zw transformer

[Dazedlion60]

I have a Lionel ZW transformer. I hooked it up to the new atlas 21st century track and to a Lionel Illinois central pass. set I have from the 1980's. It melted my circuit board in the "B" unit for the horn. The engines run fine, What I want to know is Why it melted the board and wires,and what do I have too do to stop this?????PLEASE HELP!!  Thank You!!!

[Anonymous]

The ZW's circuit breaker is rated at 15 amps.  Electronics will fry long before it opens.  The breaker is designed to prevent the transformer from cooking itself during a short, and not to protect whatever is connected to the transformer.

To prevent this type of failure in the future, buy a modern transformer or install 5-10 amp fast blow fuses inline with the track.

[ADCX Rob]

The horn board in the B unit probably came loose, shifted, and shorted to ground due to the age of the adhesive holding it down.

All early electronic-equipped Lionel locos should be checked for this to prevent damage.

[lionelsoni]

Actually, the tripping of a breaker or blowing of a fuse is your notice that the electronics are already toast.  They don't draw excess current unless they have already failed.  If there is an electrical cause of their failure, it is probably excess voltage.  A transformer can produce spikes of hundreds of volts when momentarily shorted.  A cheap and reliable cure for this is a transient voltage suppressor (TVS) installed across the transformer's output to limit the voltage to only a few dozen volts.

[Dazedlion60]

thanks for the info. Ill do that

[Dazedlion60]

ty Rob, looks like that is exactly what happened , the foam insulation is all deteriated.

[Dazedlion60]

ty, where could I get one of these (TVS) units? and what is the mimium volts that will work and still run the engine??

[Taranwanderer]

I can also attest to the fact that ZWs and modern electronics don't always play nice together, but I haven't had any issues since taking Bob N's advice about installing the TVSs across the outputs (although it took me a little while to wrap my brain around the idea of wiring anything across the "A" and "U" terminals when that's always meant "short!" to me.)  But good advice nonetheless.

[Dazedlion60]

thanks BOB, Ill get a (TVS) . Appreciate your info.   

                                                                                                                                      Ray

[bfskinner]

Dazedlion60

thanks BOB, Ill get a (TVS) . Appreciate your info.   

                                                                                                                                      Ray

Buy a bag of them. In their "raw" state (adequate for your needs) they only cost about 50 cents apiece.

.

[lionelsoni]

I agree.  You can use one on each of the four outputs of your ZW.  I recommend the 1.5KE36CA for use with a ZW.  That's a bidirectional 1500 watt 36-volt axial-lead TVS, made by Vishay and many others.  Be sure that your part number ends with "CA" and not just "A", which would be a unidirectional device which cannot be used with alternating voltage.  The bidirectional ones have no polarity consideration and can be installed either way directly across the transformer output terminals or anywhere between there and the track, or even inside the locomotive if you like.

[gunrunnerjohn]

I think the response that says the damage is done is the correct one.  I don't disagree with additional protection, but by the time most circuit breakers trip, whatever is cooking is already well done.