RW Transformer configuration -- stay with center rail common and outer rails hot?

[CliffhouseNY]

Looking for opinions -- wondering if I should follow the factory instructions for my RW transformer and connect the common to center rail, or go with the more typical center-rail-hot/outer-rails-common format most people are using now? 

I recently discovered much of my father's old train set -- we thought everything had been lost in a house fire, but an assortment of locomotive and cars had been stored in another location. Survivors include 225E, a 2020, a 51 Navy Yard, and a 1654 and an assortment of pre-war and post war freight cars.  Also a box of signals and other accessories.  The ZW transformer was not so lucky.

I've purchased a re-built RW transformer and set up a *very* small layout for testing and experimenting for now.  Not 100% sure where I'm going to end up, but for now I'd like to set up some remote switches and control signals as part of the learning process.  

I was really puzzled resolving my instruction manual manual and everything else I read or watched until I figured out some of the single train transformers were intended to run with center rail common.

Wondering if it makes more sense for me to go with center rail hot just to get in the habit? If nothing else, it would make everything I read and watch on YouTube easier to understand and implement.  I have a small brick transformer I can use for the accessories, and I realize I'd need something bigger/newer if I built things out for multiple trains or newer locomotives.

Am I overthinking this?  Do I just go with RW instructions as written and not worry about the swap until I get there?  The current layout is absolutely not something that would be incorporated into a larger layout -- I've intentionally built it as something temporary that will be tossed at some point.

Thanks for any wisdom/bias/opinions you have to share!

   

[trainlivebob]

It really doesnt matter if you just have a simple layout, one transformer and one train. But I would use center-rail-hot/outer-rails-common convention.  Never did the other.  

But the confusion is with Lionel transformers.  They were not consistant in labeling their terminals.  Some commons are labeled U and others A or B or ?  I dont have a RW but Im guessing U post is the "hot" post.  This may be causing the confusion.

[ADCX Rob]

CliffhouseNY

Looking for opinions -- wondering if I should follow the factory instructions for my RW transformer and connect the common to center rail, or go with the more typical center-rail-hot/outer-rails-common format most people are using now?

...

Am I overthinking this?  Do I just go with RW instructions as written and not worry about the swap until I get there?  The current layout is absolutely not something that would be incorporated into a larger layout -- I've intentionally built it as something temporary that will be tossed at some point.

Thanks for any wisdom/bias/opinions you have to share!

You are making an error in fact here - on the RW "A" is common, not "U". This is not opinion.

So yes, the "U" goes to the center rail. It has the whistle & direction controls in its circuit... if you try to use "U" as common, you will shut down the entire layout, not just the train track, every time you hit the direction button.

[ADCX Rob]

trainlivebob

...the confusion is with Lionel transformers.  They were not consistant in labeling their terminals...

They were very consistant.

Single throttle transformers use "U" to lockon clip 1 for the center rail, and usually "A" is common.

Multi-throttle transformers use "U" to lockon clip 2 for the outside running rails / common.

[CliffhouseNY]

Thanks for the clarification!  From the videos I've seen I had the mistaken impression that U was synonymous with "common". 

Glad I stuck to the manual... for a change.  

[trainlivebob]

And I hooked up my 1033 wrong for 60 years. 

I thought U was common for all lionel transformers in my mind.  Just switched it, but for my layout it made no difference.

[stuartmit]

I am very interested in this discussion. I am 79 and love to play with trains, but knowledge is only to a certain level. It was only recently that i noticed the U terminal is preferred for comnmon on multi throttle, but not on single throttles.  I dont know why they did that, although i will concede the info is there in the instruction books which came with sets in the late 40's and 50's, although I dont think they pointed it out.

I have been succesful with 2 RW's and a V wired together. I connected all U terminals together, and to the running rails as common. The center rails are connected to the other terminals a, b of the RW etc., and perhaps A,B, C and D on the V for some constant voltage blocks for special climbing situation, or constant voltage plugs for 022 switches and a circuit to power track control relays.

 

the following from Rob is very interesting

 if you try to use "U" as common, you will shut down the entire layout, not just the train track, every time you hit the direction button.

That effect never made itself apparent to me. Is there something better I could do? I rarely use the directional control; my eunits are all locked for forward running.  My desire is to be able to run two trains over the same trackage in dufferent directions simultaneously. This is quite a burden on my attention as operator, and is not completely fun.

 

suggestions?

[ADCX Rob]

stuartmit

the following from Rob is very interesting if you try to use "U" as common, you will shut down the entire layout, not just the train track, every time you hit the direction button.

The other problem if you use "U" as common, is that the whistle signal goes to the entire layout, accessories & all, instead of just the intended center rail.

stuartmit

I connected all U terminals together, and to the running rails as common. The center rails are connected to the other terminals a, b of the RW etc., and perhaps A,B, C and D on the V

You lucked out somehow. RW "A" common posts should be phased with Type V "U" common posts.

[CliffhouseNY]

Thanks -- That makes me feel a little better!

I went back to my Greenberg manual and found the table outlining the various circuits for all of the postwar transformers -- both RW and 1033 are listed there.  I was interested to see for the RW are rows showing posts A and B as common, but there is also a row also listing voltages when U is used as common.  Using A or B as common allows you to also connect post C and D to get fixed voltage (6/9 & 16/19) with the circuit with U delivers variable voltage.  If U is used as common, then the only option is variable voltage with A or B posts.

I'm guessing this means for a layout with a single transformer it's okay to use U as common as long as you don't plan to use C or D for supplying fixed voltage to any accessories.  Or use a second transformer with its own common bus for accessories?

I'm going to stick with B as common for my layout and use red wire for hot and black for common -- if I ever upgrade to something like a ZW transformer, it seems like it should just a matter of matching up the wiring to the correct posts.

That sound right to you, Rob?

  

[stuartmit]

Can smart use of RW's and my V remedy the following? My transformet setup, described above is 2 Rw's connected to a V with all U terminals connected together. I observe my 773 seems to run uphill more slowly than I would expect with a load of 6 postwar freight car. there is no other load on this transformer; other loads are a 2343 on a different RW, and perhaps 15 -20 O22'switches with controllers on the V. But I believe the only relevant transformer is the RW (110watts) that powers the track blocks on which the 773 runs. 
could I improve by swapping the voltage source for the blocks through which 773 runs to the V which goes up to 25 volts? To do that I would move the switch power source to the now available A output of the R. 

I also have available an SW.a TW, an R and another RW.,

[ADCX Rob]

CliffhouseNY

found the table outlining the various circuits for all of the postwar transformers -- both RW and 1033 are listed there...

Here is the entry:

So, yes, single train single track no accessories it makes no difference.

But if you do it right from the beginning, you won't have to revisit the issue when you expand and get unwanted/unexpected operational problems.

Note also that although there are many combinations listed here, some of them have no circuit breaker protection. On the RW, D-U, A-C, A-B, and B-C do not go through the breaker.