transformer post being able to be depressed

Maybe, it acts as a reversing switch.

@jim sutter posted:

Maybe, it acts as a reversing switch.

It is the reversing switch.  Jim nailed it.

I am not an electrician but you never disconnect the ground and leave the 'hot' post active.  It will just start searching for a ground.  Now if it blows the horn while not disconnecting the ground then I assume all is fine.  Anyone know?

It is indeed meant to be a direction button, some even had a plastic nut on that button like on this one;

https://www.fatmansgarage.com/...ultivolt-transformer

As I said in the other thread my brother and I are working on him building a temporary layout. This is one of his trannie’s.

I can’t wait to tell him it’s a reversing button

Thanks guys I really appreciate it

- walt

It enables the E unit.

What model transformer is that?

When I got home looked through my box of transformers. I have a 4561 that works that way, so that is one model.

@Bill DeBrooke posted:

I am not an electrician but you never disconnect the ground and leave the 'hot' post active.  It will just start searching for a ground.  Now if it blows the horn while not disconnecting the ground then I assume all is fine.  Anyone know?

Lionel AC transformers are not grounded. They are safe because they are isolating transformers. Grounding 120 volt electricity makes you halfway safe and using a ground fault interrupter along with grounding makes you safe on the other half. But toy train transformers have been safe for the past 100 years (long before the use of ground fault interrupters) because they isolate us from the 120 volt power line and they reduce the power to only 18 volts.

So why do people use the word "ground" in relation to 3-rail toy trains? A better word to use would be "common" for the connection to the outside rails. If you are using a ZW or KW transformer, that "common" would be terminal "U", but this does not apply to all Lionel transformers. Since Lionel was not consistent with terminal "U", we all are scrambling to describe that outside rail connection. You would be correct about the horn blowing being important in the outside rail connection, but not in this case. This transformer is for an entry level train without whistle or horn, so which terminal is used for the outside rail with this transformer is irrelevant.

Now if you have two or more transformers on one line, then phasing becomes important.

@walt rapp posted:

What is the purpose of having the post being able to be depressed?

A review of the operating instructions furnished with these sets will reveal it is simply a method to trip the reverse unit for direction control.

The more basic sets deleted even this feature if no reverse unit was in the train, or requiring a sweep of the lever for direction changes.

@Bill DeBrooke posted:

I am not an electrician but you never disconnect the ground and leave the 'hot' post active.

The throttle wiper on these basic set transformers is connected to the left, fixed post, & the reversing & breaker(if equipped) is on the right post. You make the call when using them on common ground layouts.

@Ross posted:

What model transformer is that?

It's a 4050/4150 derivative 4851. Low power with reverse button.

@John in California posted:

If you are using a ZW or KW transformer, that "common" would be terminal "U", ...

This applies to all multi-train transformers.

For single train transformers, the rule is "U" to the center rail, and usually "A" to the outside, common rails, with "B" or other posts for lower output voltage settings to the tracks.

A lot of questions can be answered by the expenditure of $25 on Amazon to purchase Greenbergs Repair and Operating manual for Lionel Trains, 1945-1969.  Everything you need to know about transformers is included, and this transformer is on page 537.  Prior to 1945, Tandem Associates online  has a lot of info, but after 1969, you have to do some hunting and asking.

@CALNNC posted:

this transformer is on page 537...

This 4851 transformer is not in the Greenberg book, but is very similar to the 1010 & 1025 on which it is based.

@ADCX Rob posted:

A review of the operating instructions furnished with these sets will reveal it is simply a method to trip the reverse unit for direction control.

The more basic sets deleted even this feature if no reverse unit was in the train, or requiring a sweep of the lever for direction changes.

He bought the black trannie at a train show - no manual of course.

I searched for info hoping to find a manual or similar.  I came up empty.  I'm just not very good at searches.

My red one (as shown above) came in a basic starter set bought in 1974 (a gift to me),  There's no manual with it.  I can't recall if the engine in the set can reverse or not because I don't use it on my Christmas layout every year.

as always - thanks

walt

Well contrary to my opinion to use the "base" post as the common, Lionel it seems, in 1975 anyway, recommended using the wiper/throttle posts of these small transformers for phasing into common ground layouts.

As long as you set the convention for your layout and stick with it, there should be no problem.

all things electrical always seem to get complicated.  I know what I know, what has worked for me for years, and I "TRY" to ignore the more advanced, oft times, confusing stuff (to me).

But I do want to continue to expand my knowledge of the basic stuff, like with my brother's starter set trannie from which I learned HERE what it can do.

as always, thanks

walt