On my old DC layout I had a couple of storage tracks where I would park my unused locomotives, the wiring was very simple, one rail was live and the other was isolated. When the engine stored was needed for operations a spst activated the isolated line and the locomotive would start up ready for use.
On storage tracks with a DCC layout do I use the same electrical layout with the spst or do I need to wire the tracks differently?
Just now sure how sensitive DCC decoders are to electrical power.
Your plan will work just fine. Since one rail is 'dead', there is no electrical path to complete the circuit and the decoders will be fine.
Dyed-in-the-decoder DCC fans will tell you that you don't need to isolate the storage tracks - just do whatever electronic magic is needed to put the decoder to sleep.
BUT!!! Using a simple SPST to kill the track dead will prevent any misguided youngster or senior moment from moving the train you wanted to stay where you parked it. If, like me, you have an extensive netherworld, having a semi-controlled train wandering around under the mountains has a disaster potential that is well worth avoiding.
(Aside to those who might be getting confused, my little slice of Japan is still operating analog DC, MZL system - and no change is contemplated.)
Chuck (Modeling Central Japan in September, 1964)
The SPST will work just fine. Flip it on, locos can be moved because the track is powered. Flip it off, locos cannot be moved because the track is unpowered.
But the bigger issue is DCC. Since your layout is DCC powered, even in the absence of a SPST, the locos aren't going anywhere unless you call them up by addressing them on your throttle.
So, I am not sure what the SPST adds except another layer of protection. Now, you have to flip the SPST on before you can call up a loco address.
Personally, I do not see the need for an SPST in this situation. I have locos parked all over my layout. When I turn on the DCC command station, nothing happens until I begin accessing locos by calling up their addresses on my throttle.
Rich
Alton Junction
tomikawaTT Dyed-in-the-decoder DCC fans will tell you that you don't need to isolate the storage tracks - just do whatever electronic magic is needed to put the decoder to sleep. BUT!!! Using a simple SPST to kill the track dead will prevent any misguided youngster or senior moment from moving the train you wanted to stay where you parked it. If, like me, you have an extensive netherworld, having a semi-controlled train wandering around under the mountains has a disaster potential that is well worth avoiding. (Aside to those who might be getting confused, my little slice of Japan is still operating analog DC, MZL system - and no change is contemplated.) Chuck (Modeling Central Japan in September, 1964)
Chuck, with all due respect, if a misguided youngster knows enough to access a loco by addressing it, the kid can flip the SPST to power the track unless the SPST is hidden and unknown to the little brat.
As far as a senior moment is concerned, I am not sure what a SPST provides unless the parked loco is on a storage track at the end of the layout with nothing to stop it from hitting the floor. Once the SPST is thrown, the same problem exists.
It seems to me that the SPST will only be useful in preventing parked locos from entering reverse polarity sections or moving from the programming track to the main layout. In general, locos parked on storage tracks on a DCC layout need no further protection from mishaps.
Howdy, Rich,
If you could see the schematic of my layout (where an out-of-control DCC train could result in a netherworld head-on between brass locomotives ) you'd understand my belt and suspenders approach.
As for our hypothetical little brat, he could be on the far end of the operating aisle and simply mis-key the address. Not a deliberate act, just another .
Since my 75th birthday is history, I have first-hand knowledge of senior moments. You should see how often I have to go back and correct mis-keyed words on this keyboard - and these keys are both bigger and farther apart then the buttons on a remote.
Finally, as a former aircraft type, I'd rather have too many fail-safes than too few.
The need for storage tracks is a result of not having all of my locomotives updated to DCC.
I still have a few locomotives that I want to run from time to time that will never get updated.
Plus I have a lot of lighted passenger cars that drain the system when not running.
don7 The need for storage tracks is a result of not having all of my locomotives updated to DCC. I still have a few locomotives that I want to run from time to time that will never get updated. Plus I have a lot of lighted passenger cars that drain the system when not running.
ahh, then the SPST would be appropriate, if not outright necessary.
tomikawaTT Howdy, Rich, If you could see the schematic of my layout (where an out-of-control DCC train could result in a netherworld head-on between brass locomotives ) you'd understand my belt and suspenders approach. As for our hypothetical little brat, he could be on the far end of the operating aisle and simply mis-key the address. Not a deliberate act, just another . Since my 75th birthday is history, I have first-hand knowledge of senior moments. You should see how often I have to go back and correct mis-keyed words on this keyboard - and these keys are both bigger and farther apart then the buttons on a remote. Finally, as a former aircraft type, I'd rather have too many fail-safes than too few. Chuck (Modeling Central Japan in September, 1964)
Hi Chuck,
Under those circumstances, I see your point.
I put such kill switches on all the stall tracks around my turntable, and on all the track of my storage/staging yard. Even in DCC, it's helpful. Along with lighted passenger cars, I have a few sound engines which don't have "shutdown" sequences, so to keep them quiet when non-operational, I need to shut down the track power.
It takes an iron man to play with a toy iron horse.
I'm with you MrB, for the same reasons.
For a real 'Fail Safe' system run all the SPST toggles through a 'Key Switch' and then nobody (young or old) can accidently throw a switch (unless you give them the key?).
-Bob
Life is what happens while you are making other plans!
don7: Your existing setup will work just fine, and you can leave all the "kill switches" normally on. You can remove all the switches, or leave them in for emergencies or maintenance.
Chris van der Heide
My Algoma Central Railway Modeling Blog
Awhile ago, I don't remember where, I read that the rationale for having kill switches to turn off power to storage tracks was to keep from "cooking" the decoder chip with continuous power to it all the time it sits for extended periods on a storage track.
Is there any basis for this? I'm in the process of wiring my layout and I had planned to put kill switches (SPST On-Off switches) on all my storage/staging tracks and roundhouse tracks where locos would sit for extended periods to prevent damage to the decoders.
How does one put the decoder into "sleep" or shutdown mode?
Thanks,
Bob
RFinch Awhile ago, I don't remember where, I read that the rationale for having kill switches to turn off power to storage tracks was to keep from "cooking" the decoder chip with continuous power to it all the time it sits for extended periods on a storage track. Is there any basis for this? I'm in the process of wiring my layout and I had planned to put kill switches (SPST On-Off switches) on all my storage/staging tracks and roundhouse tracks where locos would sit for extended periods to prevent damage to the decoders. How does one put the decoder into "sleep" or shutdown mode? Thanks, Bob
To Don7:
Per your suggestion, I went back and reread this thread from the beginning. There is nothing in it that addresses my question about turning off power to storage tracks to prevent damage (cooking) to the decoder chips, nor is there anything describing how to put decoders into sleep mode. Since I'm new to DCC, these may be questions that seem dumb to you more experienced DCC users, but I'd still appreciate an answer. I understand the safety issues that have been raised in the above posts!
Bob, my take of this thread that I started is as follows:
The general consensus was that the dcc decoders are not subject to damage if left on.therefore there is no real reason to use SPST switches.
For those who are bothered by the noise of the sound decoders you have the option of muting the decoders.
For those that were still concerned about the decoders being live you may turn off the decoders (go to sleep) by changing codes. Those codes would be in each of the sound decoders manuals.
It was felt that cutting the power with a SPST is a safefy issue,
A lot of posters indicated that they had tracks on their layouts, especially around the roundhouse and turntable facilities where they wanted to make sure there were no accidents and many of them had those tracks on SPST switches.
Note I mix DC locomotives on my layout so I need specific tracks where I can park my DC locomotives and not harm the motors with my DCC system. Especiallly at my roundhouse yard facilities where I have both DCC and DC locomotives sitting on the layout.
To my knowledge, a properly wired decoder sitting on a storage track for an indefinite period of time will not get cooked or fried.
Different decoder manufacturers have varying methods for shutting down sound and lights but, again, to my knowledge, there is not a CV to turn off a decoder completely.
A SPST can act as a kill switch to a storage track to cut off the electrical supply, and that will effectively accomplish what you are trying to do.
RFinch How does one put the decoder into "sleep" or shutdown mode?
This depends on the decoder. For QSI decoders, for example, the seqeunce is three double-taps of F9, or at least that's the way I do it. Tsunamis have a different seequence. On my Lenz throttle, it's done by pressing the Stop/Reverse key twice in quick succession, as I recall. Earlier L-series Soundtraxx decoders do not have shutdown sequences. F6 restarts both decoders.
Pretty much all sound decoders can be muted with F8. However, this isn't a "saved" setting, and the decoder will come back to life after a short or power-down.
I don't think there's a problem with decoders "cooking." This may have been a problem with earlier decoders, or perhaps its a holdover from the practice of running DC engines on a DCC layout. Some DCC systems allow this, and there have been a few reports of motor burnout from idling DC engines on a DCC system.
The only time I've seen a decoder get fried is if it somehow shorts out. Just sitting there idling will not harm it.
It's a good idea to always turns things off when you're not using it, but to put your mind at ease, we regularly have the DCC system continuously running for something like 8 hours at a time for open houses and monthly operating sessions and we don't turn anything off during. We have engines and decoders that have been operating on the layout for 10+ years.
When everyone goes home, we turn off the system, and then turn off everything right at the breaker panel.
Sorry I didn't respond earlier. I want to thank everyone for their input on my questions.
From what's been said above, it appears that a modern, properly wired decoder will not be damaged by being parked on a powered track indefinitely. This is going to save me having to install kill switches on all my storage tracks. I model in N scale, so I don't think I'll have too many sound decoders that I'll have to silence.
Thanks again for your help,