Digitrax tripping

My club runs a Digitrax Super Chief system with a DCS100 command station and DB150 booster. Recently, the reversers attached to the system started chirping, about every 4-5 seconds. I isolated both reversers, and the problem didn't go away, so I think they're fine.

Both command station and booster flash off every 4-5 seconds, then immediately come back. What this does is make headlights blink, on it'll stop locomotives without flywheels. Sometimes, engines take off on their own.

I've tried isolating sections, but the problem still remains. However, when I disconnect the loconet cable between the command station and booster, the problem appears to go away.

Does anyone have any ideas what could cause this? There was no configuration change before the problem started that I know of. (We have not yet tried resetting the system.)

Puckdropper

Reply to
Puckdropper
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I would double-check all of the wiring, particularly that related to the power supply and data connections to and between the command station and the booster. How are the reversers controlled ? Do they receive their instructions via the DCC track power ? If not then double-check the separate cable. Have you tried disconnecting all but one of the reversers and seeing if the problem persists ?

Bizarre behaviour like this is often due to things like missing or poor ground connections. I don't know what loconet is like electronically, or what the connectors are like, but that would be a place to start looking. If you have a spare loconet cable that should be early on your list of things to try.

By `resetting' I assume you mean putting the command station, which I assume has some nonvolatile memory for configuration etc., back to factory settings. This will help if the fault is due to an error in that configuration (perhaps abetted by buggy firmware).

Do you have access (perhaps via one of your members) to a spare command station and/or booster which could be tested ? I don't know if people conventionally build this kind of thing in in a way that makes it difficult to remove and disconnect temporarily; I wouldn't but the result is that a substantial proportion of my not inconsiderable electronics budget goes on connectors.

Reply to
Ian Jackson

What kind of reversers are you using? If you're using the PM42's, then the "chirping" is really just the relays clacking. In my experience, they tend to clack like that when the power keeps cycling on and off. It usually has nothing to do with the reverse loops themselves.

How many beeps is being sounded when this happens? Five beeps is a short.

I would say that there's something shorting the booster section. It could also be that the brain and the booster are out of synch. You do have them grounded to each other, right? Also, have you tried just shutting down the booster, rather than unplugging the LocoNet? Also, you do have the wire in place to force the DB150 to be only a booster and not a command station...I hope.

I have also discovered that stuff like this can happen when you have short across booster sections. BTW, are you using any kind of cicuit breaker independant of the booster's own? Something like a PSX or PS(one) or PM42? Free advice: don't use the "brain" DCS100 as a booster if you can help it. It can cause issues if it's powering a section adjacent to a reversing section.

Paul A. Cutler III

************* Weather Or No Go New Haven *************
Reply to
Pac Man

"Pac Man" wrote in news:PvS3k.7262$3j2.4886@trnddc03:

MRC AD520s, they're relays powered off the DCC bus. Normally, they don't make much noise at all, but after this problem occurred they've been clicking every 4-5 seconds.

No beeps.

I'm certain, without looking, that the wire is in place. There was a note next to it explaining how to do that. I will check the grounds Thursday.

I'm not sure about that. Apparently the layout was supposed to be broken in to power districts, but it doesn't work like that. Usually a short stops just about everything.

Puckdropper

Reply to
Puckdropper

Ian Jackson wrote in news:2Lc*1N+ snipped-for-privacy@news.chiark.greenend.org.uk:

They're MRC AD520s. I'm guessing the relay waits until it senses a huge current draw (a short) and then flips. I've isolated the reversers (one runs off the DCS100 and the other the DB150) and the problem stil remains.

I'll take a look at that. All the loconet panels are Digitrax, so isolation won't be a problem.

Usually things are built so removal and disconnection is more difficult. Less hassle, less effort...until something goes wrong. That's not a reflection of my club's wiring job (which isn't terrible), it's an observation of how things are normally done.

If we need it, I'm sure we can get a spare command station somewhere. The club's run with only the DB150 before, so we could probably do so again.

Puckdropper

Reply to
Puckdropper

!

What an astonishing design. Well, err, forget most of the rest of what I said. I had assumed that these things were actually controlled somehow rather than just waiting for the short and then flipping.

I did a bit of websearching and it suggests that they're adjustable. That is, the current at which they flip is adjustable. Have you tried increasing it ? This will (as the sites I saw agreed) increase the energy in of the sparks and thus the damage to the wheels each time they operate but such damage is inevitable with the design.

Reply to
Ian Jackson

That's the way all auto-reversers work.

Damage? Nope. I've been running auto-reversers on my club's layout for

7 or 8 years, using an MRC, a Digitrax' PM42, and a Digitrax Booster set up for it. I've never seen sparks at the electrical isolation gap of an auto-reversing section in use. The reversers are so sensitive & quick that they trip without sparks. Honest.

Paul A. Cutler III

************* Weather Or No Go New Haven *************
Reply to
Pac Man

Are they clicking in time with the booster and brain shutting down? If so, then it's not the auto reversers.

None? Hmm... Well, it's possible you have the beeps turned off. Or, it could be that the short or whatever is too quick for the beeps. Just thought of something...what kind of load are we talking about here with the locos? Are there a lot of sound locos on the track?

FYI: On my club layout, the screws actually were loose on a couple of our boosters with that wire. I was able to tighten them a full turn, and some of our erratic operation went away after that.

Ick. If you're running a club layout, you better rewire that or it'll drive you nuts. At my club, we have one DCS100 & 8 DB200's. One of the DB200's powers a freight yard, and another powers all our stationary decodered switch machines. The other 6 power the mainline. Each mainline booster powers 1 or 2 power distribution/detection panels scattered throughout the layout. Each panel has 4 circuit breakers from Tony's. Each of these breakers powers 1/4th of a BDL168 block detector (which detects up to 16 blocks in four zones). The BDL168's 16 outputs go out to the track bus for each block. On our layout, if there's a short, it only effects 4 blocks (unless it's at a boundry...then the booster trips and knocks out a large chunk o' layout). Each mainline block is about 15 feet, BTW. IMHO, you really should get some circuit breakers and divide up your club's layout. Maybe not as much as we did, but still...ick.

Paul A. Cutler III

************* Weather Or No Go New Haven *************
Reply to
Pac Man

So I now discover. I didn't have the dubious benefit of knowing this when I designed my own arrangements so I have a system where the polarity is set correctly before the train arrives. (Well, I probably wouldn't have done it differently anyway ...)

OK, I believe you. Versions which use solid state relays rather than electromechanical relays should certainly be able to limit the energy released to reasonable levels. My own layout has of course a short-circuit cutout which is sensitive enough to prevent any damage so it must be possible.

The OP however was using relay-based reversers which will be much slower. Also, I imagine the relays' contact lifetime is not ideal due to arcing when opening carrying a fault load. I wonder if they manufacturers have done tests to determine whether the relays still have an acceptable service life.

Reply to
Ian Jackson

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