Weird Loco Electrical Short Issue

[rrinker]

 Perhaps that all is exceeding 5 amps, but you did say you tried in various combinations, not necessarily with all those locos on the track at the same time. I still think that if all those locos are in peroper workign condition and don;t have issues with their motors or anything, that is less than 5 amps total, even witht he lighted cars - though the incandescnet lit cars are going to be the single biggest power hogs, not to mention the inductance of the incandescent lights distorting the DCC signals. Simple enough to try, take all the lighted passenger cars off and see if it work then. If not, then it's still a loco problem, not a power problem. If it all works fine with all the locos but not the lighted cars, it's probably a power problem.

 Also, does this happen only when all the locos are running, or even when all the others but the BLIs are parked? A parked sound loco doesn;t draw that much power, the motor current is still greater than the sound circuitry power draw, so if they are all just sitting there and you try to move JUST the 4 unit set including the 'new' loco, if that dies, it's not likely it's a power problem. I have had as many as 8 locos, most with sound, actually moving all at the same time with the Zephyr which only has 2.5 amps. No lighted passenger cars though.

 The fact that the sound does not work in the Blueline could point to other problems with the loco as well.

                               --Randy

 

[Arto]

Greg, you are correct. Actually, I came to the same conclusion about an hour after posting. I guess you might say this (additional loco) was the straw that broke the camel’s back.

 

For those interested in how this transpired:

Digitrax PS2012 power supply

Digitrax DCS100 5amp command station/booster

 

Three trains on tracks

BLI Alco RSD-15 w/lighted caboose (LED)

4 BLI Blueline C30-7 w/lighted caboose (LED) (one loco is the “new” used loco)

2 Athearn Genesis w/ 11 lighted passenger cars (2 LED, 9 incandescent)

All locos have sound (except for the “new” one in which the sound is not working for some reason), all are powered.

 

DCC is still relatively new for me. My previous DC setup had two 5 amp bricks, one for each mainline. From what everyone was telling me, “5 amps should be more than enough, we run our whole club layout with that”. From my personal experience with the kind of trains I run on my layout I was kind of skeptical that one 5 amp source would be enough. I’m pulling about 3.25/3.5 amps with everything running so it seems quite reasonable that I’m pulling more than 5 amps surge when first turning on track power. And that of course would be enough to trip the circuit breaker. The Athearn Genesis were recently added to the DCC roster. Prior to that I was using all BLI. So, yes, the BLI appear to be pulling less current since I wasn't experiencing the same problem (yet). Regardless, I guess I’ll just be using two boosters sooner than I originally planned. There’s another new section being added to the layout and it too will have it’s own booster/power district and run independent of the main layout.

[mfm37]

What DCC booster are you using? What is its current limit? Do you have any way of measuring the current draw of each engine? (RRampmeter?)

This one could be drawing more current. enough to make the system go overcurrent when it is combined with enough other engines.

[MisterBeasley]

Does "on the track" mean on the track some distance from each other, or are the engines coupled together?

I'm thinking that the engines might have "hot" frames and there's a short through the couplers.

[gregc]

Arto

Just purchased a used Broadway Limited C30-7 Blueline.

it runs fine as well as with another BLI Paragon unit.

When I put my Athearn Genesis (Tsunami decoders) on the track (DCC) I get a short when I turn the track power on.

just to be clear, you're saying just having both of these locos on the track causes a short without actualling running them (making them move).

when you say short, you mean exceding the max current of you're supply.

since sound units draw current even without running the loco, could it be that your new Blueline with the bad sound unit is drawing more current than it should.   When you put another loco on the track, their combined current draw excedes the max current.

Could it be that the Genesis also draws a lot of current (normal) but less than the BLI and excedes the max when both the Genesis and Blueline are on the tracks together.

can you check the current draw of your new Blueline or disconnect the sound unit.

[Arto]

Just purchased a used Broadway Limited C30-7 Blueline. The seller informed me that the sound does not work but otherwise runs fine – which it does ----- except……………………………

 

By itself it runs fine on DC or DCC, with the DCC plug, or with a new Digitrax DN146IP decoder. When run with three other BLI locos of the same kind, with the same decoders, it runs fine as well as with another BLI Paragon unit.

 

When I put my Athearn Genesis (Tsunami decoders) on the track (DCC) I get a short when I turn the track power on. These two locos run fine with the other four BLI units. I get a short only when one or the other of these two Genesis are on the track with the new (used) BLI Blueline loco.

 

Any clue as to what’s causing this?

 

EDIT:

I also tried using two other Atheran Genesis DCC ready loco (no decoder), and an older Kato (DC) and got the same short when this "new" (used) loco is on the track, with either a DCC plug or decoder installed. Using another BLI Paragon 2 everything is ok. So it looks like using all BLI is OK. Using any other brand loco, DC, DC/DCC-ready, or DCC I get a short. With all BLI, Blueline or Paragon everything is OK.