I have a trouble shooting question that may or not be a potential problem on a layout that is 60' long by 15' wide with two to four parallel main tracks. The 60' length portion has been divided into 4 sidings coming from two main line parallel tracks. The other 60 length, on the other side of the layout, has one parallel track coming off one of the two parallel mainline tracks. That single track leads into a staging area of 4 parallel tracks each about 45' long with a center rail cut in the middle of each track length. That allows two trains per track and 8 trains for the storage area. All sidings and parallel tracks are toggled, so their voltage/amperage and DCS or TMCC ops are not compromised. The original wiring was set up so that one Z4000 and one TIU #5, with toggles off in the right places, could support all DCS and TMCC ops. I used the center of the layout to divide the layout lengthwise into two power districts, as I often only had one train on the mainline or storage track that needed to be shut off and length wise seemed a suitable choice. However, after getting four 3rd Rail E-7's with two of each paired in a TMCC lash-up, a power shortage was created. I added a second #5 TIU and a second Z4000. I then split the layout lengthwise and one Z4000 and a TIU along with a second Z4000 and TIU, could very satisfactorily handle all TMCC and DCS requirement. A third Z4000 is then connected to the 60' X 15' loop, to another second level loop that is 70' by only 6' wide, running along a wall.
This third Z4000 is connected to another TIU #5 and the power is split into 8 different power blocks each being about 30' long for a total of 8 blocks. I divided the 8 blocks between both throttles of the Z4000 so that 4 blocks were 4 consecutive sections of A, B, C, C and then the other throttle handling blocks D, E, F and G.
I run all trains with the cabooses converted so that their rollers do not contact the center rail. That reduces my power consumption "foot print" to the length of each pair of lash-up engines only, rather than the entire length of the train. Yea, I know I don't have a light in the caboose that's operational however; that's not a problem for me.
About a month ago, the new Z4000 on the main loop started to exhibit failures. Sometimes I could get the 19 volts, however; the right throttle had to be all the way back in it's possible rearward rotation. Other times, I couldn't get any voltage output. With the interchanging of wires and outputs I determined it was a right throttle problem and not a track or load on the track problem. I finally had to remove the Z4000 and ship it to an authorized dealer to replace the potentiometer controlling the right throttle internal voltage output.
I added another Z4000 in it's place by powering one TIU, on another part of the layout independent of this loop, by installing four 180 Watt Bricks. That gave me a method to still have two Z4000's to support the 3rd Rail engine lash-ups.
Yesterday, I was staging five DCS trains and 4 TMCC trains to run on a designated loop that would allow me to have 4 TMCC trains on one loop and 5 on a parallel DCS loop so that spacing was easier to maintain without the TMCC "non Legacy" engines and their jerky starts and stops, mixed with the DCS trains. I can run up the DCS trains to X MPH and maintain each train without a of fuss. In order to accomplish the required "start" staging, I had to have each DCS train on it's designated loop only about 12 inches apart. This would only be their profile spacing until I pulled one train out, after another, and traveled to the second elevated portion of the layout giving me a comfortable spacing as the session continued. The dispatching of each train from it's 12 inch spacing, would not be a part of the operating session. It was just a method of getting everything lined up and then pulled out to get it eventual 20' spacing. As soon as that spacing was achieved, I'd start each train and go from there. As I got all trains squeezed in, I obviously was disregarding center rail cuts/ power blocks and which Z4000 controlled which train on the lower loop. This allowed each train to jump the normal footprint of a specific power block with any other powered block. I only had two or trains idling at one time as I squeezed everything up. After everything was staged for the DCS trains, I brought the 4 TMCC trains to their correct location, however, they were kept at normal 20' spacing at a minimum. All trains, TMCC and DCS use the same loop at the same time, drawing from the three Z4000's and three TIU #5's. The four staging tracks that can handle 8 trains, were all toggled off.
After shutting everything down and turning everything off, after a break, I powered up the first Z4000 to 19V and then turned on the second Z4000 also, that powers the lower 60' by 15' lower loop. I then powered up the third Z4000 for the upper connected loop. I had been playing with the intermixing of trains for several weeks and watching the volts and amps on each of the 3, Z4000's, I never came close to anything over 5 amps or a power voltage draw down below 17 volts from the paired 3rd Rail engines. I had three of the parallel loops toggled "on" although some of their tracks were not being used during the previous operations to determine if I had adequate power for any session and I still did not have power consumption problems. However, as I powered up the second Z4000 for it's required voltage, one throttle would not go above 1.5 volts? With a little panic coming on, thinking that my split of power zones on the lower loop may have been a cause of the first Z4000 throttle to fail, I shut everything down including TIUs and then toggled off all the tracks that I wasn't going to use during the session. I then powered up the two Z4000's and no matter how many times I tried to replicate the throttle, not producing more than 1.5 volts, I couldn't get it to fail again. I then turned the toggles back to "on" for the unused sections and still could not replicate the problem. The 8 train staging sections were never toggled on for ops or testing after this event.
After a "lengthy history" of the layout configuration, in order for you understand what I was doing and trying to accomplish without having to ask me a lot of questions, "my question" is one of Z4000 operation when working with other Z4000's on the same loop of tracks. As each train begins it's operations, for a session, each train is quickly overlapping one power block to another and sometimes occupies the same power block of another train at the same time, and it doesn't draw down from one Z4000 to another. However, with this constant block jumping from one Z4000 to another and right throttle and left throttle intermixing different engine voltage and amperage loads, as the session continues, is it possible to send feedback to one of the Z4000's to cause internal damage and one throttle side failure? I would think that a internal Z4000 diode would prevent that. So, before I start rewiring my lower loop so that each entire parallel loop is controlled by one Z4000 with a left and right dedicated throttle and the other parallel loop controlled by another Z4000, with a dedicated left and right throttle, rather than the present division of half of the two mains separated in the middle of the layout, as I have it now, I thought this would be a prudent question. It would seem to me, that after the session started, the sharing of power blocks by the two trains at the same time would eventually occur anyway with the subsequent sharing between Z4000's and throttles would occur at random interval anyway without being able to prevent it.
Does it make any difference in the way I've divided the layout using the center, rather than by
powering each loop by a dedicated single Z4000/TIU? Each loop has two areas that allows a train to travel from one loop to another, separated with a center rail cut
Thanks for you patience in reading this.
Mokemike
lineswest@hotmail.com
