How To Fix Shorts When Powering Up Locos

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March 30, 2015

Jim asks readers:

“I have a DC HO layout after redoing part of the layout a short has developed which only allows me to power up to about 1/3. If I go beyond this I get a short. If I back down the power the train will slowly start to run. I have already checked over the layout for shorts. My question – could a turn out be causing the problem?”

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3 Responses to How To Fix Shorts When Powering Up Locos

Glen Wasson says:

April 4, 2015 at 12:24 am

Sorry, but you broke the No 1 rule of model railroad electronics, no separate blocks.

Most turnouts will direct power to the selected root from the single feed end. You say you get power to only 1/3. Is this 1/3 of the layout, or only 1/3 power to a particular track.

Poor, or corroded connections between individual track pieces will reduce the voltage be end the feed points where you attach the power leads from the power pack.

See if this is any use. I just got called to dinner. Armchair aka Glen itzaduck.com

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Newman Atkinson says:

April 8, 2015 at 2:42 am

Are you running buss wire around under your rails with drop wires to routinely connect to your tracks? If you are running a layout that is feeding through the rails only, then power is lost the farther away from your transformer you get.

Does it short without the engine on it then it is in your track work. If you have on/off switches to control sections of track then start shutting them off and see which one has the short.
from Newman

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Frank Bushnell says:

April 15, 2015 at 3:57 am

Hi Jim, it sounds like you are describing a fault on your controller.
If there is a short on the tracks, it will prevent locos running at any setting of the controller.
Connect the controller to a single isolated piece of track with a loco on it and see what happens as you turn the power up. (Hold the loco to let the wheels slip.)

But if the controller is OK:
Connect a 12V lamp in series with one controller output wire to the track. Power on.
With no locos on the track, the current should be zero, so the lamp should not light.
If changing the turnout causes a current to flow (the lamp lights), then you have a short in that area.

Please let us know what happens !

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