Ground bar

You can hook them altogether at the transformers.

Thanks for reply John. Just for clarification are you saying the three transformers Cannot go to a single ground bar which I would think would effectively join them together  if I am joining them together at transformers instead does this mean each transformer should go to a separate ground bar for each and then on to devices

thanks

No, I was saying the commons can all connect together at the transformers, AAMOF, that's how I do it.  I have four PH180 transformers, and the commons are all bused together right at the panel.  I do run both hot and common out together to each drop for the best DCS signal performance.

@gunrunnerjohn posted:

No, I was saying the commons can all connect together at the transformers, AAMOF, that's how I do it.  I have four PH180 transformers, and the commons are all bused together right at the panel.  I do run both hot and common out together to each drop for the best DCS signal performance.

Lots of Lionel power!

Ok. So Ill run each transformer to a ground bar dedicated to that transformer and from there to its several devices   I will then run a ground wire between the transformers common ground posts

thanks as always John. Attached is a pic of a weaver Osgood Bradley that I relighted with one of your LED kits and filled up with people

All the commons on my layout are tied together. I just used a Wago lever nut to connect everything. The grounds from 2 TIU channel outs, the U post on the TMCC base, and the wire that goes to the layout common are just all connected at that Wago nut, Easy peasy.

Wvm

Actually a better term that is used for model trains is "Common" that would better describe its function.  Of course the transformers have to be phased.

Charlie

You don’t need a “Ground Bar.” Just connect all the “U” terminals  together at the transformers. Presto…you now have a “ground bar” also known as a Common Ground.

Rich. Yes but I am using the ground bar as follows  one lead from common post to a ground bar and then from there to all of the various track drops    I had been asking whether I could use a single bar to come from all transformers commons and from that bar to all drops you can see answer is no

@Wvm posted:

Ok. So Ill run each transformer to a ground bar dedicated to that transformer and from there to its several devices   I will then run a ground wire between the transformers common ground posts

That is essentially a single common bus.

@Wvm posted:

I had been asking whether I could use a single bar to come from all transformers commons and from that bar to all drops you can see answer is no

Aren't you describing something like this? Forget about the TIU in the picture. I run two PH 180s and tie them together at these oversized, jumpered barrier strips. These are track feeds. The two screws at either end are for connecting accessory transformer commons and/or Legacy (if I ever get the chance to add it.)

You can use a ground bar, sky wire, anything you like.  All the commons can indeed connect together at the transformers any way you see fit to connect them.

Hate to beat a dead horse to death but The reason I brought his up is as follows

on my control panel I installed a single long ground bar to attach all grounds(outside rails, grounds from Ross switch machines etc) and then to this bar I attached wires from all transformer commons   I thought this would work but ran into following problem

I am using KW transformer posts D and C to provide 14 volt for switches.  C being ground. When I attached the C wire to the ground bar ( so I could have non derailing function on tracks supported by other transformers) the KW immediately shorted and tripped

i have come to the conclusion that effectively grounding the KW posts U and C together creates a short   The good news is I have found that if I attach the the 14v C ground  to a separate dedicated bar and then onto all the switches every thing is working fine I get the non derailing function by having all the transformers common posts tied together at the previously mentioned single ground bar  (minus the C post)

sorry if I am being confusing  I think some of you might find this interesting and help me better understand why it is  working this way

Well, the mystery is solved.  You can't do that and have a common ground as the C & D posts are not at the potential of the U posts!  The idea of a common ground is solid and how virtually all layouts are wired.  However, you're simply misusing the transformer, my advice is "don't do that"!

I personally think having two commons at different potentials on your layout is not a great idea, I'd just use a different transformer to do the switches if you want separate power, problem solved.

John

I can use the KW for 14v switches using the C and D posts  for switches only but I still have to tie it together with the track transformers in order to implement non derailing. (Through common U post on KW)

Are you saying that I can’t use a KW even as a dedicated accessory transformer because it’s 14v posts are a different potential for accessories than it’s own variable track voltage of 0 to 20 volts or other transformers I might use for tracks Do other transformers like the the LW deliver 14v at an acceptable level

I thought I had solved my problems one I had kept switch grounds separate

Thanks for staying with me on this one

Give me a call... it's way faster to talk ...than type.

No, if you JUST use the KW for the switches, you can make the C or D posts the common(dependent on phasing), the whole point is that you're trying to use the U post as the common when for this scenario it's not the common if you're using C and D as a power source.

Don't use a too small wire (larger gauge) for your common wire from everything back to your transformers.

Gary all my wiring is 14 Ga on an 8 x 14 table  star wiring no run longer than 8 ft. Should I be ok?

More than OK!  I have a 12 x 24 layout wired with #14, and wiring capacity has not been a problem at all.  I have minimal voltage drops, even with some fairly healthy loads across the layout.