Bruce, it’s true that, “It doesn’t matter where the control rails are” for the parts of the O72 turnouts that he connect to other O72 turnouts. But it does matter for the non-diverging paths through those turnouts, as well as for all the 022 turnouts that he has. That’s why I wanted him to understand that every control rail on the layout must have an insulating pin, and why I tried to let him know through those pictures just where all those control rails are. I think we now have a consensus, that the O72 control rails are the short rails that meet at the frog and that the 022 control rails are as shown in the Lionel service manual.
Thanks for reinforcing the warning about crossing block boundaries. His situation is the worst case, where both blocks might be powered from different outputs from the same transformer. This is the case where the circuit breaker provides no protection at all.
I guess I should also mention that, in any case, the power wiring should be no smaller than 14 AWG, since the ZW’s circuit breaker is rated at 15 amperes. This is a situation where it wouldn’t be a bad idea to install 5, 7, or 10-ampere breakers in series with all the transformer outputs, to protect against accidental connections among them.
I know you guys know what you’re talking about, but all the above has done is pretty much make me decide to pay someone to wire the thing. For instance, what HAPPENS if this happens:
“Then there is the issue of running a train from the inner loop to the outer loop (or vise-versa). A train should not cross an insulating pin in the center rail if the two center rails are powered from different transformers or different transformer taps.”
What does this mean:
"Thanks for reinforcing the warning about crossing block boundaries. His situation is the worst case, where both blocks might be powered from different outputs from the same transformer. This is the case where the circuit breaker provides no protection at all.
I guess I should also mention that, in any case, the power wiring should be no smaller than 14 AWG, since the ZW’s circuit breaker is rated at 15 amperes. This is a situation where it wouldn’t be a bad idea to install 5, 7, or 10-ampere breakers in series with all the transformer outputs, to protect against accidental connections among them."
You mean after doing all this I could destroy my transformers, wiring, entire system, and burn down my building? You have to realize that you’re not talking to someone who understands all this stuff. I understand what circuit breakers do, but how can you have a situation where a circuit breaker will do nothing? WHAT WILL HAPPEN, and why is this the “worst case”? Are you telling me that if whatever you’re talking about happens, that I’ll have no indication of it, no circuit breakers will break the circuit, and basically after it happens I should just throw the layout and all the trains on it in the dumpster?
In short, while I appreciate the help, you’re talking Greek to me in a lot of this stuff, and I’m sure I’m not alone in feeling that way.
Tony, when my kids were younger, they would demand that we help them with school work that they did not understand but then throw tantrums when our explanations didn’t immediately enlighten them. As they have gotten older, they have become much more reasonable, but back then it was no fun to try to help them. I felt a duty to keep trying, which does not extend to helping people with their toy train wiring problems. The old-timers here know that I will keep explaining pretty much forever for those who can patiently and politely question what they do not understand. But, if you want to shoot the messenger, we don’t need to go further.
We are trying to help you, without being able to see your layout or your equipment and without knowing which of many details are obvious to you (“I understand what circuit breakers do…”) and which are not. That is not as easy as you might imagine. Toy train layouts are not in fact the simplest of electrical systems. I will answer what you have asked in your last post; and then we can see whether we want to continue.
o “What HAPPENS if this happens: ‘Then there is the issue of running a train from the inner loop to the outer loop (or vise-versa). A train should not cross an insulating pin in the center rail if the two center rails are powered from different transformers or different transformer taps.’”
If there is any difference between the voltages from the two sources, a fault current flows between the blocks through the locomotive’s or lighted cars’ pickups. This fault current can be quite large.
o "What does this mean: 'Thanks for reinforcing the warning about crossing block boundaries. His situation is the worst case, where both blocks might be powered from different outputs from the same transformer. This is the case where the circuit breaker provides no prot
I know this layout. It was featured in the November 2004 issue of CTT titled: “High Speed in 6 x 12 feet.” It was only a 2 page spread with no info on how to wire it, so yes it will give you fits.
I’m wanting to build this layout in conjunction with another for my grandkids, so I’ve been taking my time studying what Bob Nelson and other’s say concerning wiring and electronics, taking notes,and making my own diagrams over and over to better understand what I need to do. Like you I am not well versed in this, but with time, patience, reading and rereading, research and contemplating, doing some practice wiring and asking more questions, you will get there.
As much fun as I think this layout is, I don’t believe it is a layout for the novice as far as wiring.
Seems to me that if I always remember to have the correct rail to the common terminals on the transformer, and have the insulating pins installed as noted, I should be OK. In any case, thank you for your help. No further tantrums will be thrown.
As to the comments at the start of Mr. Nelson’s last post, made, it seems, at my expense – there’s an old saying I remember – something about not expecting to be told how to make a watch when you just want to know what time it is.
Capt, Both Bob Nelson and I are electrical engineers with combined experience approaching 100 years. I suggest you take the time to understand and heed what Bob is telling you. It is extremely well thought out and he has your safety in mind. He has analyzed the potential problems with transformers and layouts at great length. And no, you will not always be OK if you just have the common terminal of the transformer on the outer rail and insulating pins installed correctly. I suggest you protect each output terminal of the transformer with an appropriate circuit breaker, probably 5 amps should be OK. Then, even though you don’ t fully understand what you are doing, you should be safe. OK?
I guess this is why I run my trains on separate tracks and have only used my switches to park trains that I don’t run and has no power. However I would like to get more adventurous and was wondering, what book would you recommend for a novice like me to start learning some of the concepts you speak about. From searching the forum it seems the book Wiring Your Train Layout by Peter Riddle would be a good start but I was wondering if you have any other suggestions.
From what I have understood, Peter Riddle would not be the best reference for layout wiring. I think the best would be to read whatever Bob Nelson (lionelsoni) and Bruce Baker (servoguy) have posted, save those pages and take many notes and practice doing what they recommend. Other’s on this forum also have great experience, I just don’t remember their names right off.
I don’t know of any good books on the subject. I have a pretty low opinion of Riddle’s understanding of electricity. You may be able to find some postings of mine with detailed criticism.
The circles in red show where the insulating pins for the non-derailing feature need to be placed. If there is a transition between power districts / blocks at the switches, the blue circles show where the insulating pins are placed for that function. (click image for larger view)
Bob and Bruce, so here we are 7 years after the original post and I find myself trying to do the same thing. I’m proud to say that, before I read the thread, I was able to determine where the rails needed to be insulated. As I read through the thread I was able to understand most of what I read. I was hoping to run a train from the inner track to the outer and now, unfortunately, I understand I cannot do that. I’m sure glad I found this thread before I ruined my layout wiring! Is there any way, other than using the switches as shown in the picture, that I can run separate trains on the inner and outer tracks and have the ability to move one train from one loop to the other?
Yes. The straightforward and safe way to do it is to create track blocks on your layout.
To make blocks, simply put gaps (or insulating pins) in the center rail at the block boundaries. Connect the center rail of each block to the common terminal of a single-pole-double-throw-center-off switch. Connect one terminal of each switch to one variable-voltage transformer output and connect the other terminal to another variable-voltage transformer output. Connect all the outside rails (except for control rails for turnouts and accessory activation) and all the transformer commons (if using more than one) together.
You will then be able to select for each block, which transformer output will power the block, or to turn the block off completely. So design your block boundaries so that you can make the moves that you want. This will probably require at least two blocks on each loop. For example, one train can wait in one block of loop A, while the other train crosses from loop B into the other block of loop A. Then the first train crosses from loop A to the vacated block of loop B.
Blocks can also be very handy in trouble-shooting short circuits.
