OPERATING TRACK AND ELECTROMAGNETIC COUPLERS

Questions, questions. You say you are running TMCC but the engine uncouples on the uncoupling track. Does your engine have a slide shoe underneath for coupler activation?

You say the track section is just inserted into your line but not connected to any controller yet you state that none of the controller buttons are stuck down. Is the uncoupling track connected to its controller?

If it is connected to its controller then it is probably getting power from the track. Recheck the connections from the controller to the track section, it is very easy to get them connected backwards. If that is the case it is possible to activate an engine with a slide shoe.

Al

Thank you for your thoughts. The engine does not have a slide shoe for coupler activation. Sorry, when I used the term controller I was referring to the TMMC control module that the operating track could be connected to. Yes, it is simply getting track power.  The opeating track's controller, with uncouple and unload buttons, is connected to it and works fine for activating dump cars. That is, either the uncoupler activated type or the power shoe type. Clarke

OK, try this. Find a 1MFD NonPolarized 50 volt capacitor. Connect this between the two wire leads comming from the coupler and going to the rest of the circutry. You may need to order the capacitor from one of the sites listed elseware in the threads. Check the Electrical forum. Sorry, I would give you the web address but I don't have it. I don't think Radio Shack caries them. Something on the engine may be sparking when it goes over the track and causing a pulse that activates the coupler.

Al

Is it only one of your engines that does this when going over the operating track?  Are other engines ok with the arrangement?  What type of track are you using?  I'm thinking you got a saggy coupler on one engine that is coming too close to this operating track.  Or a hump in the operating track, or a combo of the two that is making the contact between the coupler on the engine and the operating track magnet.  But, that's just a guess.  I would tinker with it a bit.

You may have to separately power the uncoupling track.  I found that when I stuck a Fastrack uncoupling track in and used track power, it caused problems for the operation.  Separate power and all is well.

Hi folks, thank you for your posts.  They were all good ideas.  I tried separate power to the operating track, no luck.  I insulated exposed metal on the  bottom of the coupler, no luck. I was going to find  the suggested 50 volt capacitor. I tried another engine and the coupler held.  The only difference was the car coupled to the engine was a different      car than the one coupled to the engine that was giving me a problem. Please keep in mind it was not the car's coupler that opened, but the engines.    When I coupled different cars to the problerm engine, the engine's coupler stayed close.  So, the    problem appears to be with one particular car  coupled to the engine, even though the cars coupler stayed closed.  The only thing I can figure is different about the problem car is that it has a lot of brass in it. Your posts helped to keep me working on the problem.  So folks, thanks again and happy railroading.   Clarke  

Do you have other unusual track items near the uncoupling track?  Such as a switch or crossing.  I have had unexpected results with other special track next to an uncoupling track.  The results may depend on the car of locomotive length.  You can get the pick up rollers on an unexpected voltage or a sliding shoe can momentarly touch power in a switch while the other end is on one of the accessory rails.  I try to leave at least a full length of standard track either side of an uncoupling track.

I'd unplug the electrocoupler from the board and then test with the offending car.  If this is a mechanical issue, it'll still have the problem.  If not, it's an electrical issue, and the 1uF cap across the coupler leads is the next thing to try.

One other area to check is the pickup rollers on the engine and tender; make sure they are perpendicular to the center rail. I've seen rollers on new engines that are not oriented correctly and they will sometimes traverse the center rail and the control rail on a UCS track for a momentary short-more likely with wider rollers.

Thanks again folks.  For the time being I have shelved the offending car and the engine is running fine using other cars.  I agree on the idea of having separation before and after special tracks and have in all areas have at least one track section (usually more) before and after any special tracks.  The suggestion about correct alignment of pickup rollers is somwthing I will keep in mind.  I can see how a misalignet roller or shoe could cause a problem.  Clarkesr