So the gentlman who is refurbishing/rebuilding this 1945/46 Z transformer, says this blackend area is caused by heat. Further, the part at the botom is the circuit breaker(will replace) which he says was bent and would not have tripped, and that with a new cord, the coil current exceeds 1 amp at "idle" indicating a short exists. He will also try to reinsulate secondary at hot spot. Make sense? TW
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Not sure what you are asking - do you trust your repair man? Is it too costly to be economical?
No, no, I have to trust him, I just dont know any better. So kinda like a second opinion.
i know how that happened. AND, it was not the fault of the circuit breaker.
i know how that happened. AND, it was not the fault of the circuit breaker.
Are you thinking a short across two "power" terminals that was allowed to cook for a little bit?
That is what it looks like to me.
If so, that photo illustrates one of the reasons I put a Lionel #91 adjustable electromagnetic, manual reset circuit breaker on each "power" terminal, ("A" through "D").
IMHO the transformer is good for parts (aside from the coil). I don't see how it can be repaired without rewinding the secondary coil on the transformer. In my area a "Z" just doesn't cost enough that much.
This xfmr was hauled out last xmas after sitting for maybe 40 years or more. Came from my father in laws place. I used it for 5-10 minutes a dozen or so times but wasnt comfortable cause of the loud hum, original cord, and only one of the power dials worked. Thats why I sent it in for rebuild. It may not be worth using at this point when I get it back.
C W Burfle posted:Are you thinking a short across two "power" terminals that was allowed to cook for a little bit?
That is what it looks like to me.
Precisely.
Attachments
I don't understand the "short between 2 power terminals". I just tried this with a spare ZW not attached to anything. I powered up all 4 handles and touched a screwdriver across A-B, No sparks; A-B-C, Little spark; B-C-D, Little spark; C-D, No spark. U Terminal not hooked to anything. Is this from slightly different voltages across the handles? Education please
Education please
The handles have to be set to different voltage positions. Lets say you set "A" to 18 volts and "D" to 6 volts. Then put a meter across the "A" and "D" terminals. You should see about 12 volts.
You can do this with any two power terminals.
Judging by the picture at the top of this thread, there was a short across two terminals that did not have their voltage set that far apart.
Listen to Rob, the core is TOAST! I think trying to rescue this core is a fool's errand, and I sure wouldn't spend any money on it! I saw excellent rebuilt ZW transformers at the Allentown meet for $110-120 with a warranty, there's no reason to fool around with this one. It's extremely unlikely that I'd ever power this one on again, trusting the enameled wire not to short after you've cooked the enamel off is not wise!
Guns,
I agree with you 100%, some butcher abused this one badly, this one unless a person invests his own personal time into fully repairing, looks not to be cost effective to fix. Here in the Pittsburgh, Pa area, I can usually pick up a good old rebuilt ZW for around $100.00 or under, at one of the Train Shows, when the Vendors do not want to lug them home. Other wise purchase one from Jim Lawson right here on the OGR, he does great work on the one's he rebuilds and sells. I have both a ZW & KW from him, they have worked great for years.
PCRR/Dave
Looks like the work was already done. Lesson learned.
Hopefully he didn't spend more than it would have cost to buy a couple of better condition units... That invoice reads like a lot of "cosmetic niceties" were done as well to "restore" it.
-Dave
IF that secondary can be re-insulated(adjacent coils from each other) and the heat treatment hasn't affected the linear resistance of the winding, it would be operationally OK. I just don't know if that wire was tempered what the effect would be, but if it meets specs after repair, I would use it. It just does not seem to be cost effective, especially if the repair doesn't take.
IMO, this transformer should have never been "rebuilt", too bad because I think he was taken for a ride.
The proof will be in the pudding!
Yes, but it could turn sour a few months down the road!