[eatrains]

I'm running some of LGB's Amtrak Amfleet cars off of a MRC Command 2000 and a Power Station 8. If one or more of the cars' lights are switched on when I start sending DCC signals and power to the track, everything is shorted out and nothing will run. I can hear that buzzing coming from each car. If I then switch off the lights or tilt the cars so one side is off the track, everything comes back on and works fine, for a while. If the lights are left switched on, the trains will, after a while, stop and everything will be shorted out. If I repeat the switch-off/tilt fix, everything comes back on. I don't even need to reset the Command 2000. Everything's fine if the lights are left switched off. If the Command 2000 is connected directly to the tracks, without the Power Station 8, everything's fine, including the lights. Does anyone know what's going on?

 

[rwbrashear]

Hello EA-

If it isn't one particular car that is causing the problem, it could be the capacitors in the lighting circuit. When they charge, they are pulling more current for a short period of time. The Power Station 8 sees the capacitors as a short and trips the overload. I read the Power Station 8 manual and their does not appear to be a method of adjusting the overload time. If the trip time before an overload occurs could be relaxed, the system might work.

You can try adding a PowerShield from Tony's Train Exchange. It is designed for this type of problem.
http://www.dccspecialties.com/products/pdf/psx_hints.pdf

http://www.tonystrainexchange.com/index.html

Best regards,
Bob

 

[altterrain]

I had the club meeting at my place a few months ago. A member brought her Forney and new out of the box LGB passenger car to run with it. There was buzzing and a semi short in the system. At first we thought it was the Forney but discovered it was the passenger car. There was a cross wire in the lighting circuit. Switched wiring around and all was fine. I'd check the cars one at a time to see if anyone in particular is the culprit.

-Brian

 

[eatrains]

It isn't any car in particular. Any and all of them will cause the problem. Rwbrashear, do you know of a way to confirm that the problem has to do with the capacitors?

 

[rwbrashear]

Hello EA-

Unless you have a scope, it's hard to determine whether the capacitors are actually the problem. (I am also assuming the Amtrak coaches have a lighting board similar to other LGB lighted passenger coaches.) Can you access the circuit board and determine the capacitor value?

This may not work, but you can try adding an #1156 automotive lightbulb in series with one of the track feeders. The bulb should limit track bus shorts to approximately 3A.

In H0 scale, boosters often have problems at start-up when there are multiple sound locos in the same power district. Since all of the capacitors are charging in tandem, the resulting current demand trips the booster's overload circuitry.

Video explanation:
http://mymemoirs.net/model-trains/images/previews/TSL3/shortMgmt1_bbhi.swf

Another explanation:
http://www.wiringfordcc.com/track.htm

Please use caution, as even though the bulb limits current during a track bus short, a real short left unattended can still cause damage to your locos, rolling stock, track, etc.

Also remember, the #1156 is a 12V bulb. It will work for the test.

Good luck.

Best regards,
Bob