Electrical problem (DC) . . .

Hey gang - looking for some assistance. I just added an additional staging track to my layout (probably about 20' long or so), and am now seeing an intermittent electrical problem. I run DC, and have an MRC 2400 Tech II power pack. What happens is that it drops power at times to the point where it doesn't have enough to drive a train - and when I turn it up all the way, the red 'overload' light comes on. I thought I solved it this morning, when I switched the points on a new switch on the new track (a Peco Electrofrog) to be lined with the train, but it came back tonight. It seems I can fix it if I turn all the blocks off except for the block that the train is in (the train in question has 4 Kato locos up front). And it doesnt' happen all the time - I had a train going earlier today for a good while w/ no problems. And, it happens when the train is NOT on the new track - tonight it happened when a train was on the complete other side of the layout - track that has been down for 3+ years.

So my question - is there a limit to the amount of track/wiring that 1 power pack can support? And are my symtoms an indication of exceeding that limit?

I don't want to start a DCC vs DC flame war here - I know I should be running DCC, but I'm not yet. . .

Thanks
Dave

 

Sounds like you have something inadvertantly cross or loose wired to me (and don't ask how I know this).....

I have had this problem occaisionally, and somehow, the block wiring is messed up, with more than one block getting power when I turn on the intended new block.

Try running the train with all blocks except one other one on. Sooner or later, you should figure out where the power is being zapped to.

Or. with the power on, try putting your hand on the rails. If you find a warm spot, you have some kind of short where the power is going there in large amounts, rather than over the whole layout.

If you have intermittent power, is it possible that under the table two or more wires aren't insulated, and are touching each other, transmitting power other than where intended?

How did you connect the power to the track? Solder? Is that joint loose? Or is it loose (ie not soldered) where you tapped the other wire to power the track?

Lastly, it is possible that something like a rail joiner or blob of solder used when installing the new track is intermittently touching a track, and messing up polarity.

But. from the sounds of it, you may have more than one block connected to that track inadvertantly. The Tech II should be able to run a fairly large sized layout.

 

I had a problem with a throttle that had to be cranked up to almost maximum to get a locomtive to move at times, yet at other times would start the same locomotive at 1/4 throttle. Turns out it was the contacts on the reversing switch! When I pressed on the switch power was restored. TV Tuner cleaner in the switch solved it.

Is either track double ended? Might have a problem there with electrofrogs. Also, could be one of your locomotives. Or, it could be a bad power transistor in your power pack. One additional track should make no difference if you're running no additional power units.

 

Thanks guys - still troubleshooting, I'll keep you posted. I have since been unable to reproduce the problem, everything is running fine. This is a perplexing one! I'll keep you posted.

Thanks
Dave

 

Get a RRampmeter and check the voltage to the track and the amps put out by your power supply.


The RRampmeter works for DCC as well as DC Layouts.

 

I have the same problem, on occasion. In fact, just now. Have you recently (last day or so) used alcohol or diluted glue in laying down scenery or ballast. I created my own shorts doing this. Let it dry out if this is the case. Otherwise, it sounds as if you have a cross under the table. Are all wires separated? If you are using an Atlas Connector with the offending block and you have a spare, try it. If no spare, wire the offending block directly to your power pack. If it now works, you may have a faulty controller. If you are using pre wired or self wired terminal rail joiners and your track is not securely fastened or ballasted, after a while the weight of the train going over the block of track may have loosened the rail joiners or even rubbed the insulation from the wire itself, if it was drawn tightly enough under the table. It may be in contact with another wire or a bolt.
Other than the above, I have no clues and would suggest rewiring the offending section, making sure your insulated rail joiners have remained gapped from the rail.

[ 01. August 2004, 17:35: Message edited by: Fotheringill ]

 

AHA !!! Yes, Fotheringill - I ballasted a short section of track going into a tunnel I'm putting in (it's hard to ballast inside a tunnel once you've put the portal and mountain in!). So yes, that could very well be it! Could also explain why I can't reproduce it now - the ballast has dried overnight.

Thanks for the help
Dave

 

In fact, Dave, it can get SO WET under the rails, the following can, and has just, happened to me:

I have 4 Tech 4 260's. Only the A Power Pack was on. The others were off. When rolling over an offending area, the power light on the B Power Pack went on for a second or so and the A unit showed an overload.

Let things dry out for a day or two. If it persists, then trace the problem back as suggested by the posters who responded.

[ 01. August 2004, 22:27: Message edited by: Fotheringill ]

 

Hopefully, you've got your problem solved with the ballast situation. If not, I'll toss out another thought....

You mentioned that you were running four locos. Despite the "ratings" and marketing claims of MRC, I think that is pushing it for one of those packs. I used to use a pair of MRC 2500 Tech II's to power my layout, but recently upgraded to a pair of Tech III 9500s. They aren't cheap, but I like the power for multiple unit lash ups and I also like the built in voltage and amp meters. Whereas both of my Tech II's used to get physically very warm when running four engines, these stay cool. In addition to the heat, I was starting to see intermittent performance from one of my Tech II's similar to what you've described. Good luck.

Jack

 

Jack -
Since you mentioned it, my 2400 does get warm when running multiple unit lashups - but I haven't had any problem with it (until this, which is sounding like it may not be the controller after all. . . )

I've been toying with the idea of getting another power pack for the urban/yard section of my layout - which would enable me to have a train running on the mainline, and do switching at the same time. Now I'm really thinking about it hard.

OBTW, no problems at all today so far - I've had several trains running w/ no glitches, so the wet ballast theory may have solved it.

Even though the wet ballast was on a block that was turned off, I only insulate one side of the track on my blocks, so it could have still been drawing juice from the 'hot' rail and shorting out the other side.

Dave

 

Dave-

Kind of gives you that "Oh ****" feeling. Please let me know through post or mail if the situation reoccurs since we appear to have parallel problems (no pun intended).

 

Yea, I know what you mean about the 'Oh ****' feeling - spend a ton of time wiring something up, and then finding a problem on a section that you didn't work on!!!!

Luckily, all is still well - ran trains all day w/ no problems, so (knock on wood) I think it was the wet ballast. But I will keep you posted if the gremlin (or "stray 'trons" as we used to call them in the Navy) comes back.

Dave

 

Dave,

You mentioned you're using Electrofrog turnouts, which power the outgoing rails by the points. I believe you problems results from attaching power feeder wires to each yard track. This will cause a short when the points are thrown. Best fix is to gap the rails about 1/2" behind the frog, and your problem should be solved.

Lou