SHORT VERSION: how does one go about assessing and fixing a transformer (old Lionel ZX 250 Watt) that appears to be putting out low voltage?
DETAILED VERSION: Hello all. (I apologize if this question is answered somewhere on the forum – I did attempt to search, but all of the search terms I tried turned up exactly the same, irrelevant, posts.)
I (my son, really) just inherited my grandfather’s Lionel O-guage train set, most of it from the late 1940s. It uses the Lionel ZX transformer, 250Watts, I believe from 1948 or thereabouts. We had it running fine for a few days. The train would slow down a bit when far away from the transformer (as expected), but run just fine.
Then one morning it stopped working. The immediate sympton was that the train lights and horn would work, but it would not go. Tried other engines – same result.
After many fruitless attempts to get it going, I tested the transformer with a volt meter (touching the leads of the meter to the A and U posts on the transformer) and discovered that it is putting out only about 1 volt when at ‘full throttle’. The same is true of all 4 pairs of posts on the transformer
Is this the sort of thing that ‘just happens’ to these things, or are we likely to have done something to mess it up? (I read all of the instruction manuals, and tried to follow them religiously, but maybe I missed something?) Can it be fixed? By me?
Thanks very much for any help.
Michael,
Interesting. I assume you are talking about a ZW transformer?
The same secondary winding feeds all 4 circuits, with a carbon roller for each handle that contacts the secondary to provide the desired voltage as tapped from the winding.
What is interesting is that you say the loco lights and horn work, but you are anly getting 1 volt from the transformer. Horns and lights do not usually work at 1 volt.
Did you make your measurement with your voltmeter using an AC or DC setting?
You need to measure the AC output of the transformer.
Lionelsoni will likely have some usueful insights on this.
A schematic diagram of the ZW is available here.
http://pictures.olsenstoy.com/searchcd31.htm?itm=671
As Roy suggested, we need for you to confirm that you were using an AC voltmeter. We also need to know whether you measured the voltage under load or open-circuit. It’s possible that the circuit breaker is stuck open and that you are seeing the small current that can get through the indicator lamp. It would also be useful to know whether you can measure any voltage between the outputs, like A to B, with one handle up all the way and the other up just a little. This circuit does not involve the circuit breaker and therefore may give us a clue.
Michael,
It would be useful to know what trains you are running with the transformer. Tell us the number on the side of the engine and confirm you are just running older postwar Lionel trains (or what train you think it is).
BTW - Welcome to the CTT Forum! [#welcome]
Have you tried cleaning the windings just under the cover, on a 275 watt ZW the top is held on with 4 screws, try cleaning the roller wheels and surrounding with a clean rag. Power cord must be removed before working on the transformer. I have not had the problem you describe happen but it sounds like a maitanance issue rather than a malfunction. Do not oil the coils or rollers inside as this reduces electric flow.
Lee F.
Yes, ZW – sorry for the typo.
OK, my mistake (I’m new to this, but interested to learn) – I remeasured the voltage on AC and it looks OK. Putting the leads straight onto the A and U posts, with the transformer disconnected from the track, I get a smooth range from 0V to about 17V when I push the handle through its range of motion. Pushing the whistle/horn lever brings it up to 20V as long as the whistle/horn lever is pushed forward. I get these same numbers on all four pairs of posts (of course the whistle levers work on only two of them).
With one lead on A and another on B, and the A handle all the way forward, then pushing the B handle forward, I see a smoth increase to about 9V or so, then quickly decreasing back to 0V as I continue the push the B handle forward. Same story for A-C and A-D.
As for the engines: The one that I had done the most testing with is a Lionel Sante Fe BLT 8-57 #215. I believe this one is fairly old, as I remember playing with it (or one just like it) as a child. Another one is, I believe, much more recent. It is a Lionel Pennsylvania 8446. Both of these engines ran just fine one evening, then next morning … nothing. Both of them behave exactly the same way – lights and horn, but no motion. The same happens if I just touch the wires directly to the train, (as the manual suggests).
I’ll start studying that schematic diagram. Any other hints or advice you can give me are very much appreciated.
Now try measuring the voltage with the locomotive on the track. Cycle the e-unit (if you can) and measure the voltages in neutral, other than neutral, with whistle blowing, etc. I am guessing that, in neutral, you get substantial but not full voltage on the track, enough to light the lights, but, out of neutral, the voltage drops to the volt or so that you mentioned before. If this is true, it indicates that the circuit breaker is open. You can verify this by removing the circuit-breaker lamp, in which case you may not be able to get any voltage out of the transformer, A to U. But A to B should still give the same voltage as before.
Michael,
Two things.
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Are you sure you have not inadvertantly turned the e-units off (lever on top of the loco)? This can cause the loco to be stuck in neutral and would explain why the lights and horn work.
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I am also wondering if your mechanical e-units in the locos are stuck. Since these locos are fairly old, the mechanical e-unit is how the loco reverses the windings in the motors to reverse direction. A simple approach is a shot of TV tuner (or contact spray - still sold at Radio Shack) into the e-unit to clean any dirt out of it. Worst case is disassembly which usually requires an experienced technician as thes guys are tricky to reassemble.
The typical mechanical e-unit uses a vertical solenoid using a pawl to rotate a small drum that has electrical contacts that reverse the motor windings to reverse direction. The solenoid requires gravity to return to its resting position after rotating the drum. If this is not all very clean (do not use any grease on it!) it will not work properly.
Nice job on the testing you did.
Thanks again to you and lionelsoni for the helpful advice. I’m at work, now, but I’ll try the tests you mention when I get home. (I did play with the e-unit on the Santa Fe, thinking that it might be stuck in neutral, but no luck. Of course, if it is malfunctiniong, that’s a different story. I’ll try cleaning it as you suggest. I’m no train expert (obviously), but I have what I suspect might be many of the relevent tools, etc., as I am a long-time builder and flyer of RC airplanes, gas and electric, so I might take the plunge and attempt to dissassmble it myself. I guess the worst-case scenario is that I end up carrying a box of parts into my local train shop and humbly begging for help…)
Eureka! This turns out to have been quite an unfortunately bizarre situation. After carrying out all of the tests that you all recommended, cleaning the contacts, checking the circuit breaker, etc., etc., and one by one ruling out possible problems, it became clear that something must be wrong inside the engine. I had resisted this conclusion because it seemed so incredibly unlikely that two engines would simultaneously develop the same problem – that’s why I blamed the transformer – but believe it or not that’s exactly what happened. I opened up the Santa Fe and found that a wire from the motor to the reversing unit had simply come off. I soldered it back, and presto! The engine worked. I then looked inside the Penn. engine, and a wire had come loose in there too – not the exact same wire, but the same effect (disabling the motor). A little solder, and all is well. If I didn’t know that nobody had touched the engines over night, I would have suspected some sort of practical joke, because it seems so unlikely, but there you have it. (Didn’t Sherlock Holmes say that when you’ve ruled out everything else, then whatever is left, no matter how improbable, is the culprit? I guess he was right.)
Anyway, I’m very apreciative of your help, which did finally lead me, by process of elimination, to the improbable culprit. I hope to continue to learn a lot from the expertise on this site.
Glad to hear that you solved your problem! I was going to suggest using another transformer to see if that was the problem.
Any way when trains sit for a while you need to do some maintanance work such as cleaning the brushes and armature.
Lee F.