Problem with KW Transformer

The circuit breaker is a likely cause, if it can produce voltage without load then it could be the breaker is tripping too early. Does the same thing happen on the fixed voltage output and on both variable outputs? If so, I would guess it was the circuit breaker. 

Yes the response is identical on both variables and both fixed taps. Is there a way to adjust the breaker to cause it to trip for higher current levels. If needs replaced, what would be the best part to use. and where could i get it from. I thought I remembered folks talking about replacement breakers that were better than the Lionel 50s design for these units. 

The rivet that secures the CB contact stack together typically fails. About 20% of the KWs that I serviced have this problem.  It is best to replace it with a modern CB available from the Train Tender (www.ttender.com)

A partial parts view for the KW and circuit breaker is here.

The replacement part is available from Olsen's here.

Larry

LIRR Steamer posted:

Yes the response is identical on both variables and both fixed taps. Is there a way to adjust the breaker to cause it to trip for higher current levels. If needs replaced, what would be the best part to use. and where could i get it from. I thought I remembered folks talking about replacement breakers that were better than the Lionel 50s design for these units. 

    There might be an adjustment. I've seen three different breakers on KWs.

If we're thinking of the same group of threads, the modern ones were better in general, and reacted faster, was the consensus (IMO).

  If you the extremely impatient type, an automotive, self resetting 12a breaker could be retro fitted.  

  The ones from "supporting a hobby shop" are cheaper in price, should mount right in, and likely do the job just fine and dandy. There are usually spec sheets on those products if you take the time to research the Mfg.

LIRR-   It sounds like a breaker but you should check inside for 'debris', as well as the rollers/sliders, and windings. IMO, you should look in any transformer before you buy it, or at least before you use it. Medium-large Lionel transformers often seen only 4 screws and maybe the handles removed, to lift the cover, and look. (just unplug it if you "worry")   While you're at it, KWs hold a real interest for me; a KWs throttles swing clockwise, so if your's (or anyone's) happen to be opposing (even just the voltage numbers) please contact me. {E.g.-both swing Counter Clockwise for off is normal, or both "to you" for off }

 INSIDE- Look for amp limiting wear like scoring, sawing from broken rollers, or heavy wear (flat/divit) on the winding, and/or heat discoloration on the roller/slide arms, etc.

To do a roller with pliers? Better buy extra rollers, and about 3 pins per roller. Wheels can be brittle, and no warping the axle pin, or it's wrong, and won't turn right under the arms pressure. Tricky at first, to find just the right pressure needed, but not too hard.

The breaker is simply stuck open.

I would recommend against trying to adjust the circuit breaker inside a transformer. How are you going to calibrate it? If it isn't working properly, replace it.

I would try to get an original or equivalent replacement part for the KW transformer. There is not that much room inside to replace parts that are over-sized in any way, at least that is what my local hobby shop guy told me when I asked about updating my KW to modern type of rectifier disks for the whistle control. Also the KW's handles have to be pulled straight up to come off(there might be a set screw in the handle that has to be loosened first), and then you can get to the screws.

I would go with Olsen's or the train tender for parts.

Lee Fritz

Thanks folks for all your insight , help and recommendations. I will order the new circuit breaker assembly and install so I can get this KW working. 

Appreciate all the help and suggestions and tips