O27 Shorting out Please Help!!!

Model Railroader General Discussion (Model Railroader)
1

Hi,

I have a friend that has some O27 from the 70’s and he is having some problems with it. He told me that it would spark and then the train would stop. He asked me if I knew the problem, so i’m asking you guys since I know nothing about O27.

Did I post this in the wrong forum?

Thanks for any help,
dekruif

2

You’d probably have better luck posting the question under the Classic Toy Trains heading.

But like any short, the first question I’d ask is where did the spark come from? Electrical shorts are the same thing whether it’s on AC or DC. 027 uses a center rail that’s insulated from the others at the tie. The circuit is through the outside rails (both are the same pole on this type), up through the motor, then back to the track through the center rail. The electrical connector should clip on between the outside rail and the center rail, plus it should not be clipped on so it goes under all 3 rails, this in itself could cause a short.

Also, if your friend isn’t that familiar with 027, you may want to start by checking this connection. Especially if he’s used to 2 rail pickup like used on HO, he may have this connected wrong.

3

If the rails and/or wheels are dirty, the engine will typically lose contact momentarily. Excessive sparking is an indication of dirty wheels and/or track. When electrical contact is interrupted, the E-unit in the locomotive sequences to the next position. E-units on O27 engines go through a foward-neutral-reverse-neutral-forward sequence upon power interruptions - whether intentional or not. Two ways to check if this is the problem:

  • clean the track and wheels and see if the problem is still there.

  • move the E-unit lockout lever to the locked position while engine is trying to move forward. This locks E-unit in forward only (engine cannot reverse or go to neutral).

These tests should be done 1st to troubleshoot.

my thoughts, your choices
Fred W

4

I’d take a close look at the track itself. As I recall, old O27 used metal ties and rails, so there was a fiber insulator between the center rail and the tie. If that insulator has worn out, you might see a problem when the engine or a heavy car passes over it.