god'.

 

It does mean that rather than one bus, you would be running several under the baseboards though.

 

Cheers, Mark.

[Junctionmad]

The only issue with route based power districts is it increases the amount of inter baseboard wiring ( and connectors for a movable layout )

 

I use base board based districts , so that only one DCC bus loops from baseboard to baseboard

 

It's not quite as functional as route based districts , but I could even break up the baseboard districts into route ones per baseboard at the issue of having a lot of cutoffs !

[Ron Ron Ron]

..... I've got a Gaugemaster prodigy operating system with a power booster and individual trimmable RCDs for each district to come off it.

 It will be a running loops layout, with three main lines, shunting yard and fiddle yard. It's not quite as complicated as it sounds as I won't have time.

 

I read that to say that you will have 2 boosters.

The main system booster (located along with the command station, inside the Prodigy base station) and an additional booster; plus the RCD's to provide sub-districts.

Is that correct?

If so, you have a further question beyond the provision for fault finding, or keeping the layout running when shorts occur.

That is to decide what parts of the layout each booster will power, as well as working out how the layout will be split into sub-districts.

 

With 2 boosters, it will be important to think about where the power demand will be coming from.

 

For example..... the case of a large loco depot with lots of locos "ticking over" on the juice, or a busy yard with a number of locos (both active and stationary) and shunting movements taking place; versus the mainlines with only 1 or 2 locos working on them at any time.

In this example, there will probably be a larger demand on the available system power from the yard or depot, so depending on how large that demand is, you might want to provide that part of the layout with its own booster and have the rest of the layout runs off the other booster, but split into sub-districts (for the obvious reasons).

 

Another example would be a very large layout, with long distances involved. 

In this example the 2 boosters (or more), might be better employed in a geographical layout, based on distance. The circuit breakers would still be able to divide the individual running lines up, within the respective power districts.

 

 

As for point motors (i'm using under board Peco), do they run on the same bus, have their own? Have their own return?.......

 

If the point motors are to be operated via DCC, then you will need accessory decoders to control them.

If you are already planning to sensibly divide the layout up in to power districts and sub-districts for short protection and fault finding; it would be logical to provide another power district, or power sub-district to operate all your ancillaries, such as accessory decoders and point motors.

That would indeed involve its own accessory power bus.

 

 

.

Edited November 22, 2017 by Ron Ron Ron

[DCB]

The smaller the chunks the better for fault location. To keep the show on the road wiring breakers by route should keep something moving but consider ways of isolating sections of track for fault testing, either switches or on portable layouts arrange the multipin plugs so you can isolate each baseboard in turn.   Faults are elusive and one which is only mildly annoying on a DC layout will render a DCC one unusable, Loose point blades and wheel backs brushing point blades are favorite breaker trippers, and my most elusive to date a Hornby Q1 where the wheel flange hit a displaced layshaft.on one specific track kink.

Watch for high power consumption in loco depots and carriage sidings with carriage lights on and sound equipped locos on shed.

A battery powered diesel for track testing and recovering stock from dead power regions is always a good idea. as its difficult to tweak track after you have drilled holes and  added droppers. 

[Izzy]

I'd be interested to know what the individual trimmablle RCD's are that you will be using with the PA2 system.  Are these different to the commonly available circuit breakers?

 

Thanks,

 

Izzy

[Alan Kettlewell]

Hi,

 

If it helps, I did mine like this. You might want to enlarge the picture to see I've based the districts on location on the layout. So the storage roads are in one district, station area in another and the scenic part on the other side is in the third district.

 

When setting this up I considered ease of setting it up ie the least amount of wiring, plus I made estimations about how much power might be consumed in each district. So far so good.

 

This is just the way I did it, I'm not saying it's right or better or worse than other options. You can read more on it on pages 2 and 3 of my layout thread shown below.

 

 

Cheers ... Alan

[bluesparky]

Hi all, thank you for the replies and responses - I've been mega-busy recently and unable to find the time even to type a thank you!

 The plan of a battery powered loco is a good one - off to ebay I go!

 Thanks for all of the plans and ideas, I'll slowly digest them and start work asap on the actual layout.

 It's going to be in my shed, so quite cold at the mo, but we're very much looking forward to getting started.

 I'll keep you posted on progress.

 Cheers,

 Mark

[Phil S]

Whilst my permanent loft layout is wired 'geographically' - ie  off-Stage Storage (lower level|), Barnstaple Junction,   'left'  and 'right' scenic sections, it largely corresponds to routes as well -  as the routes involved are single track, and apart from a test circuit, there is no continuous loop, Probability is <1 running train per sub section.

 

Each of my 4 power districts is fed via a PSX breaker, and has a RRampmeter monitoring current (typically 0.25A due to LED lighting etc ... peaking normally at just over an amp.  

 

In your case, with identifiable continuous running loops - each of these as a separate Sub (or power) district would seem logical BUT consider how a train moves from the MIDDLE loop to either side !!! .... Do they  cross on the level ??? DO THEY NEED TO BE 'Power Districts' - or would 'Sub Districts' (off the SAME POWER SUPPLY/dcc output do ??? )    

When I started loco currents were higher (Hornby Dublo, XO4 and bulb lighting) - now we have more efficient motors (and NEO magnets for older Hornby Dublo locos!!) and LED lighting.... so I can run my whole layout off 1 controller if I want (and that is available on the B position of my switches )

 

Perhaps more important is how you aid your fault-finding diagnostics with SUB-districts - isolatable areas off the same power bus - eg, in my case,the sidings or Platforms at Barnstaple can be disconnected with a LOCAL switch for each.   The same idea of intercepting the main-bus distribution applies to each of the other power districts.   When it gets down to the 'smaller areas' to find the fault, I find it easier to have it 'logically' and geographically confined to the area immediately in front of me - to look for the small piece of metal, or derailed item causing the short.

 

I also have LEDs wired by each switch on my (central) bus /power distribution panel: A row  of switches for each of : TRACK busses, Accessory Busses,  12-16AC bus and 12Vdc bus.   ( Vertically they are arranged for each of the Lower Storage Areas, Barnstaple (main station), and Left, and Right Scenic areas.)

 

The LED is on the 'far' (track) side of the switch - and will therefore light up if any power is present on that piece of (track) - even if the section is switched off (eg with a wheel bridging a gap) ... ideally  a 2-wire bi-colour LED ( or 2 LEDs placed in inverse parallel)  - so that polarity can be observed (eg if testing with a 9V battery at the track end), and both colours if ac/dcc)

 

As a power consumption guide, although I use 4 Roco Amplifiers (3.2A max each) in the loft ( replacing a ZTC511 + 1 5A booster) - 1 would do ! but the others came 'free' in the many digital start sets I bought initially 8-)  ... as they can each be used as boosters (pre Railcom)

I use Roco or Veissmann point motors which are low current - or power can be taken from the AC bus, rather than track - keeping the dcc current low.

 

For our multi-level Exhibition Portable H0 layout we use 1 Roco Amplifier (3.2A) supplying all of the 3 levels - so the 3x PSX each protect a SUBdistrict (same power suppl;y/dcc).   TrainTech CDU point modules are used powered from the dcc Accessory bus (replacing Lenz LS150s which needed a 16V ac bus as well) - and although they take current from the main dcc, they do not cause a power outage - and we regularly have 3 or more train running ( 1 or 2 on each level )  

 

When a train is running up the helix connecting the 3 levels together, probably only 1 or 2 other trains are left running.    

We do also have a totally independent 'test loop' for programming or which visitors can operate - this runs off a Roco Amplifier+Multimaus - and means that we always have a spare available, or that a train can be running whilst a problem is investigated.

 

For our 14m linear G Scale we have just the one section - with power connected only through the (code320) brass rails - Running from 1 Roco Amplifier /Z21 without a problem even with the power hungry LGB Allegra [4 motors] - unless it stalls against a buffer!! ...3A is adequate !   BUT in the garden with a slope we need a 5-8A supply due to the gradients and perhaps 5 locos with sound and lighting etc.... but it is only a single power section - as you get enough problems in a garden without having deliberately switched-off sections ! (And any switches would need to be 5-10A rated - I use WAGO lever-locked connectors so I could isolate the feeds without a screwdriver)