Linking transformer commons

How about using an open bus bar such as that used in the breaker panel in your house?

They are very robust, inexpensive, and can handle the entire rating of your breaker panel; ie 200 amps or so.

Shorter ones are available that have maybe 8 or 10 holes with massive set screws on each. Each hole can handle several wires in the 8, 10, 12, & 14 AWG size range. there was a picture of one in a recent post.

On my layout I use several Curtis barrier terminal strips. They come in a 1500 series (15 amps) and a 2000 series (20 amps). I believe there is also a heavier series available that is good for 30 or 40 amps. You could Google it.

Rod

George

Are these DZ-2500 mometary powered just to throw the switch or constantly drawing current?

It is hard for me to believe that even 21 switch machines are going to be drawing 40 + amps at any one time

Common bus bars (3)

I am with pennsyk- the connected load is one thing, the average load is quite another

Thanks, guys.

Charlie, the Lionel 180s are for track power.  The soon to purchased 5th transformer will run the DZ-2500s.

Mike, looks like those bus bars have plastic mounting clips attached.  Are they necessary or can I attached the bar directly to plywood?

George

That is what I did on my common on the three sections of my layout.  I took a brass wood screw and two brass counter sink washers and screwed it into the particle board or plywood in the center of each section on the underside.  I ran a length of #16 wire from each block to the screw and stripped 2 inches off and twisted it between the washers.  When done, I tightened the screw down.

Charlie

Hi Charlie

Your use of the screw method is sometimes mentioned in another forum by Bob Nelson. It should work IF you have phased the transformers, ran a wire from the transformers to each of the three locations - directly or by daisy-chain - to bring the common to all of the locations. I am not sure why you chose 16 AWG for the "40 amps", 14 or even 12 romex might be a better choice to bring the power to the screw heads. 16 AWG is a bit lite for 40 amps, IMHO.

Others are hinting at a separate bus for the DZ2500s. I believe the common you have put in place for the track power will provide the common you need for the non-derailing function. You now need a common for the motors themselves and 40 amps seems a bit much. These switches operate momentary and at about 14V, somewhere in the 10-18 that Zstuff indicates. Hooking these switches to your track bus may not be wise. If you ever plan to use the DataDriver, you will need the bus anyway. INHO, keep the switches separate.

I'm sure others will chime in,

Ralph

Wake Forest RR

I'm not sure of your circuitry? Wouldn't you be paralleling four 10 amp PoHos to result in 40 amps of concentrated power?? The separated channels of barrier distribution strips, even those from Radio Shack, will handle 10 amps. As I understand it , you will be distributing 10 amps to four separate districts---not one?

Grouping "common "commons on a bus bar for developing  a "Layout Common" is different from distributing hot railpower to 4 different districts or "blocks".

The (40 amps) is interesting. I like to think of it as (4) (10amp) loops that touch each other with (4) 10 amp fuses somewhere in each of the (4) loop circuits, most likely on the Power/hot side of the loop..  So somewhere off that common buss there would be (4) wires capable of 10 amps each back to each transformer. If one of these wires is open/disconnected I'm not sure what would happen.  Maybe the ability to load up the other three return paths if the one transformer works at all.

If you connect all the Power/hot wires, off the (4) transformers, on the other side of the loop, the same way the commons are connected, you now have a 40 amp system. (Paralleling power supplies).

The electrical panel busses pictured could easily handle 100 amps.

Dewey,

Yes, each PoHo will run a separate disctrict.  Thanks for the "heads up" on connecting the commons together being different from connecting the hots.

Mike,

I will avoid linking the 4 PoHos together.

If I may pose another question, should I connect the 5th transformer common tasked with running the DZ-2500 switch machines and push buttons to the track power common bus?  I do plan on using the non-derail function of the switch machines.

Thanks,

George

A good rule of thumb for figuring load is to always take the total load times 125%
So if you had a 40 Amp. load figure a rating of 50 Amps.

Some may not agree with me but if your phasing transformers together AND tying Commons together it's a good idea to fuse or protect each common where it's connected to each individual transformer.

If you've got all your commons tied together and you have a short it's gonna go back on each common leg to each transformer and it may not  ever cause a problem but you know how it goes ... Never say never.

David