I have a problem with my turntable actually it’s my receiving tracks behind the turntable, before I wired my tracks all went well, my loco went from the main track to the bridge, it would turn around go my receiving track, now, I have wired my receiving tracks and now there is a short somewhere, I have disconnected the wires to my control, and I still have a short?!!, my turntable is a 130 ft Walthers Cornerstone Nscale I’m running my layout in DCC, I’m running the turntable in analog. I hope it’s something simple that I just don’t see, thanks for the help.
Looks like some of these tracks aren’t wired properly.Identify the faulty tracks and try reversing their polarity.I may be wrong,but since it’s only since you wired them it would make sense.
I agree with Jactal. Where did you get the power to feed those tracks? One is probably crossed. If in fact it is a short and not a lack of power. That has been happening a lot on the Forums lately…some people are confusing short with lack of power/continuity.
Just to clarify, before you were able to use the turntable to turn the loco and there was no short?
Or you did NOT turn the loco on turntable, just moved it to another track and there was no short?
Keep in mind that when you turn a loco on a TT, it must be set up to reverse the track polarity just like any other reversing section. Some turntables handle this automatically. Is the Walthers TT able to do that? Or must you provide reversing apart from the TT?
Finally, you say the layout is DCC and the TT is “analog.” Do you mean the TT is DC and controlled by a powerpack separate from the DCC system? Or just that it requires DC power to turn the TT, but the track power still comes from your DCC system?
The Walthers turntables have a sort of split ring setup to sense when the rotation would reverse the polarity. It is not an auto reverser per se, but the mechanism results in the same effect.
However, depending upon where you place the tracks, the mechanism may not effect a reversal of polarity, in which case, you could need to install a separate auto reverser.
Rich
Edit Note: jacktal’s subsequent reply details what I was referring to in that 2nd paragraph.
The Walthers turntable has indeed the capability to self reverse the polarity of the “bridge” track so that it matches when turn half way around.But for this to work,the TT has to be positioned properly.
I checked mine (not yet installed) and I notice there are two “no track” areas,180 degrees apart…this is the polarity reversing point of the TT.This means that all the “approach” tracks have to be on the same 180 degree half of the TT while the “fan” tracks can be anywhere within the other 180 degree half.
My understanding is that both the “approach” and “fan” tracks have the same polarity and the TT does change the polarity during the rotation,that is providing the “no track” points are properly positioned.You can’t have a mix of “approach” and “fan” tracks on the same 180 degree span in wich case the TT will not convert to correct polarity and shorts will definitely occur.
Jacktal’s latestt post if right on the mark. It is the “No Track” zones. This happened to me just last week. Locos were shorting out on two of my fan tracks. I rotated the pit about 90 degrees and re-programmed. All is well now.
Luckily I didn’t have to move any track. I lifted the rail ends (twelve pair) off the rim of the pit, rotated the pit, then replaced the rails on the pit rim. Also, while the pit was out I had to cut a new notch in the underlayment to accomodate the sensor in the new location about 90 degrees from the earlier position.
I have a double ended freight yard with a turntable approach track on each end. The location of the right hand approach track was on the other side of the NO TRACK zone. At the time, I had no idea of the problem that I had created. I did not understand what was wrong, so the only solution was to install an auto-reverser. It was too late and too difficult to relocate that approach track.
Incidentally, I recently removed that track entirely, some 10 years later, when I redesigned the yard and adjacent engine servicing facility.
As it would be I’m having problems posting my pic of my TT!!! But if you look at richhotrain’s pic, you can see that mine has a similar set up, ONLY I have just one main track going to the pit, and six recieving tracks on the other side, the sensor is facing from left to right, I hope this help’s meanwhile I’m going to have my daughter show me how to post pic’s AGAIN!!![;)]…also time for a[B]!!!
Referring to Rich’s photo, it looks to me that one would want to orient the pit such that the no track area would run from about two o’clock to eight o’clock, or from just to the right of the three tracks leading to/from the rectangular building to the area just camera side of the the garden tracks alongside the round house.
Keep in mind, though, that one of the pre-programmed, unchangeable tracks 1 and 2 will probably be in the middle of the round house fan tracks. I found these two factory set tracks to be a problem, eliminating my ability to number any of my tracks 1 or 2. I start with number 3 with the ficticious story that the original tracks 1 and 2 were removed years ago to make room for a workshop.
Frankly, I found the overall programming parameters quite difficult to work with. It took me four tries to “outsmart” the TT and get it programmed the way I wanted. But I don’t know of an alternative TT that is better unless you spend much more.
I should mention that the NO TRACK zone on my TT runs horizontally from 9 o’clock to 3 o’clock. The track below that Union Pacific diesel is dead. So, all of those other tracks from 8 o’clock to 2 o’clock are on the same side for polarity purposes.
I have a 90" Walthers HO DCC-friendly TT, and there must be something different about it compared to the installations in the above discussion. My approach track and a receiving track are on one side of the no-track zone and another receiving track is on the other side. All tracks are of the same polarity orientation. No problem, no short. And logically, there should not be a short because the bridge automatically changes polarity as it crosses the dead zone. Finally, there should be no difference between an approach track and a receiving track electrically.
Indeed the approach tracks and fan tracks should be wired the same polarity wise thus the need for the turntable to reverse the polarity of the rotating bridge as it turns.The 90’ TT should be designed the same way…I can’t see how it would work otherwise but then I’m opened to learning any time.
There’s another way to void the whole discussion…simply feed the TT’s track power through a reversing module like the AR1.
