Hello,
I have an area that runs off my current layout as a spur (WYE) that runs into a dock area with some switching and then eventually will run through a wall itro the other room and into a yard. I was hoping to have the dock area on its own circuit breaker and the yard, however because of the wye and the way i setup the reverse unit Im not sure how i could add a power shield on the reverse lop section, don’t think that works. On my diagram i have marked with red slash the gaps i currently have and it works however this puts the yard and doc area all on the reverse section. I’ve heard of using reverse psx back to back but I’m not sure how that works, I also know that my reverse section need to be able to hold an entire train. Does anyone know if this was the best option or if I should do something different, I can still change some things around at the wye if needed, I think that was the best option for where I put the gaps. The rest of the legs off the wye just pretty mush head to other parts of the layout and loop, that all works so its this section that im not sure about. Any ideas would be appreciated!!
I am running DCC on mrc prodigy elite system
picture below
Thank you!!!
Ward
The people that know the answer to this will want to know about the track plan that we can't see on the left. A to B and beyond and B to A and beyond.
Distance is hard to judge between your Wye and the yard. Where would the longest train end on the way from C to the Dock?
Good idea to use letters. Now we can discuss specific points rather than the turnout in the corner.
Henry
COB Potomac & Northern
Shenandoah Valley
Your approach seems to mirror what is shown here in Example 2. Note the comment that additional gaps would be added between your A & B IF the turnouts had "live frogs". I take that to mean power routing turnouts (e.g., some PECOs), with which I have no familiarity but presume those are ones which require diverging tracks to be gapped in any case(?).
https://dccwiki.com/Reverse_Sections
Paul
Modeling HO with a transition era UP bent
A PSX-AR reversing unit from Tony's trains has the shield built in. Having the entire yard on the reversing section isn't a problem. The reverser will only activate when you cross a set of gaps, and then only if the route you choose is not in phase. Go to tony's site and click products and auto reversers and there will be a diagram of exactly what you want to do.
WardRI was hoping to have the dock area on its own circuit breaker and the yard, however because of the wye and the way i setup the reverse unit Im not sure how i could add a power shield on the reverse lop section, don’t think that works.
Ward,
I'm not clear on the above. If it means you want a separate electrical section (from the wye to the docks) from the yard, you can simply add gaps before the yard and include a circuit breaker for the yard. (Alternately it could be hooked to your main (left side) bus, if you do not want separate breakers for those sections). The caveat is that the distance from C to the added gaps should be more than a train length.
Also, if not familar, it is helpful to understand what happens when a gap is crossed (with metal wheels) in terms of the reverser, track & locos entering or already within the reversing section. If a loco is entering or leaving the reversing section and the polarity at the gaps is not matched, the reverser sees the short and immediately (fraction of a second) reverses the polarity of the reversing section to match the other section, stopping any shorts at the wheels. Locos, either crossing the gap or already within the reversing section, do not "care" about the polarity and change direction, as the decoder just adjusts as needed, just as quickly, to keep the motor going in forward or reverse as set on your throttle(s).
So if you have a loco moving forward, switching in the docks area when a loco from the mainline enters the wye towards the docks and triggering the reverser, the reversing section polarity switches (eliminating any shorts at the gaps) but both locos keep moving forward (with the new polarity). The decoder takes care of direction.
P.S. - I am not familiar with the term "power shield", sorry, if someone can elaborate.
If you don't want the entire yard on the reversing section, gap the rails of the dock/yard track a trains length or so from the first gaps. then you could run the yard off the main buss, or run a separate buss to make the yard a power district, avoiding the reversing section and add a circut breaker to the yard area
Unless you are running long wires or long tracks, you may not even need a dedicated circuit breaker to the yard...just wire it to the bus, but gap it where it meets the tracks you want to control by the reverser. Technically, the main controller for the DCC system should be able to sense shorts wherever the tracks and wiring permit it, providing there are no substantial voltage drops due to long thin wires or great extended lengths of rails running many yards. If the voltage is robust, your DCC controller should detect shorts and cut off power to the rails almost instantly. If you want a bit more insurance, or to isolate the yard for any reason, then a dedicated circuit breaker might indeed be the ticket. 1.5 to 2 amp auto tail light bulbs do a decent job as circuit breakers when wired in series.
WardR
The simplest way is to make the entire tail part of the reversing section, everything from the switch C to the end of the yard.
Old school, pre-autoreverser, you could do that with a DPDT switch attached to switch C that would reverse the entire tail depending on which way the switch was thrown. Simple & cheap.
If you don't want to have the whole branch on one block, you will need a portion that is a train length long, starting with switch C, to be the reversing section.
The reversing section could be its own circuit breaker so you might not need a separate circuit breaker for the tail block.
Having individual circuit breakers or short protection for each electrical block is always a good idea, whether its DC or DCC, if you are running multiple trains. that way one oops in one part of the layout doesn't bring down the whole layout.
Dave H. Painted side goes up. My website : wnbranch.com
peahrensP.S. - I am not familiar with the term "power shield", sorry, if someone can elaborate. Add Quote to your Post
Power shield is the PS in the PSX line of breakers and reverser
Thank you, the section from point c to the dock area will easily hold a train the problem is switcher from the dock area uses or moved over the gap while another train has crossed c would cause a short. Right now I have it gapped at those red marks which means in order to get a short 2 trains would have to crash, my concern was having the yard and dock area all under one psx-ar revering unit.