Adding Power Districts

[wm3798]

I'm beginning to realize that breaking up the layout into power districts might be a sensible thing to do.  First, I'm powering all the frogs in my active yards, which is bound to create shorts as lazy brakemen let their engineers foul switches set against them.  Second, the new staging yard for the west end is crazy big and pretty far flung from the power unit.  Third, I don't want to have to dissect the entire layout to chase down a ghost that I know sooner or later will haunt me.

I know MRC offers a booster to accomplish this task, so I suppose I'll be needin' two of them.

Here's what I'm thinking:  one district to handle the east staging through to Maryland Jct., one district for the Thomas Sub to Elkins (or would that be overkill?) and one for the Connellsville Sub from MY to staging.

Here's the track plans:

Lower level


Main Level - Ridgeley


Main Level - Elkins


Thoughts?

Lee

[Philip H]

that seems like a good break up of the parts.  My only other suggestion would be to think about having both staging yard on the same power block and then the visible portion divided in half - that way when I end up backing half a train onto the wrong track coming out if North Junction to avoid Bryan, I won't shut down half the main - and kill Ed's hostling duties in Ridgely.   :

[Pomperaugrr]

I just installed a PSX-3 (whick is just three PSX-1's connected by scored circuit board segments) from Tony's Train Exchange.  I ran a 14 ga. power bus around the layout and then branched off to each PSX unit.  I had actually separated each PSX unit for localized placement in the separate district.  Getting the PSX-3 was cheaper than getting three PSX-1's.  These work great.  I have intentionally shorted out each district.  It is an immediate shut down and automatic restoration of power when the short is cleared.

Since you have existing wiring on much of the layout, you coule easily daisy chain these, since there are power in and out terminals for your DCC bus wires.

Eric

[Ian MacMillan]

Eric are you also using BDL168s? I'm having some trouble figuring out how to go about hooking up the PSX's with a block detection blocked layout.

Like Lee, I too am figuring I am in need to split up the layout into power districts, and not just to prevent shorts from shutting down the whole layout, but the amp demand by so many locomotives.

[Pomperaugrr]

Ian, no, I'm not doing block detection.  The Housatonic is a single track shortline and is all dark territory.  That saves Mr. wallet from the added expense of signal system wiring.

I am just using power districts as circuit breaker protection and power distribution.  I am not using block detection.  I found that by dividing what I have of my layout so far into 3 major power districts each fed off the main DCC bus, I am able to avoid any significant voltage drop across the layout.  I will add two additional power districts when I finish the double deck portion in the small room.  I have only built the layout in the main 13 x 21 room so far.

I ran the main 14 ga DCC power bus around the layout.  I only fed 14 ga lines off of that in the locations where I had to feed each of the PSX and reverser units.  Granted, I have only tested with a total of 9 locomotives in the various areas, but it worked great.  I did not want to daisy chain the power supply lines for the PSX units, for fear of experiencing a power loss if there were too many locomotives in one area.  I will probably not be running more than 6 locomotives at a time for normal operations, so this works for me.

So simple explanation is:  Main 14 ga. power bus, with 14 ga. feeders only to PSX and AR Units.  There are no track feeders off the main power bus.  Then I have 14 ga. power district bus wires running out from the PSX and AR units, with 22 ga. feeders from the power district bus to the tracks.

I cut my track gaps directly across each other for the power districts and reverse loop areas.  I used styrene to insulate the gap and have had no hesitation or other issues with this approach.

Eric

[Ian MacMillan]

Sounds good!


Hey block detection just isnt for signaling! Helps out the dispatcher if you use a computer!

[Pomperaugrr]

I will definitely use block detection on future layouts where there is more train action, but thanks to the Housatonic being a small shortline and me being a lone wolf, there is usually only one train working the south end and one working the north end of the line, just like the prototype.  I really can't justify it on this layout.  I have infrared occupancy detection for semi hidden staging tracks and spurs inside buildings.  That should meet my needs for now.

I can see Lee needing it, as he has numerous operators during operating sessions.

[wm3798]

Here's the occupancy/block detection system I employ...



Well, it's a little risky, but the price is right!

lee

[cv_acr]

I'm beginning to realize that breaking up the layout into power districts might be a sensible thing to do.  First, I'm powering all the frogs in my active yards, which is bound to create shorts as lazy brakemen let their engineers foul switches set against them.  Second, the new staging yard for the west end is crazy big and pretty far flung from the power unit.  Third, I don't want to have to dissect the entire layout to chase down a ghost that I know sooner or later will haunt me.
...
Thoughts?

Lee

Good idea. That's what we're doing at our club too.

Advantages are as mentioned; a short doesn't knock out the _entire_ layout, when there is an unexplained short it's slightly easier to narrow down the area (depending on the size of your power districts), and if you have a lot of engines (especially ones with sound that may draw more current) or lots of lighted passenger cars, freight cars with resistance wheelsets for current detection, etc., there's more power available in each district.

We've gone a few steps farther than that as well, each power district from a DCC booster is broken down into sub-districts using circuit protectors, to further isolate shorts and "oopsies", and the plan (implemented in the main yard so far) is to also further break things down into sections/areas that can be turned off with a toggle switch for maintenance and troubleshooting while the rest of the layout is running.

A note though, make sure your districts are in fact properly isolated, or you're just going to have both boosters providing twice the amperage to the entire layout. In fixing the wiring in the yard a couple years ago, we found that instead of two districts on separate boosters that we should have had, there was actually a connection under the yard between the sections so instead of two 5-amp districts, the whole layout was a single 10-amp circuit. Probably explains why we haven't smoked nearly as many decoders since the yard was re-wired...