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power districts

3.7K views 12 replies 4 participants last post by  PAPPA.B  
#1 ·
Hi I'm looking into building a layout on three levels 2.4 x 7.2 overall . Lower level will be storage with 10 -15 tracks middle level will be a four track oval with some three/ four tracks storage tracks under the upper level which will be a terminus station
and goods yard .THE track plan is based on a smaller spaced Cyril Freezer which is only on two levels and is 2.1x 3.3 approx. A double track will connect the upper and middle levels whilst a single track will join the middle trackwork with the lower level.
I,m planning on using the NCE system as I already have the starter kit however I realize I will require a bigger 5amp controller plus boosters my thoughts are two but I,m really not sure .Would each power source (booster/control station) power a level ?
Or an area covering three levels spit into three over the 7.2 this seems complicated in regards to the bus wire. Will 5amps be sufficient at 7.2 with multiple tracks my intention is perhaps two cabs possibly three. Most of the time it will be just one cab.
AT moment this is all in my head the layout will be homed in a shed which is yet to be constructed that beginning this summer. The cost of this construction is considerable and a DCC system also, looking at £3,000 before even talking track and that's a
conservative estimate . Thus the need to make the right choices !
I have been searching for info on this can any one recommend a book or video which would guide me in the right direction . This project is aimed towards my retirement in just under four years time though by then I hope to have made some good progress
Many thanks for any help Jim
 
#2 ·
OK Jim but you are pessimistic on power, I use Roco Z21 and I run 8 tracks the draw of current is quite limited and I found I did not need a booster at all. I operate from a shed but it cost about £15,000 with the base and is inside 8m x 4m and double walled and double glazed which helps insulation a lot.

If you really need so much kit then buy a Z21 and minimise your requirements. I am sure Richard Johnson can put you right on this anyway.

Your big problem is getting the levels right. I have 2 levels and the one is 132mm above the other (height of a Metcalf viaduct) so using 12mm MDF/ply I have 120 mm to fit in the fiddle yard with access and its congested. So your lower level may need to be near 150 below the base above.

I also organised multiple access ways in the corner, by the entrance, in the middle, 3 levels gets difficult.

Gradients I use 1 in 30 maximum and really that is the limit I did a lot of tests so a 132 mm climb needs a ramp of 4 metres plus transition gradients, in fact going up is not a bother but coming down is the issue.

Dirt then gets in the way, I use a CMX cleaner which helps but times are you need to get in there with the hand of god to clean track and keep the loco wheels clean
You are 110 miles from me but welcome if you wanted to come and look! (I am near Exeter)

The gradient is on the left of Towcaster Adolphus Sq station a train going down
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The central access open shows the lower fiddle yard of 19 roads from the 4 track main line so 5 roads each except the inside which has 4
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This views gives an idea of the levels, with a third level on top could be difficult
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#3 · (Edited by Moderator)
Unless you are using automation, or having several friends round operating from multiple cabs, you will find it extremely difficult to run enough trains simultaneously to exceed 5 amps of power. I operate my layout using Traincontroller automation, so I'm able to run many more trains automatically than I could ever do manually (especially with grandchildren to be entertained!). I did try and see if there was a limit: I managed to get 14 going at one point (and several of these were consists of EMUs) but my Lenz 5-amp booster didn't blink.

However, with a large layout it's still a good idea to divide the layout into power districts if only to be able to track down unexpected short circuits. If, for example, you were to divide the layout into 3 distinct wiring sections each with their own bus, you could feed all 3 from the same booster but via suitably-rated on-off switches. So if you get an unexplained short circuit, you can switch out each section in turn till you narrow it down. You could also use circuit breakers for each rather than on-off switches. But that would mean a short in one section resulting in any trains in the other sections continuing to run. If you are normally the only operator, is that really desirable? With my layout, if I get a short circuit anywhere I want all trains to stop immediately so I can concentrate on the fault. The layout is divided into two halves electrically separate from each other, but powered from the single booster via on-off switches.

Having done it this way to start with, there's nothing to stop you upgrading in the future, replacing the on-off switches with their own booster if you find the power is required.

Of course you need to isolate both above and below at the changeover, so insulated rail above on both rails, and droppers from the rails must go to the correct bus wire to avoid bridging the gap.
 
#4 ·
Hi Kris Yes I do not know how much power I need I guessing most probably over doing things electrically not my forte . As for levels I will be using omega anolog point motors so the head room will depend on their depth which without digging them out is about 70mm so clearance plus that 180mm from level to level I'm talking off the top of my head without any actual proof something that was my first experiment whence the shed is constructed . The lower level would have some what a bigger access 300mm I realize this would need probable track descending twice around the shed though again I will experiment I was looking at a 1-50 which I think is doable but as said needs to experiment . The other issue to the incline
is my wish to have a Hornby Castle class and eight Hornby/Bachmann collett coaches climbing these. I will only really find the answers with some experiments but having an idea about the power will help! Thanks for reply jim
 
#5 ·
Thanks RFS How big is your layout? Most of the time it will probably only be me operating the layout but i'm reading things but not understanding . I didn't know how much voltage is lost over distance or multiple tracks if any . I'm aware that my NCE
starter can run three loco's but as there may be other things running from these units I was not sure how much this will affect the need. I am intending to have some form short protection via districts . Thankyou for you reply Jim
 
#6 ·
My layout is approx. 30ftx9ft on a single level. Basically 16 long storage roads on one side feeding 4 tracks into a main central station on the other. The main thing with the DCC bus is to use wire that is thick enough to eliminate voltage drop. I use 2.5mm wires from household twin-and-earth, and this stuff is easily obtainable from DIY stores. If you want to use multi-core then 32 x 0.2mm should be adequate for a layout of your size.

But the main area where voltage drop can be a problem is not the bus wire but the rails. Nickel Silver track is not a particularly good conductor of electricity and rail joiners even less so, especially if they become oxidised. The simple solution with DCC is to have a dropper feed on every piece of track. I know it can be a time-consuming task but you only need to do it once. With DCC it's not so much the voltage you need to worry about, but the fact that the DCC signal is superimposed on the track feed and it's essential that your wiring makes for a clean DCC signal. Hence the need for a good, solid bus wire plus droppers on each piece of track.
 
#7 ·
Kris Thank you for the invitation Yes Exeter just down the M5 not to far away I may take you up on that . As yet nothing set in stone but trying to get my head round the electrics hence books or videos .I have to dismantle Much Faffing not that there is that
much to dismantle i'm hoping to use the baseboards for the lower level . Gradients are indeed an issue my lower level will only be accessed from one end the other having a turntable to allow a loco run around. A CMX cleaner is on my purchase list at some
point . A lot to think about plenty of time though .Jim
 
#9 ·
Jim, I also echo RFS in that I have separate electrical sections exactly to isolate the shorts so this is a good idea, forgot how important this is as it works well.

Droppers are fine but you only really need them if you use electrofrog points I have no trouble with droppers every 3 metres or so which were added as I converted to electrofrogs.
 
#11 ·
KRIS Yes I intended to have districts as you mentioned to help protect the rest of the layout and help locate shorts. On the middle section of the layout will be a reverse loop which will require a module I believe there are also modules for the purpose of
protecting against shorts or at least the damage they can do. I'm afraid my understanding of electrics is poor and it takes me some time to get my head round it. One thing for sure is that I will not buy anything until i'm sure I need it. Good luck with locating
you short. Jim
 
#12 ·
*** The comment from RFS is about right but 32 x 0.2 is much lighter than I would use. Stay with heavier bus wire.

The "Power districts" are useful in that tney will let you have some troubleshooting ability. Start with a simple switch on each to allow you to breal it up if you have problems and add circuit breakers as you have budget available. One 5 amp system will be more than enough overall though.

regards

Ahjay