Is my 12 gauge ground wire enough for my layout?

By the way what gauge of wire should I use for the main Center rail power?

If you join the ends of your loop, then the distance to the farthest point is only about 50 feet thru TWO #12 ga wires. Since the current spec for wire ga is based on a single wire 100 foot run, and #12 is spec'ed for 20 amps, I think you are fine.

Also in the related thread, some mention of wire color was recommended as a standard. The example given was for ac house wiring. This is not that. You can of course use any color which allows you to determine which wire is which. I use red/black zip wire 12 thru 18 ga for all the wiring on my layout. I think you should run both wires "hot" and "common", a pair of 12 ga wires, everywhere you supply power on the layout. I don't understand running just one wire.

BTW, you can leave that solid wire in place and connect it to pin #5 of the DB9 connector on the Legacy base to possibly aid in TMCC signal transmission after you run the pair of power wires.

 The ground buss has to take the sum of all the amperage of all the transformers hooked to it. On a large layout,voltage drop is also a consideration. 3 ZWs is around 30 amps. Output on each ZW is around 200 watts,call it 20 volts at 10 amps.   A 12 gauge wire is good for 20 amps, maybe 25. I would add a second #12 wire,but what you have will probably work since the 3 ZWs will not be maxed out. It is really not size but the electrical load on it.

Dale H

I agree with cjack about looping the ground.  That's what I have done with my 12-gauge solid ground.

I agree, loop the #12 Common return.

With the size of the layout table, I would suggest 14ga wire for the power, and use star wiring for the common and the power wire. This way, there is the same power to the track on the entire layout. I would also suggest Lionel's Legacy system. 

I would block off the layout with Lionel's BPC's, through the TPC 300's for Conventional and TMCC Legacy use.  I would have as many blocks as necessary.

My layout is 17 by 38 feet, 5 level, and we use 14ga wire for all the power and commons, via 5 BPC's for train control....We use the ASC'S for all the switches and the accessories.....Its Fun....Good Luck

Jerry A,

   More than adequate, 14 would have been just fine, 12 Gauge stranded might just be over kill!  Loop if you like.  Also use the 12 track join discipline and build in blocks for running both DCS & Legacy.

PCRR/Dave

Disagree, Dave.  If there's a single ground loop running around a large layout, with all outside rails and accessories connected to it, as I have, you can be pushing many amps through that wire.  I do agree on 14 gauge for hot feeds to blocks.

Great information and thanks MUCH!!!!!

I have only laid the 12 gauge common around the layout at this point. I do plan on connecting them over the  hinged bridge to connect the common loop.

Please advise the next  step regarding where to add the power wiring. and please advise or  better yet attach a sketch of how a star connection should look like with the power and common leads.

Thanks, jerry 

If you'll be running conventional, optimal operational flexibility can be had by dividing layout into relatively small blocks, each with a single 14-gauge center-rail hot feed coming through a toggle switch on the control panel.  "Star-wiring" and the ground bus, as you and I have, are 2 different methods. 

My layout, 37x16, was so designed and built in early 90's for conventional, to operate several trains at once.  DCS was added about 2001 or 2002 when it came out.

Do be sure to have an adequate number of 14-gauge ground drops from the 12-gauge bus to outside rails. If using Gargraves track or equivalent, connect outsude rails together unless using one for signalling.

Thank you sir !!

Jerry