# power - number of locos



## swiggy (Jan 25, 2010)

how many locomotives can I run on DC power? I also have 6 lights and 4 switches connected to the acc. on the transformer. I think I am underpowered? I can run two locos for about 15 minutes and the transformer begins to get warm, not hot. Do I need a second power pack/transformer? Is there an alternative way to power accessories? 

thanks


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## Big Ed (Jun 16, 2009)

swiggy said:


> how many locomotives can I run on DC power? I also have 6 lights and 4 switches connected to the acc. on the transformer. I think I am underpowered? I can run two locos for about 15 minutes and the transformer begins to get warm, not hot. Do I need a second power pack/transformer? Is there an alternative way to power accessories?
> 
> thanks



What kind of transformer do you have? It's normal to get warm when using it. But not hot.
What scale are you running HO? Or N?

You could get another small transformer to power the accessories.


edit......
I see your running HO. Right?


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## tkruger (Jan 18, 2009)

I could run two small locos on my stock Bachmann transformer when they only were pulling a few cars each. I now have an MRC 700 Power and Sound that I have run a 12 car train and an 8 car train at the same time with an incline etc. The MRC does not even get warm. Allot has to do with the size / quality of the power pack you have. Adding several power leads to the track will also help greatly.


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## swiggy (Jan 25, 2010)

HO scale, athearn stock transformer. Should I get a cheapy off e-bay?

**important: I may be going DCC soon**!

I have one extra power lead in this layout

http://www.youtube.com/watch?v=Uyl-MWxPboM


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## tkruger (Jan 18, 2009)

If you are going to DCC soon I would hold off. The worst you will do is burn out your existing power pack. If you do that then you would have to replace it anyways. The stock ones are known to get warm with even one train running. 

From your video the thing that I would be concerned with is if the locomotives are matched. If they are not geared the same and pulling with equal speed then one could cause the other to wear out prematurely. The slower locomotive will cause the faster one to work harder than if it was alone. With DC it is often better to run a Dummy with a single loco. I have had two identical locomotives from the same manufacturer that pulled different due to the amount of wear on each. A strong engine should be able to handle that train on its own. The cars may have to have their wheels / axles upgraded to create less rolling resistance. 

With DCC the locos can be matched since they are controlled electronically with a speed controller and not by the current sent to them.


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## swiggy (Jan 25, 2010)

great info. thanks tkruger!! The locos in the vid are an Athearn gp60m and a Bachman gp40. The Athearn is DCC ready and runs barely faster than the Bachman (not DCC ready, soon not to be used much), and the Bachman pulls grades slightly better. 
Now with DCC can I hook three locos onto a long train? I like trying to max out the length without over stressing the engines - I have read bad things about traction tires - I would rather just get good engines
thanks


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## tankist (Jun 11, 2009)

tkruger said:


> With DCC the locos can be matched since they are controlled electronically with a speed controller and not by the current sent to them.


with that one will need to match their speed tables, meaning that at every step through the programmed curve the locos should have similar speed. quite a job i hear.

note: newest decoders have BEMF speed stabilization feature. it might be enabled by default. when MU'ing locos BEMF should be turned off as locos will try to compensate over any slightest speed mismatch - bad.


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## swiggy (Jan 25, 2010)

WOW! sounds like a difficult goal to achieve. So with DCC I can run three smaller trains at once - no mating. I never knew how much resistance there is with plastic wheels. Ran the 
gp60m with all metal wheels on 10 cars - slowed slightly up the grade, but a major difference. no more plastic for me. (I know this is well known, sorry i'm a newby)

thanks again everyone - VIDEO COMING

http://www.youtube.com/watch?v=-6tj_aI7VN4


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## jzrouterman (Nov 27, 2010)

*number of multible engines*



swiggy said:


> how many locomotives can I run on DC power? I also have 6 lights and 4 switches connected to the acc. on the transformer. I think I am underpowered? I can run two locos for about 15 minutes and the transformer begins to get warm, not hot. Do I need a second power pack/transformer? Is there an alternative way to power accessories?
> 
> thanks


The answer to your question would actually be two different answers. First, it largely depends on the transformer you use. With a large enough transformer, you could run up to 4 or 5 engines at a time for however long you wanted, without having to worry about the transformer burning out. Second, it also depends on what brand of engines you're running, as some pull quite a bit more power than others. 

I run Atlas engines together. The power packs I use are two MRC 9500 power command transformers. These put out an enormous amount of power and were designed to run multible engines. Each has two gauges, telling me how much power the engines are actually pulling, aqainst what the existing track power is while doing so. Plus, if there's ever anything wrong anywhere either with the track or with my engines, my gauges will tell me immediately. With each of these transformers I can run 4 or 5 engines together. However, because of my layout being only a 4 x 8, I normally just run two engines with each freight as I don't really have the room to run any more than that while still making the entire scene look real.

Atlas, and Athearn Genesis engines are the easiest to run with multible engines, as these use the least amount of power. They can also be mixed together and run with one other with no problem at all. Some Katos don't draw much power either, but then a few do. Some of the new Athearns can also be run with either each other or with either Atlas or some Katos or some Athearn Genesis without any problem as well. However, all of the older Athearn engines pulled a large amount of power and the results with them varied. The same with some of the Protos because some of them draw a lot of power as well. 

Like some of the others here have correctly pointed out, the engines that draw a lot of power will put a drag on those that hardly draw any power at all. And if this is done for a long enough period of time, some of these engines could be damaged because of it. 

So in the final analysis, I would have to say if you want to run multible engines for however much time that you want without damaging either the transformers or the engines, start with the purchase of a transformer that was built to do just that, running multible engines. Then experiment with your engines. Then depending on the brand or brands you run together, this will be the final deciding factor of how many of them you'll be able to run together at one time. 

Be advised though, there are some models of different brands that just cannot be run in multibles, not because of what transformer you're using, but because some engines will just simply fight against one another when being run together. This is particularly the case with some of the lower end models. Unfortunate, but true.

~Routerman


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## tkruger (Jan 18, 2009)

Great explanation jzrouterman. Another thing to consider if you have any older or used equipment is that two identical engines may not run the same depending on the wear they have. I have two Athearn GP 35 Blue Box locomotives. One pulls great, the other grinds and runs slower. The grinding one cannot pull as much either. If you were to look at them you would think they are identical.


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