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Question about not-in-use engines and constant DCC track voltage ....

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  • From: Michigan
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Question about not-in-use engines and constant DCC track voltage ....
Posted by Over50 on Monday, November 19, 2012 11:09 AM

A prominant MR author wrote in an article he electrically isolates sidings and engine "parking" track with a nomally open push button switch to prevent not-in-use engines "baking" with the constant track voltage with DCC. Being new to DCC this is the first I'd read of any concern about idle engines and the constant track voltage.

Is it really necessary to do this to prevent not-in-use engine damage from the constant track voltage with DCC?? 

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Posted by floridaflyer on Monday, November 19, 2012 11:35 AM

The short answer is no, however I do isolate my sidings to cut power to my not in use locos. 

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Posted by Over50 on Monday, November 19, 2012 11:43 AM

I'm confused....if it isn't a problem then why do you isolate your sidings to cut power to your not-in-use engines?

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Posted by richg1998 on Monday, November 19, 2012 11:44 AM

The decoder is just idling when parked. No current to the motor.

Now, if the loco has no decoder and the DCC controller can run one DC only loco. That is a different story.

There is a constant AC voltage which causes the motor armature to buzz and that "might" cause damage.

I suspect some people just do not want to take any chances or they use a starter system with maybe only a two amp DCC controller like my NCE Power Cab that cuts out at about 1.8 amps.

Our club with a five amp system no problem.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

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Posted by cacole on Monday, November 19, 2012 11:49 AM

Our large HO scale layout has all tracks on all the time (when in use), powered by DCC, and we have never had any problem with leaving an engine on a powered siding PROVIDED the decoders have been set to disable DC operation.

You should never leave a DC powered locomotive sitting on a DCC powered track for any length of time because that can cause the motor to overheat.

I have heard one claim from a person who is not a metallurgical engineer, that leaving a locomotive sitting on a DCC powered track for an extended period of time can damage the wheels because of electrolysis between the two types of metal; however, I don't lend much credence to this.  In my opinion the locomotive would have to sit for a year or more with power applied 24/7 for there to be any danger of electrolysis.

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Posted by Over50 on Monday, November 19, 2012 4:03 PM

I'll be using the Digitrax 5A Super Empire Xtra system. I bought (4) new DCC engines and will convert my best running DC engines to DCC - point being - I won't be running any DC engines on this new layout, which by the way is for my personal use so no multiple operator concerns..

This said, being new to DCC I had the impression you can't run a DC engine on a DCC system because of the constant 14v on the rails. Apparently the learning curve is greater than the pro-DCC "simple to use" literature I've read leads one to believe.... (wink)....

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Posted by rrinker on Monday, November 19, 2012 4:40 PM

 Guess that depends on who's literature. Digitrax and Lenz support running a non-decoder loco, using address 00. The others do not. It's not the greatest thing but it does work. Not something you should rely on.

 Out club layout has a large engine facility, at bigger shows, where lots of people show up, there can be two dozen locos idling there, for hours at a time, several days in a row. No problems. A good reason to have cutoff though, is to prevent inadvetant movement. It's not too hard to key in the wrong address (ever dial a wrong number?), and there is something in humna nature that if you turn the throttle on and what you are looking at doesn't move, you turn it up some more. and more. If you keyed in the wrong address, that happens to be the address of a loco that was parked on the other side of the layout out of sight, it now may be rocketing along on a collision course with another loco or even worse, on a trip to the floor. Particularly important in hidden staging areas - by the time you see or hear the errant loco, it may be too late to prevent damage.

 Is it required? Absolutely not. No harm will come to a loco with a decoder sitting on powered track, even for extended periods of time. The current draw when no power is going to the motor is miniscule. But - is it a good idea to have shutoffs? Yes.

            --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by wjstix on Monday, November 19, 2012 4:44 PM

Some older sound decoders make idling sounds anytime there's power to the track, even if they aren't selected. It's nice if you have a couple of those in say an enginehouse or service area to be able to cut power to the track so they're silent.

Stix
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Posted by Over50 on Monday, November 19, 2012 5:26 PM

Really appreciate all of the replies. Cleared up a couple of unknowns for me. Not a big deal to isolate my engine house and other parking tracks with a toggle. Again, thanks to all for the help! Thumbs Up

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Posted by locoi1sa on Monday, November 19, 2012 5:27 PM

If any of your locos have light bulbs instead of LEDs the bulbs will get very hot and could possibly melt the shells. A bunch of sound decoders sitting and idling away with the random sounds can get annoying. One time I stopped a 6 loco consist of RS locos at the fuel rack on the lead to the turntable. I didn't realize until the first loco was in the pit that I left the throttle on speed step 1. It took about 10 minutes for the locos to travel the 15 to 18 inches to the pit. One of our club members did the same thing inside the roundhouse until the rear wall gave way. Now the house has a rotary switch to select the track. Sometimes a decoder can get scrambled when a short occurs. The earlier version of the clubs Lenz system allowed broadcast programing. One member wanted to add some momentum to his loco on the main but ended up broadcasting some serious momentum into every loco on the layout.

  A simple on/off toggle in one feeder would suffice. The normally open push button would be a pain to hold and throw turnouts and work the throttle. The rotary switch on the roundhouse tracks works great. It only allows one track at a time to be powered. We will be installing another rotary switch on the turntable leads and another in the larger yards too. Most of our sidings are power routed through the switch machines. If one turnout is thrown for the siding the siding is powered. The longer passing sidings are not.

         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!

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Posted by csxns on Monday, November 19, 2012 6:53 PM

rrinker
Guess that depends on who's literature. Digitrax and Lenz support running a non-decoder loco, using address 00

Have seen this done at a train show,somebody bought a old Model Power loco and wanted to see if it ran so they ran it on a Digitrax address 0,i liked what i saw,now before i go out and buy a 500 dollar Digitrax Wireless will i be ok in running two DC locos with this Digitrax.

Russell

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Posted by locoi1sa on Monday, November 19, 2012 7:11 PM

csxns
Have seen this done at a train show,somebody bought a old Model Power loco and wanted to see if it ran so they ran it on a Digitrax address 0,i liked what i saw,now before i go out and buy a 500 dollar Digitrax Wireless will i be ok in running two DC locos with this Digitrax.

No. Only one DC loco at a time. I would not do it for long either. Zero stretching has been known to burn up DC motors. Weak magnet open frame motors will rob a whole lot of power from your DCC system and the motor will not last but an hour at most.

         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!

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Posted by csxns on Monday, November 19, 2012 7:13 PM

locoi1sa
Only one DC loco at a time. I would not do it for long either. Zero stretching has been known to burn up DC motors. Weak magnet open frame motors will rob a whole lot of power from your DCC system and the motor will not last but an hour at most.

Thanks a lot.

Russell

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Posted by rrinker on Monday, November 19, 2012 7:14 PM

csxns

rrinker
Guess that depends on who's literature. Digitrax and Lenz support running a non-decoder loco, using address 00

Have seen this done at a train show,somebody bought a old Model Power loco and wanted to see if it ran so they ran it on a Digitrax address 0,i liked what i saw,now before i go out and buy a 500 dollar Digitrax Wireless will i be ok in running two DC locos with this Digitrax.

 Not together, there is only one address 00, so both would move at the same time. Depending on the make and type of motor, they may or may not run at the same speed together, and there's no way to adjust them to speed match like you cna a DCC loco.

 I've had mixed results, old Athearn Blue Box locos with the gold motors make a hell of a racket, because the magnets are not actually fastened in place in those motors. Remove the top and bottom brush clips and you can completely disassemble the motors to component parts (don;t do this, it weakens the magnets, resulting in poor running and higher current draw). An old Bowser PRR T-1 kit that I couldn't get to budge on a DC powerpack - the heavy duty pulse effect of runnign on DCC address 00 got it moving and after getting some running in it gradually loosened up.

 In neither case did the motors get hot, but I also didn;t leave them sitting stopped and not moving for hours.

                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by MisterBeasley on Tuesday, November 20, 2012 7:52 AM

I have shutoff toggles for the stall tracks in my roundhouse, and for the tracks in my long storage/staging yard.  A lot of sound engines will idle loudly, so it's nice to be able to totally shut them down without having to go through a shutdown sequence.  Older Soundtraxx decoders don't have a shutdown, and even the newer ones will come back to life after a power off or short recovery.  I also like to be able to kill an entire siding when I have a lighted passenger train there, just to save on power.  And then, some engines and passenger cars use incandescent bulbs - might as well not burn them if I forget to shut them off.

On my Lenz system, I can run DC engines as Engine Zero.  This goes back to "running the track" for DC engines.  They all move at once, in the same direction.  (Think clockwise-counter-clockwise, not forward and reverse based on how the engines is pointed.)  And, you can't run a DC engine through an auto-reverse loop in DCC.

In my experience, the best thing about running a DC engine on a DCC layout is that it will inspire you to put a decoder in and stop doing that.

It takes an iron man to play with a toy iron horse. 

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Posted by Over50 on Tuesday, November 20, 2012 11:47 AM

MISTERBEASLEY.... Yup, I already decided no running DC engines. Being new to DCC the issues of parked engine sounds and lights running didn't occur to me. So much for "less wiring" with DCC vs DC. I had track power toggles on all my sidings, engine house track and staging yards with my DC system, meaning the joy of all the extra wiring under the bench work pulled back to a control panel.

The more I learn with this transition to DCC the only often hyped "less" is reverse loop auto reversing. Convenience of operation after all the wiring is done, well, that's a definite positive for sure, except for the CV programming learning curve required to enable a lot of it....and at my age the adage you can't teach an old dog new tricks is more than a laughing factor. Suffice to say the more I get into this the more overwhelming it's becoming..... 

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Posted by cuyama on Tuesday, November 20, 2012 1:06 PM

Over50
CV programming learning curve required to enable a lot of it

Thousands of people have layouts where they run multiple engines in DCC without ever having manually changed one CV. Ever.

For "silent" DCC, similar to the functionality you had in DC, there would be no need for cut-off switches, either. There are many layouts where DCC-equipped engines sit on powered tracks for months with no ill effects.

Folks often contrast the complexity of multiple independent engine control DCC plus sound with single-cab non-sound DC, ignoring the complexities of wiring for multiple independent engine control in DC. DCC provides much more functionality for the equivalent or less wiring complexity.

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Posted by cuyama on Tuesday, November 20, 2012 1:37 PM

By the way, if you don't have a good general guide to DCC, a book like Basic DCC Wiring for Your Model Railroad might be helpful.

Best of luck.

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Posted by rrinker on Tuesday, November 20, 2012 5:14 PM

 The only wiring back to the 'control panel' (which is a misnomer, there is no centralized control panel on my layout) are the 3-wire plug-in cords for my servo motors that attach to the Tam Valley controllers which are mounted on the fascia ('control panel') adjacent to the turnout it controls.

 If I was nuts I wouldn;t even need that, as I could operate the turnouts via the DCC controller, but that is horrible awkward on EVERY brand of DCC.

 Avoid the more complicated parts of CV programming - get JMRI.

           --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by The_Ghan on Wednesday, November 21, 2012 6:02 AM

If you have installed interior lighting in your passenger cars then putting your sidings on a separate circuit with either a toggle or a relay can be a lot cheaper than fitting a function-only decoder to each passenger car to control the lighting.  For example, I model Japanese N-scale passenger trains.  I have over 50 consists.  Some of those are 16-car sets, but most are around 8-10.  Although most EMUs require 3 decoders because the motor is often a middle car, I'd still be up for an extra 5-7 decoders per consist ... about $4000 all up.

Just something else to keep in mind ... Big Smile

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Posted by Over50 on Wednesday, November 21, 2012 12:15 PM

THE_GHAN...  Only have one set of 60 ft. passenger cars and no plans to install interior lighting so it's not a factor for me. My prime interest and time period is 1950's coal and freight hauling with a 5 car passenger train just running around the layout when I show my layout to visitors...

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Posted by locoi1sa on Wednesday, November 21, 2012 4:28 PM

You do not have to isolate every siding. Just the ones where you park your engines or trains. Round house and staging tracks would be the most logical choices.

        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!

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Posted by The_Ghan on Wednesday, November 21, 2012 8:19 PM

Over50: you're lucky ... in-car lighting isn't a problem for you ... Smile

Cheers

The_Ghan

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