When I made earlier posts about shorting A, B, C, and D together, I was assuming that only the center rail between blocks had an insulating pin. If all 3 rails have insulating pins (which IMHO makes things much more complicated than necessary) then you could connect U to the center rail. Then you don't need to insulate the center rail, only the two outside rails.
With this arrangement, you will have a lot of fun making non-derailing switches work, as the voltage supplied to the switch will not remain constant but will depend on the voltage on the track.
In summary, connect the outside rails to U on a multi output transformer (V, Z, KW, ZW), and everything should work fine.
Bruce Baker
Please stop saying "center rail" and "common" in the same sentence, even in the subjunctive mood as indicated by the "If" and "were." From this point forward, no one will ever again consider such a hookup. No, not even as an intellectual exercise among MIT graduates!
If the center rail were common, there would be no voltage difference on it from block to block. Any pickup roller touching the center rail on one side of the block boundary would still be touching the same electrical node on the other side, whether or not there were a track pin in the center rail at the boundary.
Whether the wheels on the outside rails would intermittently or continuously connect the two non-common transformer outputs depends on the type of cars. With metal frames, the connection would be pretty much continuous throughout the train. With all-plastic bodies, the connection might be through the couplers of each pair of trucks. With plastic couplers and truck frames, the connection would be very intermittent, as individual wheelsets rolled over the gaps. But this behavior would be the same for non-illuminated as for illuminated cars.
Bob Nelson
Right, but isn't it true that what is significant to this discussion about illuminated passenger cars is the fact that they tend to have pickup rollers running on that center rail, and as such would be repeatedly making and breaking the circuit as those rollers moved along the "common" center rail, from a block at one voltage to another block and a different one, in effect straddling the blocks over and over again, far more frequently than one would by keeping the outside rails common and being vexed by the relatively rare occurrence of the analagous phenonemon with the two close together pickup rollers on the locomotive?
With apologies to John Keats: "Power to the center rail, common to the outside ones; that is all ye know on earth and all ye need to know."
.
Actually the "on-again, off-again" faults produced by passenger cars correspond to the outside-rail common, with the faults occurring at the gap in the center rail.
Thanks Bob. That was exactly the point I was going to make in the section in an earlier post that I drafted but then deleted. I specifically used a string of illuminated passenger cars as an example of the on-again, off-again series of faults that could occur if the one used the center-rail as common. It was also the reason that I referred to "center-rail common" scheme as the "silly" method.
We have run into this "common" problem before. I have repeatedly tried to point out that in the "old days" of pre- and post-war trains, Lionel often gave the operator the choice of what terminals to use for "common"; but from a practical point of view, those days are gone forever -- except for the recent dust-up over the curious factory cross-wiring of the early Lionel CW-80 transformer/controllers.
I for one am fully persuaded that the operator needs to identify the common terminal(s) regardless of how the transformer may be marked; and then connect them to the outside rails, and be consistent throughout the layout.
I also strongly recommend that anyone who is at all serious about toy trains obtain an inexpensive multimeter or, at minimum a continuity checker. This thread could have been settled by the first response if the original poster had just determined which posts were common.
PS. On the advice of my dentist, I not only eschew blocks, I also eschew gum.
Now that we may have settled the question of which terminals are common, with your indulgence I would like to explore the question of which rails to connect those common terminals to, since it goes to the heart of why I am always harping on how not to run from block to block.
I think that bf is right about the possibility of connecting the common to the center rail. That should work just as well as the usual connection to the outside rails if the operator is conscientious about supplying both blocks with exactly the same voltage waveform. A will be connected to B (or whatever) in any case; and, if the voltages are not matched, a fault current will flow. The only difference between the two cases is that the problematic connection will last much longer than the distance between two pickup rollers if U is on the center rail.
With the fault on the outside rails, there are some additional hazards. It seems much more likely that a significant voltage difference will drag the transformer's voltage down to the point that the train will stall and just sit there while wiring and transformer go up in smoke. Another likely problem is burning out the knuckle springs in couplers, which is surprisingly easy to do between two trucks at different potentials.
With the fault on the center rail, electronic damage seems more likely. The fault will come and go as each roller or roller pair passes over the joint, creating voltage spikes. A lighted passenger train should produce lots of them.
Now even if we try to use good block hygiene, keeping blocks powered by the same output as the train moves around the layout, there is always the possibility (probability?) of making a mistake. This to my mind argues for common outside rails, with TVSs to help with the occasional slip-up where electronic locomotives are involved. Bf of course can easily do it either way, since he eschews blocks.
lionel2Then it would hook up the same way as my other Z transformers.
You got it.
These guys have better eyes than me. I can't make out the "U" strip in the pic, but I know it's there.
Rob
servoguy bf The U terminals are all tied together. Everything that you tie to a U terminal is tied to everything else tied to the U terminals. So if you tie the center rails of 4 blocks to the U terminals, they are all tied together, and you don't have block control. If you had separate loops that were not electrically connected in any way, you could connect the rails either way, and it would work. If you tried to connect the center rails to the U terminals, you would create another problem. The outer rails would all be connected to the A B C D terminals, and this would short the A B C D terminals together which, under the right conditions, will create smoke. As Bob Nelson has pointed out several times, "Thou shalt not connect A B C and/or D together." Bruce Baker Bruce Baker
bf
The U terminals are all tied together. Everything that you tie to a U terminal is tied to everything else tied to the U terminals. So if you tie the center rails of 4 blocks to the U terminals, they are all tied together, and you don't have block control. If you had separate loops that were not electrically connected in any way, you could connect the rails either way, and it would work. If you tried to connect the center rails to the U terminals, you would create another problem. The outer rails would all be connected to the A B C D terminals, and this would short the A B C D terminals together which, under the right conditions, will create smoke. As Bob Nelson has pointed out several times, "Thou shalt not connect A B C and/or D together."
I still cannot agree. If the blocks are properly insulated/isolated from each other, I can't see that it matters whether the power from a given block is fed from the center rail or the outer rail. But that is not the point. Personally, I don't use blocks and never will.
[At this point I wrote several paragraphs explaining how I think such a silly method would work, but decided to delete them because 1. it's too difficult to explain without diagrams; and 2. it's not important to this thread anyway.]
Back to the original point: The member must determine which four of the eight posts on his Type Z are common, and connect them to the outside rails. Period!
On that we should be able to agree.
I suspect that when Lionel marked the particular Type Z in question, without specifically labeling the U posts as such, it wasn't thinking about blocks or bells . Rather, their concerns were about rolling down the track and blowing the whistle/horn, If that was the case, then it didn't matter which wire was to be connected to center rail and which was to be connected to the outside rails -- which was all that I intended to imply. I only wish I had a copy of the instructions that came with the Type Z in question.
* Incidentally, I do know enough not to connect post A to post B, and have known it for over 65 years. Thanks for the reminder, though.
lionelsoni I agree with Bruce, that the top row is likely to be the common.
I agree with Bruce, that the top row is likely to be the common.
Thanks for your support, Bob.
One small point. In the Complete Service Manual for Lionel Trains, by K-line, Reprinted 1982 by MDK, Inc., page 672, there is a representation of the faceplate of a Type Z of uncertain vintage. It clearly shows two lamps, with plastic caps. (Part numbers: red R-68 and green R-69,) Clearly there were other versions.
So the one thing that is certain from this thread (as I believe I suggested in my initial post above) is that there have been variations aplenty with this device. Possibly some of these were due to wartime shortages or depression-era supply issues. There is no doubt Lionel shipped Z's with one lamp as well as those with two; and some with colored bulbs as well as others with clear bulbs and colored caps.
So, The bottom line is that the top row is common ground or U posts. And the bottom row of terminals are the power or middle rail posts, correct?? Then it would hook up the same way as my other Z transformers. Thanks for all the help.
I have never seen any of these variations. However, it is interesting that the 4 dials on all the ones I have are in fact numbered. I have seen many with naked colored lamps, enough that I have suspected that this was a normal feature. The very short 4-page 1946 catalog shows a type Z with a rather different faceplate and two lights, but at the bottom of the panel, not at the top. They don't appear to have caps over them.
The guy selling the Z has some odd ideas. The hole he cut in the case seems out of character with his emphasis on doing everything just right, like the Lionel factory. The idea that he paid $239 for his digital meter to measure the voltage-out to two decimal places while ignoring the voltage-in and that this somehow enhances the value of the transformer is ridiculous. And, if all you need to run your train is 15 volts, then those extra 10 volts are completely wasted. In any case, they have nothing to do with the power rating of the transformer, as he seems to think.
OK, one last time:
Check this out. Enlarge the photo of the instruction manual. Here it clearly shows the upper row as the four "U' posts.
The lower row is marked BOTH 1,2,3, and 4; AND A,B,C, and D.
According to Occam's Razor, it stands to reason that Lionel would have been much more likely to vary the printing of the "label" than to make internal changes in the wiring. Yes?
http://cgi.ebay.com/LIONEL-TYPES-V-and-Z-TRANSFORMER-OPERATING-MANUAL_W0QQitemZ190370472522QQcmdZViewItemQQptZModel_RR_Trains?hash=item2c52f6e24a
ADCX Rob and Bruce: The way I read your most recent posts, each of you is saying the exact opposite of what the other is saying. You need to work this out.
I vote for the top row being the commons, and voting, after all, is the American Way to decide things.
On a Type V transformer, the top row is the common. I believe the Type Z transformers are wired like a Type V.
In the pictures, you can see a wire going to each of the lower terminals, and a strap across the upper terminals.
Here is an easy way to prove how the transformer is wired. No meter is required.
Plug in the transformer. Set each of the the four control knobs to a different setting. Take a short piece of wire and touch one end to one of the top row of terminals, and momentarily touch the other end to another terminal. If there is no spark, these two terminals are common. If there is a spark, these are the variable outputs.
Ditto the lower row of terminals.
One row will spark, the other row will not.
lionel2I take it nobody has a Z transformer like this one. I have 5 Z's and this is the only one that is like this. It is very confusing. All the knobs have more than 22 volts going to each of them. So, I know it all is functioning the way it should. The green light does light up and it hums. The cord is flexible and pretty good. But, the 1,2,3,4 are right between the 2 rows of terminals, so It could be power for either the top or bottom row. I wish they would have labeled them with a U on all 4 of the right terminals. I hooked it up to my little 33 loco, with the U being on top and it worked just fine. I will try it again with a 167 direction controller. I have the directions for that as well, But not the Old Z. I have a set of directions for another Z, but the one with A,B,C,D. not 1,2,3,4. I will play around with it tonight and see what i can find out. thanks.
I take it nobody has a Z transformer like this one. I have 5 Z's and this is the only one that is like this. It is very confusing. All the knobs have more than 22 volts going to each of them. So, I know it all is functioning the way it should. The green light does light up and it hums. The cord is flexible and pretty good. But, the 1,2,3,4 are right between the 2 rows of terminals, so It could be power for either the top or bottom row. I wish they would have labeled them with a U on all 4 of the right terminals. I hooked it up to my little 33 loco, with the U being on top and it worked just fine. I will try it again with a 167 direction controller. I have the directions for that as well, But not the Old Z. I have a set of directions for another Z, but the one with A,B,C,D. not 1,2,3,4. I will play around with it tonight and see what i can find out. thanks.
11:50pm edit:
You are way over-thinking this. The upper posts are common, just like on your other 4 "Z" types, and all Type V transformers.
As you can see from the pic below, the knobs control the variable taps/posts, on the bottom row at the edge of the case, and the circuit breaker feeds the four common upper posts(out of view).
And, just to be sure you're clear on this, this transformer is just like yours, with "1-2-3-4" posts on the terminal block...
The transformer(Z & V types) would have to be re-engineered to switch the posts.
lionel2 I take it nobody has a Z transformer like this one. I have 5 Z's and this is the only one that is like this. It is very confusing. All the knobs have more than 22 volts going to each of them. So, I know it all is functioning the way it should. The green light does light up and it hums. The cord is flexible and pretty good. But, the 1,2,3,4 are right between the 2 rows of terminals, so It could be power for either the top or bottom row. I wish they would have labeled them with a U on all 4 of the right terminals. I hooked it up to my little 33 loco, with the U being on top and it worked just fine. I will try it again with a 167 direction controller. I have the directions for that as well, But not the Old Z. I have a set of directions for another Z, but the one with A,B,C,D. not 1,2,3,4. I will play around with it tonight and see what i can find out. thanks.
Lionel2, with all due respect I think you are making things harder than they actually are. Why do you suspect that the actual circuitry is substantially different among your several transformers. The photo in the link that I posted clearly shows the 1-4 labels between the two rows of terminals -- and nothing marked U. The repair man/proprietor at that site clearly has seen it before. Sometimes a little "outside the box thinking" is helpful.
Try the test that I suggested. If all else fails, open the case and see whether you can find a row of posts strapped together. If so, consider them to be common. There are other ways to test, especially since you have other transformers to try, but I won't go into them because sometimes they can be a bit exciting. Still, I think all questions will soon be answered. You may even find Jimmy Hoffa or Judge Crater in there.
That's all I have to offer on the subject.
Bruce, as long as the operator is consistent throughout the layout, and never confuses (cross-wires) what is common with what is not, I don't see how it matters; except as I have pointed out regarding whistle/horn and bell controls. Please explain your point in detail, with circuit diagrams, if possible.
I agree that the better way, for those still playing with blocks, is to use the outside rails as commons -- I always do -- but let's not confuse the basic issue for Lionel2, who hadn't even identified the common posts on his transformer last time I looked. OK?
Edit: added a space only.
It does make a difference how you connect a multi-output transformer. The U or common terminal must go to the outside rails. If you connect the U terminal to the center rail, and you have the track divided into blocks, you will short all the blocks together.
I suspect the top row, but it should be easy to check. Find the ohms scale of a multimeter. Unplug the transformer from the wall and remove all wires from all terminals on the rear. At rest, the ohmmeter should indicate an infinite resistance; that is, it should point to a little symbol that looks rather like the figure eight (8) lying on its side.
Touch and hold the two probes together, The reading should jump all the way to zero. Then start testing the terminals along the top row. Touching the first and second should once again cause the needle (or reading) to go to zero, as should the first and third; and the first and fourth as well. Then try the second and third, second and fourth. Indeed, all combinations along the top row should send the meter from infinity all the way to zero. The common terminals are all strapped together inside the transformer, most likely with a copper strip. That's what's meant by "common."
By definition, all common terminals are equivalent, so one is just as good as another. Not so for the "hot" or "power" terminals, of course, each one of which corresponds to a given throttle-knob.
If by any chance it doesn't work as I have described, try the bottom row. One row or the other should be house the commons. (If it still doesn't work, you have a problem somewhere.)
Once you have determined which row contains the commons, connect them to the outside rails of your track, per the convention that Lionel eventually adopted for its "multi-control" transformers; i.e those with more than one throttle circuit.
At the time your transformer was built, it didn't much matter which terminal you connected to center rail and which went to outside rail, as long as for each knob on the top-front of the transformer you selected one from the upper row and another from the lower one. With certain modern equipment it can matter a little bit, especially with regard to whistle/horn and bell operation.
I had questions about the Lionel Z transformer that is 250 watts from prewar Lionel. The bottom line is I just wanted to know which row of Terminals is the U posts and which row or terminals is the power terminals? The bottom or top row? Thanks.
If you are talking about the Z-4000 transformer, email MTH and ask for an instruction manual. I emailed MTH for a downloadable instruction manual for a PS-1 engine.
Lee F.
Are you talking about a Lionel Type Z transformer? There may have been early versions or variations under that name, or yours may have been repaired with mismatched spare parts, but all that I have seen had four U terminals and four other terminals labeled A, B, C and D.* They also had red and green plastic caps over the lamps.
Perhaps the link below will help -- if it works. The resident expert on Lionel Type Z transformers on this forum is Bob "lionelsoni" Nelson.
http://pictures.olsenstoy.com/searchcd31.htm?itm=669
* Intrigued by your question, I did some further research and found an interesting site at the link below. If you look closely, one "Z" transformer has only a single lamp (with a red cap) and uses the numbers 1 thru 4 to label the posts. You might contact the webmaster. You may be pleased to know that you are not hallucinating.
http://www.lioneltransformer.com/z_transformer_and_z_transformer_parts_for_sale
Hello, I have a Z transformer that I got last week and it is very odd. Instead of having the knobs and terminals in back labeled A,B,C,D. It is labeled 1,2,3,4. I have never seen this before. And the terminals in back are not labeled with U for the terminals. I would assume that the top set of terminals are ground and the bottom set of terminals are for power, is this correct?? Has anyone seen this before and could you fill me in as to why they are like that?? I am guessing it is very old and has no caps for the light bulbs on top plate. They are just colored red and green bulbs, small ones, 18 volts. Any help will do, thanks again everyone.
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