Does DCC make motors overheat?

[railfan]

I read this in the wikipedia article on how DCC works:

http://en.wikipedia.org/wiki/Digital...#How_DCC_works

"However, because the raw power contains a heavy AC component, DC motors heat up much more quickly than they would on DC power, and some motor types (particularly coreless electric motors) can be damaged by a DCC signal."

I have not read reports on this forum about any issues like this. Just wanted to see if anyone ever had a problem with locomotive motors getting hot with their DCC system. I recently aquirred a prodigy DCC system and will eventually set it up. I have N scale gear.


Mike

[WCWBrassHat]

Mike,

N scale or any other scale engines for that matter equipped with a decoder will not run hot on DCC. The problem comes in when a non-decoder equipped engine is left sitting on the track for a long period of time. If you place a non-decoder equipped engine on the track you will hear a hum. You can run a non-decoder equipped engine on some brands of DCC equipment (I know Digitrax does as I have Digitrax) on 00. Running a non-decoder equipped engine doesn't seem to cause the problem.

Glenn

[GenSet]

First off, DCC is a square-wave signal, NOT AC, which is a sine wave. One of many things Wikipedia has wrong. Secondly, DCC will never overheat a decoder-equipped engine.

[Selector]

DC motors on DCC track will heat up in the majority of cases, with some variance. The reason is that they don't have a decoder intermediary interpreting the signal and rectifying the current to a polarity which the motor can use efficiently. Instead, some systems allow 'zero stretching' which renders the DCC power approximate to a given polarity. However, it is only close, so the motor still gets excited in the opposite direction for brief fractions of a second, which causes the high frequency pitch squealing and squawking from the drivetrain.

[Cjcrescent]

One thing they have said does seem to be true, as I've seen it on other DCC wiring sites.

Some coreless can motors will overheat very fast on DCC. While I have one steamer with a coreless motor in it, it has run for over 10 years without a problem. However, one engine I had with another brand of coreless motor in it, ran about 5' before the motor cooked. I replaced it with another plain can motor and it now runs just fine. The one that is still running is a Cannon coreless motor, and the one that burned, IIRC was a Mitsubishi.

[Iron Horseman]

Originally Posted by railfan

I read this in the wikipedia article on how DCC works:

Remember wikipedia is a public update thing such that nothing found there can really be considered definitive or even necessarily true and correct.

I have not read reports on this forum about any issues like this. Just wanted to see if anyone ever had a problem with locomotive motors getting hot with their DCC system. I recently aquirred a prodigy DCC system and will eventually set it up. I have N scale gear.

As the others have said, If the locomotive has a DCC decoder in it this is not an issue since the decoder converts the DCC signal to DC for the motor.

If you are wanting to run a DC locomotive on DCC channel zero, yes there is a good chance you will ruin the motor. It doesn't have to be coreless either. Jeff Wimberly did some tests a few years back and fried HO Athearn motors in as few as 10 minutes. My advice to everyone is to NOT do this. If one wants to use DCC then one should put a decoder in all locomotives to be run (period).

[railfan]

Okay, that is some good information. Thanks!



Mike

[CSX Robert]

Originally Posted by GenSet

First off, DCC is a square-wave signal, NOT AC, which is a sine wave. One of many things Wikipedia has wrong. Secondly, DCC will never overheat a decoder-equipped engine.

DCC is a square wave, but it is also AC. AC does not have to be a sine wave.

[TrinityJayOne]

Apologies for going slightly off topic here but the Wikipedia article in question does state that the DCC signal is "a form of alternating current", which is technically correct. Nobody can dispute that the current alternates polarity. If anything the problem here is the assumption that "AC" always refers to a sine wave like the power coming from a wall outlet, rather than an abbreviation for "alternating current".


EDIT: Oops, beaten to it!

[railfan]

Math and science were always my best subjects in school and I built working motors and radios out of household junk for fun. I was frustrated to visualize how alternating current worked until I realized it is much like a piston in a cylinder going up and down.


Mike