DCS And Voltage Issues

If you're running three locomotives, you shouldn't be drawing enough to trip the Z4000 breaker even with the grade. As GG1Man said, look for a "resistive short" somewhere in/under the inclined track, particularly since you're seeing a steep voltage drop-off when the locomotives start-up.

You don't mention the length/weight of the train or whether lighted passenger cars are part of the equation, but that's another factor. That hits us sometimes at the club.

Thanks for the feedback. The two passenger trains are running on the same track. Both ABA Units are pulling six passenger cars each (10/12 are lighted). After moving around the passenger cars, I discovered that the problem goes away if I remove 2 of the lighted passengers cars. It's as if the engines/cars are now extracting more power (voltage) then they did prior to the incline, if that makes any sense. I unscrewed, and secured the track again, making sure that there were no screws or scraps making contact with the rails, and that there is a solid connection between the tracks, so I do not think it is track related. With that said, part of me thinks it has to be the track, since the problem did not exists prior to the incline. Would adding a lockon in the inclined area make any a difference? 

The locomotive will draw more power on an incline, and the additional will be dependent on the load it's pulling.

Appreciate all of your opinions. Would adding a lock-on to the incline help, or would it be irrelevant and not help boost the power. 

I would convert the passenger cars to LED lighting if they are no already or at least dim the bulbs in half with a diode in each car, then the total power used would be less of an issue. Depending on the make of cars,12 of them could use up to 100 watts by themselves,even more at 22 volts. On the incline,as John says,more power is used. I think you are exceeding the transformer capacity. Poor power distribution could also be an issue,perhaps a dirty track joint(s)

Dale H

I'm converting all my passenger cars to LED lighting.  That will basically remove them from the power equation, the cars draw around 40 milliamps each now.

This is an amperage issue, not a voltage issue. With the level track and the trains you had before, the transformer could handle the power consumption. Adding grades will increase the drag behind the locomotives, thus drawing more power. The combination of the grade+locos+lighted cars is now too much for the transformer, so it goes into overload. You see this because things are fine if you only run two engines or take out a couple of lighted cars - that is the difference that the grade makes. Adding additional lockons won't solve this issue (these are for keeping the voltage up so the train doesn't slow down or stop because of resistance/voltage leaks at track joints, wiring runs, etc). You need to either add more power, or look at reducing the load. Converting bulbs to LED's is a good suggestion but you should also look into powering other loops of track off of another transformer so the Z4000 is not taxed with all 4 trains.

Peter

I would think that the Z4000 is capable of handling four trains if the only significant load was the actual locomotive power and not the power required by passenger cars.  Even with separate transformers I'd seriously consider LED lighting.  For passenger trains, you'll basically drop the power consumption to half of the what the locomotive/cars now consume.

Thanks for the suggestions. I agree that LED lighting for the passenger cars would be the best solution, but I have no experience with wiring leds, and think I would create more problems. Regarding the idea of adding more power to the track, would that be achieved by wiring the track to an additional transformer (via a lock-on)? And if so, would that require a re-wiring of the dcs?

It might be interesting to audit the power consumption of your trains.  One at a time, record the Volts and Amps on the Z4000 display as the train runs on flat track and going up the incline.  Multiply the two to get the so-called "VA product."  So if 19V and 2 Amps then the VA product is 38 VA. The numbers bounce around but guess-timate an average.  Then note that a single Z4K output is spec'd at 180 VA (that's what mine says).  Presumably when you run all 3 engines with cars you'll see why the overload light flickers!

To your earlier point, I believe you'll find when starting up a PS2 engine (so the sound comes on) the VA products goes up by only a few VA.  You probably won't even see the difference as the numbers bounce around on the Z4000 displays.  That is, I think you'll see a much bigger jump in the VA reading when the train goes up an incline (vs. when starting up in DCS).

Dale's diode approach might a good compromise.  An LED-powered car will draw about 10-20% the VA of your present cars for the same brightness. The diode approach draws about 50% but will be dimmer.  So if you do an audit as above you can get an idea of whether these kinds of "savings" still leave you pushing the VA limit.

Or how about just removing a bulb or two from each car to lower the current?  Or if you have common bulbs perhaps you can replace them with some meant to operate at a higher voltage (say 24V instead of 18V or whatever) which would draw less current at 18V.  If your existing bulbs are socketed you might find some LED bulbs that plug right in (no wiring required) but this could be a spendy option to retrofit 10+ cars.

Hi Stan, your audit idea is simple and very effective. In fact I liked it so much that I thought I would provide the link to Scotts Odds and Ends. http://www.scottsodds-n-ends.com/LED_Lamps.htm

They have replacement LEDs that go into the standard sockets.

I'm sorry guys, I went on the Scotts site and all the white LED's are gone. They said that they still have red, green and blue.

I left them an e-mail question as to if and when the white will be available, I will post the answer when I get a reply.

I don't mean to be a wise guy here, but are you sure the wiring connections to your extra lockon are not reversed relative to the others? This would create a short and would explain what you are seeing.

Rod

Hi Rod, if the lock on to the grade was reversed then I would assume that as soon as the engine would pass over the block isolation point he would see a dead short through the engine rather then a power draw.

I am very interested in seeing what the results are from Stan's power audit.  I think it would be interesting to do on any layout.

I have my layout apart at present but as soon as it is up and running I will make a point to do the audit on a regular basses to keep a record of any wear patterns on my none DCS engines.

I do not think you will find any screw in LED bulbs which can take 22 volts input. Normally these are for 12 volts automotive applications. For command operation you could wire LEDs in series. described here

http://www.jcstudiosinc.com/BlogShowThread?id=407&categoryId=

Also the newer lighting strips are 3 in a series with resistors for 12 volts. You could wire 2 or 3 of these strips in series to run off 24 volts.

Dale H

Like mentioned earlier, I'm aware LEDs would be the best option, but because of my inexperience with wiring LEDs, I'd prefer to stay away from that option. I have currently resolved the issue by removing the light bulbs from my lionel great northern passenger cars ( they are older models from the 90s) whose lights can be easily removed. My other set of passengers cars is a MTH which I'd be comfortable switching out with LEDs if possible (assuming no wiring would be needed, but after reading the prior post, that appears not to be an option). I am also curious about adding the additional power to the track. I currently have two Lionel bricks that are not being used, and would be interested in wiring them to the track for additional power. Would this process be an easy one, or would I need to rewire the Z-4000 and TIU to accomodate the additional power source? Appreciate all the feedback and opinions.

Mike

Hi Dale, Mike can add as many transformers that he may need if he breaks them up via designated blocks. These blocks need to be isolated at the center rail. Of course all transformers need to be in phase so as to avoid a short when the train makes a transition between blocks.

With TMCC/Legacy this block isolation is not an issue because that signal travels on the outside rails. But, with DCS  Mike will have to run each power source  through it's own port on a TIU.

I like your phase clipping diode idea for car lighting alot, I think that little gem has to go to the top of my to-do list. Thanks!

A quick note on above post, some folks like to isolate the outer, or return rails as well as the center rail in order to provide true isolation, so the train transition short between blocks makes sense.

Obviously this would not be the case with TMCC/Legacy because the return path is common throughout the layout and any out of phase power source would cause an immediate short.

I'll be honest with you I think that with DCS the out of phase short would also occur at the return of the TIU and that could be devastating to the mother board, so please be careful when using multiple transformers.

I have four on my layout going through the TIU, but they all come off of the same power strip.

You can use a volt meter, or a test lamp to check between outputs of your transformers.  Red wire to red wire should show around zero volts, or no lamp glow. If you do get lamp glow or voltage from one transformer red out to another then they are out of phase, so reverse the AC pug at the power strip.

Mario

The problem is that when cars or engines with dual pickup rollers crosses the blocks,the transformers are put in parallel via a 22 gauge or less wire which connects the rollers. When this occurs there is a 20 amp potential is 2 blocks are bridged,a 30 amp potential if 3 blocks are bridged at once. This can be avoided with relays and a transition block but converting the cars is a lot easier IMO.

Dale H