Can my ZW Transformer be repaired?

[Anonymous]

The other night I was putting in some isolating blocks on my existing layout.  Something happened, I'm not sure what, to short out my 1953 vintage ZW transformer.  The circuit breaker, which on this model shuts down the transfomer and causes is a beep, did not seem to work.  The result is that the Track A control no longer puts out any power.  The track B still works.

My question is, can a ZW be repaired and, if so it it worth repairing a transformer that is that old?

[dwiemer]

I am sure it is.  It sounds as if the breaker worked and got stuck.  Bob N. and some others would be better than I to answer, but I would go ahead and repair it.  When you do get it going, be sure to purchase some quick blow circuit breakers or fuses that will trip before any more problems.  If you have the newer engines with the boards in them, you could fry a board.

Dennis

[Anonymous]

Was there any smoke when the transformer shorted?  The good news is that the coils are fine since you have voltage at BU.  Most likely, the roller on the AU contact arm burnt, or the wire connecting the contact tab for the AU arm to the A binding post burnt or came unsoldered.  The circuit breaker will definitely need to be replaced.. The ZW is a great transformer, and is woth every penny to have fixed.  If you are not comfortable servicing a transformer, take it to someone that fixes postwar Lionel.  Hope this helps.

[lionelsoni]

It's possible that what happened is the sort of fault that we've been quarreling about on this topic:  http://www.trains.com/trccs/forums/900495/ShowPost.aspx  If you shorted two of the outputs together, the circuit breaker would not be expected to operate.  So I would not assume that there is necessarily anything wrong with it.

I doubt that the breaker is stuck open, since that would not leave any of the outputs working properly.  I suspect that something is burned out in the A circuitry only, perhaps a wire or one of the whistle-switch contacts.  You can disconnect the whistle switch and bypass it to see whether that restores the basic output.

Here is a schematic diagram:  http://pictures.olsenstoy.com/cd/transfmr/psvw1.pdf

[Jumijo]

Don't send it to Roseyville for repair. 200 v output! Yikes!!!

Jim

[traindaddy1]

MY TWO CENTS:  I just had mine (circa '54 - 115v, 60 cy, 275 w) repaired...."B" terminal died!  The problem was corrected and along with a new cord, rollers, rollers rivs, bind posts w/nuts, cover screws, an overhaul..and some other stuff that I really don't understand---Took five days, works great! I'd do it again.  FOR ME, well worth the $48.

[ChiefEagles]

Don't send it to Roseyville for repair. 200 v output! Yikes!!! Jim

Yankees send defective ZW's.  Us REBS fix them.

If you fix it yourself, install the automotive type circuit breaker.  Get the one with blade terminals.  Get a fuse holder for that type and solder it in.  Plug in circuit breaker.  Do as Bob suggests, install 4 more.  One between the all the out puts.  [Is this right, Bob?]  The one in the ZW now is on the common [which is a bar and all the commons feed from it]. 

Question for Bob:  Why is the breaker on the common? [ground].  Electrical rule: never put switch or breaker on the ground side.    

[lionelsoni]

It's obvious to me that Lionel was trying to save money.  Putting the circuit breaker there was the only way to get away with using a single breaker.

Actually, there is a lot to be said for putting switches and contacts on the ground side of a circuit.  It is the usual practice in telephone relay circuits, where considerable logic is implemented by elaborate relay-contact networks.  The advantage is that accidentally grounding the extensive wiring practically anywhere is safe, in that it simply operates the wrong relay coils, but doesn't cause a fire or interruption of power to other parts of the equipment in the telephone exchange.  When we wire turnouts or accessories to a control rail, we are doing much the same thing--switching ground.  That is why it is reasonable to use much lighter wire for those tasks:  A heavy wire may supply track voltage to one side of the switch coils, but light wires can be used to throw the turnout by completing the circuit to ground since the turnout coils limit the current that could be drawn if the wires between the turnout and the controller were accidentally grounded.

I should add that it Frank is right about switching the hot side when the voltage is high enough to be an electrocution hazard, which is of course the case for our 120-volt power lines.  The telephone folks use -48 volts DC, which is borderline; and our low train voltages are hardly any danger at all.

The original ZW breaker is rated at 15 amperes and that is what you should replace the main breaker with; but I suggest considering using perhaps 10-ampere breakers for the individual outputs, which should be plenty for any one train.

[Anonymous]

Thanks for the response.  Can you recommend somewhere to purchase "quick blow" circuit breakers and how to install them.  I have a fairly limited knowledge of wiring, but I just ordered some books.  I don't want this to happen again, because I know I will have more shorts in my future.

[lionelsoni]

You don't really need anything faster than the automatic-resetting automotive breakers to protect the transformer.  The important thing is to add them to the individual outputs as well as to the common.  Then the kind of fault that you probably had, shorting between outputs, will be taken care of.  The breakers just go in series with each of the four output terminals, A, B, C, and D.  So you can put them either inside or outside the transformer case.