I am running a sound equiped loco on dc. My rolling stock has MT plastic wheelsets, but would like to convert to metal wheelsets. Is there any danger that a derailment, like at a turnout, could cause a short and fry the sound decoder?Thanks and,any other decoder protection info would be greatly appreciated as I am obviously old school.
I have some problems with metal loco wheels on Peco and Atlas insulfrog switches where the wheel bridges the insulation on the frog and causes a short. I have no cars with metal wheels but I believe they would also short at that point as visitors to my layout have found when running their metal wheel equiped cars on my layout. I have been using nailpolish on the frog points and have eliminated the shorting and have to reapply the polish once or twice a year. This is only with DCC on N scale. Never had the problem until I switched from DC to DCC. I have only one sound equiped loco with a POS MRC decoder so I can't help you with any info there. I'm staying with the plastic wheels.
The metal locomotive wheels will be the ones that would potentially scramble the decoder. I have never seen a fried decoder because of a derailment. What usually happens is a programing glitch that can be recovered with a reset. Decoders get fried mainly from a faulty installation or using the frame of the locomotive to transmit power either to the motor or from the rail to the decoder.
Will you be converting to DCC in the future? Proper wiring will prevent almost all potential damage from shorts. The breaker in the booster will shut down faster than you will detect a short. On DC the current is much lower. Most DC packs will never put out enough amps to fry or weld a metal wheel.
Convert your rolling stock to metal and you will be happy you did.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Metal wheel shorts will usually activate the circuit breaker on the DCC power source. I can't think of any scenario where they will damage the on-board electronics.
The usual sources of trouble are frogs and switch points, where a single wheel tread contacts both sides of the circuit at the same time. This shouldn't cause problems with a decoder unless it can be damaged by an abrupt loss of power. The shorting is confined to the tread and flange of a single wheel.
My handlaid specialwork has points that are electrically dead when open, eliminating the most usual source of wheel-back shorts. I also use hot frogs, and depend on some specialized track circuitry to keep trains from entering the trailing end of a turnout set for the opposing route. (Don't know how you would do this with DCC. In analog DC, MZL system, all I need is a couple of resistors and a diode.) If you're running over commercial specialwork, my methods won't help.
Chuck [Modeling Central Japan in September, 1964 - in twice-N scale (1:80, aka HOj)]
Most decoders get fried if wired wrong at the outset or where the decoder touches part of the metal frame, not because of derailments.
Go with metal wheels, you will be glad you did. Plastic wheels are dirty and prone to derailments.
Rich
Alton Junction
I guess if you want to feel comfortable switching to metal wheel sets consider this. Between the posters here there are probably thousands if not tens of thousands of pieces of rolling stock with metal wheel sets. I have yet to see anyone even consider a decoder problem because they had them on rolling stock. The only negative thing I've seen was the sound increase from using wheels and hearing the clickity clack at rail joints. I personally like the sound of metal wheels over plastic. There are other benefits with metal wheels and can be found searching the forums.
I'd jump in and switch if I were you. don't forget to pick up a truck tuning tool while you're at it.
Springfield PA
Peco I can see, the insulated section of an Insulfrog is a very short section, and I can see how wheels can bridge the insulator and cause a short. The advantage is, the unpowered section is so tiny you should never have a problem with loss of contact. But for metal wheels to short an Atlas turnout you must have some very out of gauge wheels. There's so much insulated area that short wheelbase locos or those that pick up with only 2 wheels on each side can often stall due to lack of power - making it more cticial to provide frog power fort he Atlas turnouts. There's just no place that the opposite polarity rails come within a wheel tread width of each other, at least not on the Custom-Line numbered turnouts with metal frogs.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
The insulated section on the Atlas N Scale Insufrog switches is about the same as on the Peco's. They are different than the HO versions. Metal wheels on cars will do the same thing as the loco wheels to create a short at the frog points.