running DC engines on DCC EZ Command?

[piggy back]

Can I run a concest of say 2 or 3  Analog DC engines using my DCC EZ Command controller?

[Trainman203]

DC motors run on fluctuating voltage to change speed.  The motor relies on constant polarity of the current and s magnet to be able to rotate.

DCC puts a full consistent AC voltage onto the track.  The currrnt polarity changes with the "cycle " , typically 60 per second in the US.

Imagine what that does to a DC motor.  It is trying to reverse direction 60 times a second.  At full speed.  Imagine what that would do to a car.

Short answer: no.  Or you get 😱💥💥😭.

[jward]

DC locomotives do not consist the way dcc locomotives do. To run more than one DC locomotive, you simply couple them together and run them. DC locomotives on DC track will all run the same direction. That is why block control came about, to isolate sections of track so you could independently control more than one DC locomotive.


What Trainman said is true. Running DC locomotives on DCC powered track is not a good idea. It van shorten motor life, and even burn out motors. It's especially bad if you leave a DC locomotive sit  with the DCC power on the rails.

the takeaway: Even if your system is capable of running a DC locomotive, do not do it. Power the track with a DC controller to run these locomotives, or put a decoder in them for DCC.

[rich1998]

The AC component causes the armature to get quite hot where the brushes contact.
Some years ago I measured with an infra red temperature scanner. Both points get hotter when the loco is stopped and power is still on the track. Slightly cooler as the armature rotates.
If you insist on doing it, put the loco on a siding and switch off the power.
I use to do it with a MRC2K but gave the set away. It was like the EX Command. Both are starter sets.
I bought the NCE Power Cab.

Rich

[piggy back]

I was told you can run a DC engine on the EZ Command DCC layout as long you keep the engine moving you should be fine! It's letting it sit too long is when you run the risk of frying the motor?

[Trainman203]

DCC supplies a constant AC current to the track , around 14 V I believe.  How can that be not harmful to a DC motor, or allow speed control at all?  I'm not an electrical engineer, someone enlighten me.

[rich1998]

It can be harmful after an extended period of time. I already explained what is happening and what to do. The DC component will run the motor but the AC component will cause the oscillations.
With a multimeter on the rails, you will see DC voltage and AC voltage with the EZ Command. Simple enough if you understand basic electronics/electricity.
The NMRA I suppose came up with this because they new some might not want to change to DCC right away. There has been a lot of discussion about this over the years.

https://sites.google.com/site/markgurries/home/technical-discussions/dc-loco-on-dcc

I had the MRC Command 2000 some years ago. I could run a tender drive Bachmann DCC 4-4-0 loco and bring an 0-8-0 DC Winans Camel up as a pusher up a hill, no problem. Disconnect and run the pusher back down to a siding and turn off the power. It was noisy. The Camel was a bashed MDC old time 2-8-0. Over size drivers though.
Some years ago I was told I could not do this but I did it anyway.
Rich

[Len]

To me running a DC loco using a DCC system is one of those things that falls in the, "Just because you can do something, doesn't mean you should.", categories. When using address '0' on a DCC system for a DC loco, the decoder is still putting out a Pulse Width Modulated DC (PWN) signal. Which is essentially a square wave with a fixed peak voltage that has it's width increased or decreased to control the motors speed.

PWN has been used for years in Large Scale, where motors are big enough to handle the extra heat generated. But the extra heat can be a problem in smaller scales like HO, N, and Z. Particularly when the loco is stopped. Power isn't actually removed, like in a DC system, the pulses just get so narrow there's not enough voltage to spin the motor. But the pulses still cause the motor to heat up, enough to cause damage in N and Z locos if they are left sitting with power on the track for too long.

Len

[Trainman203]

What is "basic electronics/electricity " may not be very " basic " to everyone.

I've nrver heard before that DCC (apparently) puts DC on the rail as well as full voltage AC.  Is it variable voltage?  How does it control speed of a DC train?

I love electric trains.  I just don't like electricity.  I've nrver had a layout  with more than two wires to and from the power source.  My present one has a 50' mainline and works fine.

[rich1998]

From what I read quite a few years ago, the NMRA came up with the idea to do this. Someone else might know different.
It is suppose to be temporary anyway. Got me fully into DCC.

Rich

[jward]

I have a Percy that is made the mistake of letting sit on DCC powered track a few years back. It did ruin the motor. Percy is a small locomotive with little room to dissipate heat, and with a small cheap motor. If I had to do it all over again, i'd have taken it apart and installed a Z scale decoder before running it on my layout.