When in doubt, read the instructions

I have all of those transformers and have studied the schematics and pictorial diagrams from the Lionel service documents.

Your instructions are all correct.

I have seen some, very little, reference to why it was done this way, but the convention for postwar transformers(and continuing with the 4090 after 1969) is:

-single train transformers all have the throttle, direction, & whistle controls connected to the "U" binding posts for use on the lockon clip "1" or center rail
-multi-train transformers all have the throttle, direction, & whistle controls connected to other than "U" binding posts(A,B, D, e.g.), and "U" is for use on the lockon clip "2" or outside rails and is common in reference to the other posts on the transformer.

Interesting point Rob, that the distinction is between the single- and multi-train transformers.  Your advice is always spot on as is most on this forum. Lots of great contributors here. Sometimes l just google a question and have learned that's a 50/50 gamble when it comes to O Gauge.

Label your wires this year.

  You can buy wire numbering labels or use a pen and some masking tape (pencil will fade in time) 

  Hopefully you know to phase them if you do use multiple transformers.

And I have heard the 1033 transformer has a "floating ground".  What does that mean?

Here's an example of just "going to the web" and getting bad results (I think).  I will attach pictures from the original instruction sets, but from what I can tell, this guy's post is wrong on the 1033 and RW but correct on the LW and TW (of the 4 single-train PW transformer types I own). 

My read from the instructions is:

LW, RW, TW: Variable/Hot = U (to center rail); Common = A (to outside rail)

1033: Variable/Hot = A (to center rail); Common = U (to outside rail)

http://www.jwtrains.com/tech%20tip_6.htm

Photos of 1033, LW, RW, TW connections.

raising4daughters posted:

http://www.jwtrains.com/tech%20tip_6.htm

He has the 1033(chart) & 1044(pictured) right with U (to center rail) & common A (to outside rail), but the RW is wrong. It could be a "ringer", but more likely just an oversight or typo/mixup.

raising4daughters posted:

This is wrong!

They even went out of their way to make it wrong by crossing lines/wires when the correct connections are so straightforward.

Never go to the internet to get answers about trains.  Always go to OGR Forum.

Dennis

ADCX Rob posted:

raising4daughters posted:

This is wrong!

They even went out of their way to make it wrong by crossing lines/wires when the correct connections are so straightforward.

Alright Rob, I'll trust you as you've never steered me wrong before, but it's so frustrating even going back to the source and finding out it's been wrong for 60+ years.

For my layout, I'm not sure how much it matters (which may be revealing my ignorance). My understanding for pre-electronics age engines was that mixing up the A and U, say, just prevented the whistle from working but the engine and lighted cars would function. I'm guessing there's more danger with modern stuff.

I have one 1033 connected to my ceiling layout's lights. I'm using the variable voltage with the throttle as my on/off switch. I'm guessing I'm safe with that one either way, but will go back and put the U to the hot and A to the common since it shares a common bus line with two RW transformers. The RWs are connected two independent loops using PM-1 Powermasters.

On the RWs, I connected the fused wire to the U post and non-fused to A like you suggested. But, out of the PMs, I went A to center rail and U to outer rail.  Right?

My other 1033 is connected using fixed voltage to three accessories through a switch bank to operate my milk car, merchandise car, and cattle car.  I keep these off the mainlines so they can always be played with. I'd have to go look, but I think I used the A-C for 16V.  In this case, does it matter which post (A or C) goes to the center rails? No electronics involved.

There are actually numerous ways that these transformers can be connected to the track and work perfectly.  The important thing is to understanding which binding post you are using as the Common/Ground/Outside Rail and the resulting voltages available at the other binding posts.  The below chart is a good reference found in the 1965 How to Operate Lionel Trains and Accessories for"027" "O" and "Super O"

can't you just tell if you blow the horn and the bell goes off that the wires are crossed?

raising4daughters posted:

On the RWs, I connected the fused wire to the U post and non-fused to A like you suggested. But, out of the PMs, I went A to center rail and U to outer rail.  Right?

Correct - this will keep the DC offset in the right polarity for whistles & bells. This all assumes that the RWs are phased to each other and to any other transformers used for train/rail power, to prevent either shorts, or 36+ volts on the tracks.

raising4daughters posted:

My other 1033 is connected using fixed voltage to three accessories through a switch bank to operate my milk car, merchandise car, and cattle car.  I keep these off the mainlines so they can always be played with. I'd have to go look, but I think I used the A-C for 16V.  In this case, does it matter which post (A or C) goes to the center rails? No electronics involved.

If it's not used for train control, it really doesn't matter, it doesn't even have to be in phase(you will know right away with accessories if phase becomes an issue - the performance would be an unexpected no-go voltage or twice as high voltage, or the throttle will seem to work backwards) although for keeping wiring organized & straightforward it helps if you continue with common ground/return conventions.  Although a rare occurrence, if you use "U" as common on the 1033/1044, it's possible that the entire current/load of the entire layout could be routed through the transformer(and the throttle/whistle circuit) if someone trips on a cord or some wires get knocked loose buy a derailment or bump, and there is no circuit breaker on "U"(it's on A & B).

   Another reason to be conscious of common and hots would be any acc. items using the frame/base/structure for power routing, being near enough to the track that the acc. may get shorted to the track via bump or derailment. E.g. a metal lamp post that carries a power leg I'd match the lamp base's power leg to the outer rail, & the other legs wire lead to the center rail.

Lionel wiring instructions are simply proof that they are meant to be adult toys. Every time my wife complains that toy trains are for children, I hand her a copy and ask her to figure it out.

Bogie

Adriatic posted:

   Another reason to be conscious of common and hots...

All good points!

There are advantages to having transformers out of phase in large layouts that use a tremendous amount of power and/or have long wire runs in order to reduce voltage drop. Those of you familiar with the NEC & household or commercial wiring know what I mean.