ZW (Terminals A & U) producing power with handle in off position

[Uncle Charlie]

Good evening.  Hopefully my explanation will make sense on this rather odd occurance on my postwar ZW 275 Transformer.  When I connect the wires from my illuminated lock-on to the A & U terminals, even though the right hand throttle is all the back, power is escaping lighting up the lock-on as well as providing jst enough power to the locomotive to make the E-unit buzz.  Nothing else is hooked-up to the ZW at the momment.  This only happens with the right throttle, no issues with the left.  Greatly appreciate any recommendations to resolve.

[Leverettrailfan]

Maybe an obvious question, maybe not, but... do you know when it was last serviced? I might suggest taking the top cover off with the transformer unplugged, just to see if you can observe any problems, like a broken carbon roller or a wire with a broken solder joint, or anything else that looks "not quite right" to your eyes. Don't mess with it if you don't think you know what you're doing, but it's good to check in case you spot something. 

I can't possibly be the authority on everything that can go wrong with a postwar Lionel transformer, but one thing I can say, is that the behavior you describe sounds to me like somehow the handle isn't moving the roller arm for the throttle all the way to the "off" position. But that isn't the only possible explanation. 

Hope this helps a little.
-Ellie

[7j43k]

The ZW transformer has a wiper for each of its four "dials".  They roll or rub along the side of the enclosed transformer, which gives the varying voltages.  When "off", the wiper should not be on any of the metal windings.  It sounds like your "A" wiper is.

If yours is like mine, and it probably is, unplug the transformer.  Take out the four screws that are in the corners of the top.  Lift gently--ya don't want to damage anything.  Mine came/comes off nicely.

When the top is removed, you can move the dials and see the wipers move.  A visual examination will probably reveal the problem.

 

Ed

[Uncle Charlie]

Thanks all.  Problem resolved.  I removed the cover and sure enough the roller was still making contact with the windings,  I understand this sometimes happens during shipment if the package takes a bump or two.  I contacted the fellow who sold it to me and he walked me throught the process of correcting it.  I placed the A throttle in the half-way position, held the roller in place with my left hand while slightly moving the A throttle forward. After bringing back the throttle to start posiiton, the roller was clear and resting on the plastic.