Possible reverse loop short, I have two interconnecting ovals with two PWR blocks each, running one train on both ovals individually, power from a lionel PW ZW and MTH DCS, I added two RH 072 K-line switches as a crossover now I get both trains running together or signs of a short no movement low illumination, the swithes are isolated all three rails turnout to turnout.
Lost, what I have seen I should not have a problem.
Please help.
New to forums, hope I’am in right place
You are absolutely in the right place–there are some really smart guys on here, of whom I am not one–but at least, I will try to start process. First off, I believe the reverse loop design is irrelevant; usually a factor in two rail setups but not three rail.
Now lets see what else? You stated “power from a lionel PW ZW and MTH DCS” First off, you have to “phase the transformers”; this may be tricky but in theory it works as follows: Plug both in, and determine which terminal from each one will go to the outer running rails. You need to have a wire connecting both of those terminals to each other, and a wire going from either one to the outer running rail. Then get a voltage measuring device (multimeter?) and and read the voltage output from each transformer by putting one probe of the multimeter on either of the two already connected terminals, and the other probe on first the terminal which will connect to the center rail from transformer A, note the reading, and then to the terminal on the other transformer which you will connect to the center railand note that reading. Adjust the throttles until you get pretty much the same readings of voltage. Now take a length of wire and connect it to either of those terminals which you plan to connect to the center rail. Touch the other end of it briefly to the terminal on the other transformer which you plan to connect to the center rail. You should get a very small spark, but nothing very much. If you get something akin to what you get when you accidentally short out the center rail with a running rail, then reverse one of the plugs in the 100volt outlet. and try this “spark” test again. When the spark is quite small you have the setup in the fashion which will allow the transformers to be used together on different segments of the layout AND allow a loco to run from one of those areas controlled by transformer A to the other area controlled by Transformer B. Now if you have the two loops seperat
Appreciate reply, actually troubleshooting right now, the ZW I’am using is setup as follows RT handle to TIU variable 2, RT inner handle to TIU fixed 2, LT inner handle to TIU fixed 1 and LT outer handle to TIU variable 1,
Variable channel control track blocks, fixed channel control four switches each, no second transformer to phase.
Ok-- I have to bow out–I guess I am not current enough to recoginze that the MTH item you mentioned is not a transformer. I really ought to get out more! I’m sure someone else will come in here with some comment, first–don’t listen to stuartmit, and second, here’s what to do!
be patient–you just started this thread today; probably by tomorrow you’ have your solution from someone more versed than I, and I’ll learn too.
I don’t know what a TIU is nor know anything about it. But I ordinarily strongly advise against running between blocks powered by different transformer outputs, particularly when they come from the same transformer, like the traditional ZW. That doesn’t explain the problem here, however, which I understand is happening even when the trains aren’t crossing the block gap.
(I’m in San Antonio for an Army shindig concerning my son’s deployment to Afganistan and just now got onto the Internet.)
I think I’m getting it as far as what you are running. Are you using the Variable channels and the DCS remote to run your trains on the 2 loops ?
Is the short present on just the initial power up of the layout or only when traversing through the crossover ?
First off. Dissconnect the power for the turnouts that are running through Fixed 1 and 2 of the TIU. Run the power directly from the ZW to the turnouts motors. There is no need to run power through the TIU for these. Use the TIU to run trains only. The commons or black terminals on the TIU I believe in the earlier versions are connected. It sounds like when you are hooking everything together you are creating a short. Another thing. Make sure you have a fast blow fuse between the ZW and the TIU. The early version TIU’s offer no protection. A slow acting breaker in an old ZW can fry the TIU.
The ZW is protected by fast acting fuses,Varible channels and remote operate trains, fixed channels supply power for switches, as of now there is no power to the crossover switches completly isolated, short occurrs at initial startup.
[#welcome] to the forum!
About the TIU and powering it. Do you have the common or U terminal wired to the black lugs or terminals on the TIU? Next do you have the black terminals wired to the outer rails only? The A, B, C and D terminals from the ZW should go to the red lugs(variable one or fixed one or two) or terminals on the TIU. You must run all power wires first to the TIU then to the track, even the common or negative wire.
Do not run switch direction power through the TIU, you need to have the switch wired into an AIU to throw the turnouts using the handheld remote. The original remotes that came with the switch will work if you don’t have an AIU.
Also the TIU can be powered by a seperate transformer, like a 75 watt MTH block type transformer(from the MTH Z-750). I did my TIU this way as I got a 75 watt transformer for $15.00 at a train show.
If you add an AIU it must be wired in then each item added into the handheld remote.
Just a word of advice when adding engines to the DCS handheld; one engine on the track at one time. If you have a second engine on the track the handheld gets confused and adds both engines in as one engine, this happened to me recently.
Lee F.
Take the switches off the TIU and see what happens. Run power to the switches from the ZW directly if using the constant voltage feature on the switch, set the voltage with a multimeter for what the manufacturer suggests for maximum voltage.
Fuses are good protection but you may want to change to circuit breakers to keep from buying fuses all the time.
Lee F.
Disconnect any power going to the turnouts motors and treat the layout as 2 seperate loops. Each powered by the 2 variable channels. Remove the trains as well. Start by placing a lighted car or engine on one loop and check the results. Keep moving on and hopefully you will find the root of the problem. If both loops and trains check out. Go back then and deal with the 2 turnouts as far as wiring them. Wire them directly from the ZW at the voltage required.