Recently, and (so far)successfully, changed over to DCC. With assistance of guys here and Digitrax tech person, I programmed an address for a pair of F-units; and changed the NDOT for one of the units. Also 'programmed the "00" address for all other DC/analog locos... And!,TADA! operated both DCC and DC/analog locos simultaneously on same track. The DC/analog locos "sing"; the "singing" changes during operation. I think I read somewhere that this "singing" is a response of the DC motor in reaction to the constant AC current in the rails. Okay... Does this damage; and to what extent does this damage the DC/analog locos' motors??
Yes, there's a good chance that will damage the DC locos by overheating the motors in them. How quickly that will happen (if at all) depends on a number of factors.
Running one for a short period, like a quick test run, shouldn't hurt it, but any more than that is a risk you really don't want to take.
I've never burned one up but have heard a few stories about it happening. They will run hotter and from experience, noise and heat aren't good for electric motors. The buzzing is due to the AC. The way zero stetching works, that buzzing will reduce as the train is speeded up. They may be fine when running. At idle, the buzzing and heat generated is at its worst. This is because instead of getting positive on one connection and negative on the other with DC, the motor is reversing direction thousands of times a second. Now you know why it's call Alternating Current.
Best practice is to install decoders as soon as possible. They run better and you can actually get the full advantage of DCC. If running analog engines on DCC address 00, remove them from the track when not running or if possible, park them on track that is switched off.
Martin Myers
Below is a link that explains this issue.
http://members.shaw.ca/sask.rail/dcc/DCC-waveforms/DCC_waveforms.html
The point where the brushes contact the commutator segments gets quite hot when the motor armature is not turning. The armature is oscillating a slight amount because of the AC. The same spot tuns cooler when the armature is turning. A few years ago I did some measurements with an infra red temp scanner.
Those who do this have a siding they can turn off with a toggle switch. Usually a single pole switch will work. Some prefer a two pole switch. Your choice.
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.
In a DC locomotive, the rails provide the power directly to the motor through the frame and loco wiring. With DCC, the track provides power to the decoder. The decoder "decodes" the power and control signals from the track, then provides the power to the motor.
What the decoder installation does is breaks the electrical path from the track to the motor, and inserts the decoder inbetween them (track and the motor). That is why the motor brushes need to be isolated from the frame of the locomotive. The decoder then puts out the DC voltage to the motor to make it (the motor) run, without being connected to the track.
Less heat is generated and the DC motor does not need to be replaced.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Georgia Flash The DC/analog locos "sing"; the "singing" changes during operation. I think I read somewhere that this "singing" is a response of the DC motor in reaction to the constant AC current in the rails.
Does this damage; and to what extent does this damage the DC/analog locos' motors??
As I am not willing to fry motors in a real experiment to get real scientific answers, I rely on basic physics. I ask and answer the question, how does one demagnetize an iron bar? One answer is to put the magnetized iron bar into an alternating electrical current field. My opinion is that the high frequency DCC currrent that makes the motors hum is demagnetizing the magnets. Fortunately model train motors aren't just generic iron bars they are much more sophisticated, so they won't demagnitize as quickly as soft iron, but I still think as a result they will get weaker and weaker. Weak magnet yields weak pulling locomotive, until eventually there won't be enough magnetic energy left to turn the motor.
So my short answer is, Yes I firmly believe the hummm will harm the motors. I advise against using a DC loco on a DCC system.
Well, Looky here. I found one of the threads
http://cs.trains.com/mrr/f/88/t/105396.aspx
That was over 8 hours just sitting there cooking. What is needed now is a test loop and have one RUNNING and see how long it lasts. I suspect many many times longer than 8 hours, because it wouldn;t be sitting there cooking the same windings continuously. I've test run many locos using address 00 and never had a problem. The longest run one was probbaly a Boswer PRR T1 kit. It had never been run before, and the MRC DC pack I had would just trip the breaker when I tried it, so I put it on the DCC track powered by my Zephyer, and after a few false starts where it tripped even the 2.5 amp breaker, it finally started running. A bunch of laps around the 8x12 loop and it was going pretty good, so I physically turned it around (it was going clockwise so all right turns - flipped it around to bend the mechanism to the other side) and ran it for a while in the opposite direction. After a bit of break-in, it would start up fairly smoothly. Not much buzzing, that heavy cast meal boiler shell muffled any motor noise. Loudest were AThearn Blue Box - the tan motors are VERY loosely assembled and buzz like crazy.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I run an original Varney Docksider with a new can motor and no decoder with my Digitrax Zephyr Extra; also, an 80s brass steamer with original motor and no decoder. No hum when running although they softly sing when idle. I store them on spurs where the power can be switched off. When I run either I run it for several minutes at a time.
Dante
P.S. See avatar for steamer prototype!
Mine are all DCC now, but I ran several DC locomotives with my Digitrax Super Chief for over a year without harming them a bit. I always removed them when they were not running. The overheating only occurs when they are parked or running VERY slow.
Dave
Lackawanna Route of the Phoebe Snow
T.Zephyr:
Thanks for adding to/replying to my earlier post-thread. I get it: DC motors on DCC/AC current not good. So, I've begun the process of converting ALL locos to DCC. And, as a "DCC Newbie", I find this technology(?) fascinating; steepens my learning curve. Operating several trains simultaneously is a little scary, but fun; requires my full attention.
Thanks
Good that you asked. Not safe to make assumptions when it comes to DCC. There are far to many variables you find as you gain more knowledge.
Below are some couple good links to store in favorites and take your time looking around. There are many links in the below links also.
When you answer queries here, try to include links for those who do not know how to search for info. You can build a tremendous library in your Favorites list to help you and others. A picture is worth a thousand words.
You can find a lot on You Tube also.
http://www.mrdccu.com/
http://www.markschutzer.com/
http://www.members.optusnet.com.au/nswmn/index.htm
There are hundreds more sites about DCC and online suppliers.
Also be sure to visit TCS. Not only do they make very good decoders, they have install pictures for nearly every loco you can think of, which are applicable even if you don;t use their decoders. http://www.tcsdcc.com/