Digitrax layout problem.


M

Moeline

New Member
Hello everyone, we're having an electrical issue on our new club modular layout. Hopefully some of you have had similar issues and can share how to solve the problem.

We're using a Digitrax DCS 200 command station and two DB 150 boosters for power. The DCS is wired to main track one, the first DB 150 is wired to main track two, and the second DB 150 is wired to all yard and industry tracks.

The idea being that we have 3 power districts, so that way with plenty of power to operate all 3, and there's insulated joiners separating each track from the other power district at every crossover switch between the mains and every yard and industry track

The wires are connected across the booster input lugs to be sure the boosters are slave boosters, and not command stations, and are not set up as reversing boosters and Loconet cables are connected to all three units.

The problem we're having is any time any locomotive, steam or diesel crosses the insulated joints between the power districts of main 1 to main 2 or main 2 into yard tracks, there's a brief dead short that stops the locomotive.

Some locomotives can make it through, but the short is still obvious on the system and the movement of the locomotive hindered by the short. Any suggestions on how to solve this problem, how to put the boosters in phase, or so on would be greatly appreciated. Thank you.
 
I will try it next week, willing to try anything to resolve the problem
Selector said:
It can't be a short. If some locos make it through, it can't be a short. It is another problem.
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It makes sparks and the locomotive sounds shut down, and the ones that completely stall have the command station beeping about shorted track, so that's all I had to go by on it.
 
If that's the case, then it's the locomotives in question. It's not a short due to wiring or the command station would not apply track power when the other successful locomotives bridge the gaps.
 
Okay. It happened with a Kato SD40, a BLI Mikado, an Athearn SD70, a Bachmann Mikado, pretty much every model we tried to run through there last night at the club, it's a new layout that we're still trying to debug.

Everything works fine when just running in any of the 3 power districts, the problem only occurs when trying to cross over from one power district to another across the insulated joiners separating them.
 
Use a volt ohm meter to test the polarity.
Start out by measuring volt in section 1. One test lead on one rail, the other lead on the opposite rail. It should be around 14 volts a/c.
Now move to the division point between the two powered sections. Put one test lead on one rail of section one and the other lead on the opposite rail but in the other section. If you don't read voltage, move one of the test leads to the opposite rail and read again. If you read voltage with both leads on the same side of the track, but on opposite sides of the track insulators, then your command station is reversed. You correct that by flipping the track wire leads on the right two sockets of the command station then measure voltage again.
 
Okay. It happened with a Kato SD40, a BLI Mikado, an Athearn SD70, a Bachmann Mikado, pretty much every model we tried to run through there last night at the club, it's a new layout that we're still trying to debug.

Everything works fine when just running in any of the 3 power districts, the problem only occurs when trying to cross over from one power district to another across the insulated joiners separating them.
D&J RailRoad said:
Use a volt ohm meter to test the polarity.
Start out by measuring volt in section 1. One test lead on one rail, the other lead on the opposite rail. It should be around 14 volts a/c.
Now move to the division point between the two powered sections. Put one test lead on one rail of section one and the other lead on the opposite rail but in the other section. If you don't read voltage, move one of the test leads to the opposite rail and read again. If you read voltage with both leads on the same side of the track, but on opposite sides of the track insulators, then your command station is reversed. You correct that by flipping the track wire leads on the right two sockets of the command station then measure voltage again.
Click to expand...
Okay, I will try that as well, we had a low voltage problem on main 2 for awhile, but that turned out to be a bad power supply to the main 2 booster which we replaced, the track wiring is done with red and black wires to attempt to keep same polarity all the way around all tracks, it's basically just a double track oval with no reversing sections at all.
 
Thanks to everyone so far for the suggestions that I can try to use to resolve the issue, it's been very frustrating ever since we hooked up the larger command station and boosters, since it ran fine last year on just one Zephyr unit, and only one power district for all three separate parts with jumper wires to use the stand alone Zephyr in the past.
 
Do you have a common running from DCS to the boosters? I would start by following Ken's method(post#8). A RRAmp meter helps with this kind of trouble shooting. To protect the DCS and DB's I would add PSX or some short circuit protection. Check that the power supplies are rated correctly and check the outputs.
All that said, it sounds like you are simply out of phase.
 
jhn_plsn said:
Do you have a common running from DCS to the boosters? I would start by following Ken's method(post#8). A RRAmp meter helps with this kind of trouble shooting. To protect the DCS and DB's I would add PSX or some short circuit protection. Check that the power supplies are rated correctly and check the outputs.
All that said, it sounds like you are simply out of phase.
Click to expand...
No common running between the command station and the boosters at all, only the loconet cable. I also suspect out of phase, but not sure how reversing the track output wires would solve that, since the polarity is correct at the moment. I also tested all track wiring with ohm meter and the Zephyr for test run.

The power supplies for the command station and main 2 booster are Loys Toys "Fuel Tanks" putting out the proper voltage, the power supply for yard and industry tracks booster is a big Digitrax power supply box also with good reading on voltage.
 
There is no polarity in DCC. It is phase. If you have an ohmeter, you can test the phase by testing the AC voltage across the insulated joiner (should be 0 or really close) and then diagonally across the insulated gap (should show voltage probably 10 - 18 VAC). These voltage are just for comparison purposes, they do not represent the actual voltage on the rail unless it is a true rms meter.

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Okay, thanks, I will try that as well, I probably won't get time during the week for the layout, but all these excellent suggestions from everyone can be attempted this weekend at the regular club meeting. Thanks again.
 
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