TMCC/Legacy Ground Plane Pain . . . . Advice Needed On Ground Plane Wire Installation

Thanks for viewing this post and making suggestions !!

I am building a multi level layout with two or three parallel tracks on each level. I am planning to install ground plane wires and would love some advice.

1) I cannot connect to the house water pipe as an earth ground. Is it sufficient to connect to the "green" ground screw of the nearest electric receptacle?

 Theoretically, yes, but you would be better off buying a replacement three prong plug from the hardware store and connecting the wire to the ground prong .

2) Assuming I can have the primary ground plane wire emanate from the wall receptacle, can it be connected to a terminal strip and then distributed around the layout as needed?

Yes. Solder the connections if you can, or make sure they are clean and solid.

3) Should the ground plane wire underneath the upper level be "zig-zagged" all the way around the layout?

Your choice. Zig-zagging will put more wire in more places, so that might help, but I do not think it is necessary. It certainly will not hurt.

BTW, It's unfortunate that we have been calling it a ground plane, when it is really the antenna, but it's too late now to get into that discussion.

4) Should the ground plane wire be placed in between every parallel track on all levels?

I have no clue about that. It depends on if the loco has a relatively clear shot at the "ground plane".

5) Does the gauge or quality of the ground plane wire make a difference?

Not really. The wire need only be thick enough to be mechanically stable. The current it carries is infinitesimal, so gauge is not a factor - except it has to be thick enough so that it does not get broken easily. Do not use shielded wire. That will defeat the whole purpose.

Many, many thanks for suggestions !!

Scrapiron

Howdy Scrapiron,

 +1 on the info from ROYBOY.  I have a similar situation and here's what I did.  In the area where I have the 2 lower main loops running under the elevated upper main I installed a 16 gauge stranded wire in a Zig-Zag pattern directly above the 2 lower main loops.  This wire was stapled to the 1/2" plywood sub roadbed.  I was also experiencing signal problems with my Fastrack O72 Command Switches so I ran a 28 gauge wire between the inner and outer lower main loops to the locations where the problematic O72 Fastrack Command Switches were located (there were several).  I ran the wire along the straight side of the switch (the side with the program button) as close as possible to the Fastrack roadbed so the ballast I will add later will help hide the wire.  Do not run the "Ground Plane" wire under the switches because I'm told that the metal plate will block the signal.  I have a special 3 prong plug that has been altered so there is no connection to the 2 spade prongs (hot and return) but it has a green 14 gauge wire connected to the round "ground" prong.  The green wire from this plug is then connected to a terminal block which distributes the "house ground" to the layout.  I have not tested the effect of the "ground plane" that runs over the lower 2 main loops below the elevated portion of my layout, however, this method sure did cure my signal problem involving the Fastrack Command Switches.  Also, as a side note, My house was built in 1956 and uses "Knob and Tube" to distribute electric power throughout the house.  Therefore, on the advice of a friend who is an electrician, I installed GFI's in the basement where the layout is located and this is where the "Ground Plane" plug goes.  I certainly do not know how this set-up works, but it does.  All that being said, first check with a Licensed Electrician before you do anything.  I am not offering advice or instructions.  I am merely stating what worked for me.  In other words, Do Not Try This At Home without consulting a Licensed, Bonded and Insured Professional Electrician.  Good Luck my Friend and keep us posted!

 Chief Bob (Retired)

Thanks to both of you. I will use the ground prong you suggested. 

Scrappy

I have aluminum foil tape under all the track. Here is a picture under the layout that shows the tape under 5 tracks on the lower level The screws and wires that make contact with the tape for connection back to the electrical ground pin are also visible. this works great on a complex 3 level layout.

The actual connection to earth ground is a real puzzle for me. Went to HD and they have no plugs I can solder a wire to. Closest is the three prong gizmo you see below. Can I not just tie a wire around that green ******* screw and have done with this? Water pipes not near the layout, GFI outlets around the corner in very visible areas. I am getting so frustrated. Something that should be so simple ......

Hi Scrapiron,

 Yep, that will work.  Just make sure that there are ABSOLUTELY NO WIRES CONNECTED TO THE HOT AND RETURN CONTACTS OF THE PLUG!  I used a 3 prong plug from an old DE-humidifier that had a short length of wire still attached.  I isolated the two wires going to the hot and return by cutting them flush and adding shrink tube to the ends.  I then attached a wire to the ground prong only.  Hope this helps!

 Chief Bob (Retired)

Chief Bob (Pufferbelly), You made my day !

Scrappy

Scrappy,

That's what we do.  We help each other and that's what makes this forum such a great asset to this terrific hobby.   BTW, I used a Green wire (12 or 14 gauge should be OK) from my "Ground Plane Plug" to my "Ground Plane Terminal Block" just to keep things simple.   Again, good luck and let me know how you "Git-R-Done"!

Chief Bob (Retired)

We ran the TMCC antenna extension wire the full length of the upper level, one continuous wire, plugged into the green ground hole in a wall plug.   Used 24 gauge wire.  Hot-glued it to the side of the sub-roadbed, so it radiates the signal down to the lower tracks.  Works GREAT!

Didn't need one in the six-track yard, or anywhere else on the layout.  

No TMCC signal problems at all anywhere.

DCS didn't care .. continues to work fine.

The wire is on the edge of the upper level in the photo.

Much easier to tie the ground wire to pin 5 of the Command Base serial port - which is the actual reference for the TMCC earth ground.

From the late Dale Manquen: TrainFacts

That metal screw, center of a duplex receptacle, that holds the face plate, is grounded.  Replace the screw with an ever so slightly longer #6 round head screw.  Use an I-let connector.  A metal receptacle plate would be a plus.   You don't even have to remove the plate from the receptacle.   IMO, Foggy head,  Mike CT 

Mike CT posted:

That metal screw, center of a duplex receptacle, that holds the face plate, is grounded.  Replace the screw with an ever so slightly longer #6 round head screw.  Use an I-let connector.  A metal receptacle plate would be a plus.   You don't even have to remove the plate from the receptacle.   IMO, Foggy head,  Mike CT 

Why not just stick a plug into that ground plug hole in the wall receptacle at the end of the wire?  That's what worked for us.  Easy, simple and looks "clean."

I have had a multi level TMCC layout for twenty years with virtually no problems,  I recently converted it to Legacy, by installing a Powermaster Bridge, so I could continue to use my TMCC Powermasters. The upper level, approximately twelve by fourteen feet covers a significant area of the lower19 x 26 foot main level. There is also a lower level subway, beneath the main level.  My ground wire is a single loop around entire layout. It is solid, not stranded 14 gauge UNINSULATED wire.  There are drops from the Gargraves track and accessories to that ground wire, spaced throughout the layout.  When building the layout, I read about this set up in one of the early books about TMCC.  I think, but am not sure that Peter Riddle was the author.  Of course I cannot use my Cab 1s or the TMCC Base.  The Legacy Base, and transformers are plugged into a grounded power strip, which in turn is plugged into a grounded wall outlet.  I have installed,  on all five power and ground wires coming off the Powermasters, in-line fuses.

Goody posted:

My ground wire is a single loop around entire layout. It is solid, not stranded 14 gauge UNINSULATED wire. 

FWIW, there is zero reason for having UNINSULATED wire, or for that matter, using heavy wire for the earth ground line.  You can use any size wire, and insulation won't change anything about the signal.  The earth ground would work just the same with #30 insulated wire as with #14 uninsulated wire.

Hello, Scrap Iron--

Here is something that you should look into, and which can still be done, even if you have finished your new layout in large measure.  The thing is, if a short occurs on the circuit from which you "emanate" your green ground,  you will get some kind of voltage rise on the house green ground wire for that circuit: 1) it can rise to above the 30-volt "hot" touch limit; 2) it can rise to 63 volts on a 125-volt day; 3) it can rise to more than that if the wiring was done in the days when the green wire did not have to be the same size as the hot wire; it can rise to 125v if the green wire does not continue back to the panel or if it has been connected to the hot wire.

I presume you would have detected the last condition, but if you worked with that breaker off, you might not have.  For the other conditions, keeping the insulation on these ground wires is excellent advice from Gunrunner.  What is happening is that with new houses, the interior is spray-painted with the boxes open and the wires hanging loose.  So all the color-coded wires are some shade of white where you see them for hook-up.   A problem?  Yes, who'd'a guessed.

Now you mentioned that you have ground fault circuit interrupter devices (personnel protection?) (GFCI-5ma?), which have been required in unfinished cellars for some time.  Remember that these come in higher amperages (-10ma for a freezer at times?), as well if those things are actually arc protection breakers with included GFCI (required with finished cellars AND a rare required retrofit--lots of controversy here), and that will be 20 to 40ma.  Now 5ma will knock you off a ladder, and I am not allowed to say here what 30 ma will do.  Initially some of these may have been downstream of panels, but that may be passe now.

I assume when you say you have GFCI's, you do and know you should test them monthly, and they are in the first outlet, feed-thru type.  But others reading this may not know.  And if you do not know the wiring history of the house, you too.  So you have GFCI's on a circuit.  This can have two meanings.  First, you have 3-prong outlets supplied from a 3-wire circuit, and you are compliant with the GFCI in unfinished basement area, and all you have to worry about is if you decide to put a nice floor and some rugs in your layout room aisles.

Second meaning, it may be that someone has accommodated three-prong plugs by changing all the receptacles, while still having only a 2-wire circuit.  This is permitted if the basement is unfinished and the circuits have GFCI added (this can also be done by getting a GFCI breaker taking only two spaces, twice or 4 times if you have the piggyback 15amp breakers).  It is actually a more personnel protective solution than a grounded circuit from a regular breaker, because of the speed with which it operates.  In any case, $2000 will usually fix you up with a new panel or sub-panel, which you usually need for arc breakers upstairs.

I cannot help you with arc breakers, except to say you only have 4 choices, and the range of the included GFCI is 20-40ma, depending on which manufacturer you choose.  If you have a bare concrete floor, 20ma will be very bad or worse, and anything should be backed by standalone GFCI-5ma, IMHO.  Here in Virginia we will be 3 years behind at least, adopting the 2017 NEC sometime after May 2020.  This situation requires consulting an electrician to get the  latest on the advances in technology, at the planning stage.

It is also possible to isolate the connection to house green ground by using a ceramic capacitor.  There is a class of these rated for personnel protection, which will IIRC pass about 1/10th of the ground plane (cellar floor, etc) current generated by the TMCC wall wart.  Of course, the 2017 NEC was worded to newly address the issue of making and repairing plug-in equipment, another controversy.  Code changes are made between 3-year cycles at times.

--Frank

Dale Manquen provided the clearest explanation of the TMCC signal on his trainfacts.com website.  The Lionel patent drawing that shows the RF signal radiating from the outside rails is bogus.  The outside rail, and the loco chassis, is the ground side of the signal at the LCRU in the loco.  The output from the TMCC/Legacy base goes to the grounded pin of the power brick (and to pin 5 of the serial connector if you choose to tap that).  This turns the ground wire of your house wiring, or your water pipes into the broadcast antenna.  Since grounded wiring is present all around the layout room in most homes, the TMCC signal propagates well and the loco's receive antenna can detect the voltage differential between the rails and over the air signal from the wall wiring/pipes.

Signal reception problems arise when the broadcast signal from the wall is blocked or absorbed by the outside rails, overhead tracks, high density yard tracks, metal bridges, wire reinforced tunnels, etc.   The solution is to extend the broadcast antenna into to areas where locos are not receiving the signal.  This is accomplished using wire or metalized tape.

I was asked to get TMCC working on a large layout with 5 levels with many metal bridges and tunnels.  The TMCC signal was weak or absent in many sections.  After looking at the challenge of retrofitting a fully scenic-ed layout with limited clearance between levels, I decided to use metal tape instead of wire.  There wasn't enough clearance to use a staple gun to affix a wire on the underside of elevated sections, and a visible wire on the top surface was not desirable.  Aluminized duct tape was purchased at the local hardware store, and for tight areas, 3/8" copper tape was ordered from the river.  The tape glued nicely to the underside of the plywood elevated sections.  Since this was a tinplate layout, track screws passing through metal ties to metal bridges needed insulation so long 3mm black nylon machine screws and nuts were ordered from the river.  The track over metal bridge decks was insulated with grey carpet and the plastic screws held the track in place.  After insulating the bridges, they were connected to the ground plane.  Wire drops from the bridges and tape to the under-table ground plane wire were made at multiple points.  At every step in this process, separation of the ground plane and outside rails was verified with a multimeter.

The process of retrofitting a fully scenic-ed layout is a PITA.  Looking back at the process, I might lean towards wire instead of tape, and get some gaffer's tape to affix the wire on the underside of the deck.  I spent a lot of time making wire jumpers from tape to metal bridges and then screwing the jumpers to the tape on the underside of the elevated deck.  Using wire would cut that effort in half - just snake the wire through a hole in the deck and connect to the bridge.  For a new construction where the elevated deck undersides are accessible before installation, tape is easy and fast.  When installing the ground plane, your multimeter is your friend.  A single short to the outside rails kills the effort.

I'm curious ... has anyone tapped the serial output pin 5 for the antenna and run ground plane wiring directly from pin 5 without using the grounded power brick?

Tracker John posted:

The process of retrofitting a fully scenic-ed layout is a PITA.  Looking back at the process, I might lean towards wire instead of tape, and get some gaffer's tape to affix the wire on the underside of the deck.  I spent a lot of time making wire jumpers from tape to metal bridges and then screwing the jumpers to the tape on the underside of the elevated deck.  Using wire would cut that effort in half - just snake the wire through a hole in the deck and connect to the bridge.  For a new construction where the elevated deck undersides are accessible before installation, tape is easy and fast.  When installing the ground plane, your multimeter is your friend.  A single short to the outside rails kills the effort.

Dale also pioneered another development that really helps in many of these situations.

For my layout, the signal enhancer from GRJ and Dale was the best solution.  I had fastened wire under the layout and that was a true pain and only helped a little,  but there were still some locomotives which I could not run.  Once I got the booster, all problems were eliminated.  I was able to remove all of the ground plane wires and the control did not regress .  I do not have complex overhead tracks but a lot of parallel especially in yards.

Marty