DCS, Z4000, 022 Problem?

Follow up: I just ran an MTH Proto 2 on both my outer loop and inner loop main lines, and everything worked fine.

One more thing: when I adjusted the track and 022 switches where the fiber pins are, I noticed a fixed voltage plug was not inserted all the way in, so I fully re-inserted it.

I wonder if this mystery involved a combination of problems, like the title to this topic suggests. What do you think?

Are your transformers phased?

  I would check for the answer to Gerald Jackson's question - The behavior you are describing is very much like the behavior one gets when the transformers aren't phased.

@Arnold D. Cribari posted:

This is a mystery to me. Last night my trains did weird things.

While I was running a freight train headed by an MTH Proto 1 Trainmaster (very reliable engine) on the outer loop, and a passenger train led by an MTH Proto 3 engine on DCS, suddenly the Trainmaster took off like a Jack rabbit.

When I moved the MTH throttle to the off position, the Trainmaster still ran at top speed, so I ran to a location on my layout where I could reach the racing engine, grabbed it and removed it from the track.

Next, I did several things in an effort to diagnose the problem, including testing the inner loop controlled by the other Z4000 throttle (perfectly normal), and unplugging the DCS with the outer loop Z4000 throttle in the off position (no power to the track).

Next, I plugged the DCS back in, tested the outer loop again, and this time I could only get 2 volts of power when I moved the outer loop Z4000 throttle to full power, not enough to run an engine.

After checking my wiring connections to my two Z4000s (the other Z4000 controls my 8 sidings that worked fine) and DCS. Everything seemed normal.

Next, I turned everything off for a few minutes, tested the outer loop Z4000 throttle, and again could only get 2 volts of power, not enough to run an engine.

It was getting late, so I turned everything off for the night.

Early this morning, I tried again to diagnose the problem.

I looked at the DCS wiring again, and saw that one of the wires to the outer loop input terminals was loose, so I tightened it. I turned the power on and the outer loop Z4000 throttle worked normally, and I could get full power. However, I noticed that the power for my numerous 022 postwar switches was off (the switches have fixed voltage plugs and get power from an old ZW).

Next weird thing: with the outer loop Z4000 throttle in the off position, I turned the ZW power on for the 022 switches, and I got power for both the outer loop track as well as the 022 switches.

Next, I checked out the track and 022 switches on my layout where the MTH Proto 1 Trainmaster first started racing. I ever so slightly adjusted the track and switches where the fiber pins are. I tested again the outer loop Z4000 throttle and the ZW throttle for the switches, and everything returned to normal.

I tested the outer loop track running a Postwar switcher, and it ran fine.

Later today, I will test the outer loop running an MTH Proto 2 or 3 engine on DCS. I suspect that it will work normally.

Any thoughts about this mystery?

Arnold

Arnold, I moved this to the MTH DCS forum since you are discussing that topic and not a 3-rail traditional toy train topic.

My guess is that the loose wire connection to the outer loop was the cause of the Proto 1 engine taking off like a jackrabbit. I know that DCS engines can switch to conventional mode if the power is interrupted briefly. This happens because the TIU only sends out the watchdog signal when power is first applied to the input of a channel.

If i am following this right, the problem was the 2 loops made connection causing the PS 1 engine to take off.  PS 1 engines only run in conventional and they don't see a watchdog signal or run in DCS. The 022 switch had nothing to do with this problem and only runs with track power when the plug came out instead of transformer power.

This problem is not a DCS, Z4000, or switch problem in my opinion.

@Gerald Jackson posted:

Are your transformers phased?

Yes

@OGR posted:

Arnold, I moved this to the MTH DCS forum since you are discussing that topic and not a 3-rail traditional toy train topic.

Ok, that makes sense.

Thank you, John and Joe, for your input.

@Joe Allen posted:

If i am following this right, the problem was the 2 loops made connection causing the PS 1 engine to take off.  PS 1 engines only run in conventional and they don't see a watchdog signal or run in DCS. The 022 switch had nothing to do with this problem and only runs with track power when the plug came out instead of transformer power.

This problem is not a DCS, Z4000, or switch problem in my opinion.

What is still a bit of a mystery to me is that something caused the outer loop track power to be at a high voltage, even when I turned the MTH outer loop throttle to the off position.  John may be correct that a loose wire connection for the outer loop to the DCS input terminal may have been the cause of that.

Another possibility is that when the 022 fix voltage plug got loose, the outer loop track somehow got high voltage, even with the Z4000 outer loop throttle in the off position. IMO, the only sources of that high voltage are the DCS, or the ZW that provides power to the 022 switches.

Arnold, I'll freely admit that DCS is something I know little about.  Not saying this is the problem, but thinking about other possibilities, maybe this is something to look at.  It sounds as if maybe power from the ZW was getting to the outer loop until you shifted the track just enough to separate the adjacent track from the O22 power.

Do your fibre isolating pins in the O22 switches have small shoulders on them designed keep the adjacent track physically separated by ~1/16", and if so has one of these shoulders maybe been shorn off, so that now it's allowing the connected track rails to touch when shifted a certain way?

@SteveH posted:

Arnold, I'll freely admit that DCS is something I know little about.  Not saying this is the problem, but thinking about other possibilities, maybe this is something to look at.  It sounds as if maybe power from the ZW was getting to the outer loop until you shifted the track just enough to separate the adjacent track from the O22 power.

Do your fibre isolating pins in the O22 switches have small shoulders on them designed keep the adjacent track physically separated by ~1/16", and if so has one of these shoulders maybe been shorn off, so that now it's allowing the connected track rails to touch when shifted a certain way?

Steve, I think what you say is very possible. When I ever so slightly adjusted the track and switches where the fiber pins are, I didn't think that doing that would make any difference, but when I did that, the problem was solved. Boy, was I relieved.

I thought tgar I might need to do a tremendous amount of work involving the DCS and the wiring on my layout. I still may need to do that work some time in the future.

The only way the outer loop can get voltage with the transformer handle off with the inner loop powered is with the 2 loops connected by the track or a train crossing over to the other loop. The plug on your 022 switch will not cause the problem.  Again, it has nothing to do with DCS or your transformer.