I recently tore down my old HO, DC railroad with atlas turnouts and rebuilt with Peco code 83 Insulfrog turnouts and made the switch to DCC, thus new to both Peco and DCC. As I have been getting things up and running, I have a couple of #5 turnouts which are causing the DCC system to short out.
After a lot of time, I finally figured out that it was certain, lower end cars with metal wheels that were causing the short at the frog rails as they barely touched, or at least got close enough to cause a short, the other frog rail on the insulfrog turnout (I saw this mostly with the lower end Walthers cars). So, I switched out wheels to intermountain and now they work great. Is this a common problem and are there certain brands that I should just plan to change the wheels on?
The issue that is causing me the most grief are my old Athearn "blue box" cars that have the metal weight under the floor (I have had these cars for 30 years now). I have changed all of the wheels to intermountain, about half work just fine and half still cause the short. Do I need to move the weight into the car instead of under it? Is this also a common problem?
Finally, would I be better off to cut a gap on the turnout and insulate it? If so, how would you do this?
Thanks for your help and knowledge.
I run N Scale and it happens all the time on PECO insulfrogs. Older wide tread metal wheels will make brief contact. DCC circuit breakers are much more sensitive and fast to react then analog DC breakers. That's why that brief short doesn't show up on analog power. it is cleared before the breaker gets chance to trip. Electrofrogs work better because thefrog rails match phase so no short.
Wheels with narrower treads are more prototypical. Also check the guage on your wheels. Many times simply setting the guage on your wheels will help.
Martin Myers
Both insulfrog and electrofrog switches have problems when switching from DC control to DCC. With the insulfrog switch the problem is metal wheels on locos and cars bridge the frog rails causing a short circuit. Using some non-metalic nail polish at the spot where the short occurs to insulate where the wheels bridge the frog works good, but will have to be reapplied occasionally when an abrasive track cleaner is used or from normal wear.
Two things:
I have some of those older Athearn cars with the aluminum floor that also doubles as the car weight. I used 33" Rebbox wheels (#1025). The 36" wheels are too large and will make occassional contact with the metal underbody. Even the 33" may come in contact occassionally. So I sprayed a couple coats of "liquid electrical insulation tape" (made by GB - Gardner Bender). This may have to reapplied at some time in the furture if any wheel rub eventually wears through.
The other thing I recently discovered (due to too much current surge at track power turn-on) is to change an option switch setting on the command station/booster. In my case this is a Digitrax DCS100. Setting option switch 18 to Close extends the booster short circuit time from 1/8 second to 1/2 second. This might be just enough additional time to eliminate or at least reduce the number of short circuit occurrances.
I did the change of the booster short circuit reaction time on my DB 150 and my clubs DCS 200 to 1/2 second. No difference in occurances. Also tried auto brake light bulb in series with the A rail. Nail polish did the trick.
Thanks for the suggestions. I am going try nail polish and see what happens. I am also going to wrap the metal weights w electrical tape and try that.
Srwill2,
The stamped steel weights should have absolutely nothing to do with Your problem...unless of course, Your metal wheel set flanges/trucks are touching them, which is not a good thing either, wrong size wheels/trucks. Been using Athearn BB cars from the 50's, never incountered a problem with them causing any kind of short.
Do The nail polish tip....
Take Care!
Frank
In this case, the weight has nothign to do with it. However, when metal trucks were more common, it did sometimes cause problems. Mounting screw through metal truck into car frame touching metal weights. Insulated wheels on one truck on the right hand rail, on the other truck, on the left hand rail. You now have a nice conductive path from teh left rail to the truck through the screw to the weight to the other truck's screw, truck frame, and into the right rail. But this would generate a continuous short anywhere on the layout, not just at the turnout frogs.
The issue indeed is the super narrow strip of plastic insulator used, and the wheel tread bridging the gap.
--Randy
Modeling the Reading Railroad in the 1950's
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