Wire Tapping For Dummies?

This is a picture of what I consider to be a T-Tap (the blurry one) and a picture  of a suitcase connector.  I am using what I have and prefer the T-Taps over the Suitcase type connectors as with the T-Taps, one can remove the lead up to the track and then replace it as necessary if one is doing trouble shooting. 

As far as looking for "Shorts/Opens", the most beneficial diagnostic tool is the VOM, Volt/Ohm Meter.  I have several for various reasons but anyone working with Electrical problems should have at least one.

To further my information to you, I am assuming that you did not run both the Black and Red wires from the Atlas Connectors to the same Suitcase connector as if you did do that would be the case of your "Short".  One, preferably the Red lead should be run to your HOT BUS wire and the Black lead to your Neutral/Ground BUS wire.  Your HOT BUS wire would be a run from the Lettered Terminal of your Transformer (i.e. A, B, C or D).  The Neutral/Ground BUS wire should be run back to the "U" Terminal on your Transformer. 

Hi Jim. Thanks so much for the reply and pointers. No, I didn’t run the red and black to the same suitcase. The way I did it was I wire tapped the black atlas connector coming from the transformer and ran that new wire about 6 feet away to another black atlas connector. Same method for the red. Then I would repeat this scenario, tapping off that 2nd set of Atlas connectors to the third set. Do you have any ideas of where I’m screwing up? Best Chris

The concept when the members here say they want to "minimize voltage drop" is to use a concept of BUS (also seen of this site as BUSS) wiring.  It would appear that you are using a concept more aligned to "Daisy Chaining".  Without actually seeing your wiring I can only interpret your wording.  Here is what in my opinion you should be doing.  The larger the wire in physical diameter and Smaller the AWG number is what you should run from your transformer all around your layout, no breaks.  I suggest STRANDED wire.  Two wires are required for this. One wire will be your Hot side connected to the Lettered terminal on your transformer.  The second wire will be your Neutral (also seen on this site as GROUND) and it is also run around your layout from your "U" terminal on your transformer.  If you have the courage you could make both of these wires 12 AWG STRANDED.  However 14 AWG Stranded is adequate for your size (12x12) layout.  Once you have these two wires run, then use the suitcase connectors to attach you Atlas drop wires, both Black and Red, to the appropriate BUS wire.  I on the other hand prefer the use of T-Taps as the connector of choice.  Here is my reasoning for this.  Your BUS wire is going to be much larger diameter than the Drop wire from your Atlas joiners.  I have never found a suitcase connector that can accommodate the variation in your two wires.  On the other hand I have seen and have used T-Taps that can be attached to the larger BUS wire with the male connector that plug into the T-Tap that can accommodate the 18 AWG wire on your Atlas joiner.  As I indicated before in this thread, the Red drop wire would connect to Your Hot BUS Wire and the Black drop wire to your Neutral/Ground BUS wire.  One further suggestion is to go to your local Big Box Hardware Store and purchase colored jacketed wire.  Again I suggest Black for your Neutral/Ground BUS wire and Red colored jacketed wire for your HOT BUS wire.  I only suggest these colors since they mate up with the colors of the Atlas connector wires.  And one more thing to make sure.  Sine the Red jacketed wire is your Hot side, this wire should go to the Connector used for the center rail.  The Black wires should go to the connector you use to join the outside rail.  Now thinking ahead and not knowing how involved you will get with this layout, You can use the Atlas Joiner with the Black wire to either outside rail.  The Alternative is to maintain the same Rail as your Neutral/Ground return.  I mention this since there are some on this forum that use a concept of "Insulated Rail" to activate accessories as a Train goes over a particular area.  If your saying "HUH" at this point, dis regard the Alternate explanation.  And finally, I have tried to be simplistic in my explanation only because I am not familiar enough with you to know your depth of knowledge in electricity.  If I have insulted your intelligence, please accept my apologies.

I am sure I have planted more questions in your mind than answers to your situation.  So others may jump in and clarify anything I have raised questions with my wording.

Hi Jim. Amazing, thank you so much for the detailed reply. I do understand a lot of your explanation. But I might be off track (no pun) right from the get go. When you say “is what you should run from your transformer all around your layout, no breaks...”, how is this done? I’m accustomed to just running one set of the red and black Atlas joiners from the transformer to one section of track.

Jim

A very timely post, for me anyway. Just started final track drops and bus(s)bars. Appreciate the detailed response.

Steven Taylor

@Madlove posted:

Hi Jim. Amazing, thank you so much for the detailed reply. I do understand a lot of your explanation. But I might be off track (no pun) right from the get go. When you say “is what you should run from your transformer all around your layout, no breaks...”, how is this done? I’m accustomed to just running one set of the red and black Atlas joiners from the transformer to one section of track.

If I remember correctly, you are doing a ceiling layout around a 12 x 12 room.  As I said go to your big Box store and get One (1) each spool of 100 feet of Black jacketed and Red Jacketed wire.  Attach one end of the two wires to your Hot and Neutral (Separately of course) to the Lettered and "U" terminals on your transformer (I have been assuming that your transformer is more than the little transformer usually sent in a set like a KW or a Z).  then wit a good staple gun or staples and hammer attach the wires to the bottom of your "Shelf" all around your room.  Now when you get to the end essentially where you started, you can do one of two things.  I usually just because of my layout, I crimp on a lug terminal and through screw the lug to the bottom of the layout just to give a finished look.  However, it is also acceptable to terminate the end of your wire back on the same post as at the beginning of the run. If you request the explanation of this last idea, let me know and I will explain some electrical theory to you.

Now that you have Hot and Neutral available on your entire layout, You now have the ability to Tap in to the BUS wires using T-Taps into each wire with the drops from the Atlas joiners.  Using a large diameter wire prevents excessive voltage drop.  if you ran lets say 26 AWG as your BUS wire and you went to the far extent of your room you would notice a difference in the voltage measured at the transformer and at the farthest extent of the run.  The reason is that electricity has a harder time running in small diameter wire.  Hence the resistance of the smaller wire just eats up the voltage along the run.

Now are you going to be running accessories?  If yes and they all use approximately the same voltage, run a third BUS wire around your layout as with the previous Two.  I suggest a separate jacketed color just to keep everything straight.  When you wish to hook up an accessory, drop the accessory wires down through your shelf and attach the Hot side lead of the accessory to your Third BUS wire and connect the Neutral wire of the accessory to the Neutral of the original Neutral BUS wire.  This assumes you are using a single transformer that has a variable voltage terminal for your non-command engines and a Fixed voltage terminal that you attached the third BUS wire to.  All Neutrals of a single transformer are common.  Just to be sure please inform me of the transformer you are using or plan to use.

I think that is enough of Wiring a Layout 101 for tonight.  Keep me posted.  I am going tomorrow to take a couple of picture of the T-Taps I used.  I think that will be beneficial for you.  Now I do need to express a caveat.  There are some purist on the forum that stay 100 miles away from crimped on connectors and swear up and down that a solder connection is the only way to go.  I do see in some cases their point(s) but i have never had a problem with either crimped-on-connectors or soldered joints.  But since you began this thread with the use of Suitcase connectors, I continued in that vein.

I should have added that the short run from the BUS wire up to your Track using that 18 AWG Atlas wire will not insert any measurable voltage drop hence many here on the forum use large gauge such as 18 or even 20 AWG wire for these short runs and they are easier to hide than 14 AWG wire on the top of the layout.  Accessory wire is generally 18 or 20 AWG anyway.

Jim: You did it. I get it now. Sorry it took so long!  I will work on it and post some pics when it’s running. It’s interesting because I’m not doing a ceiling shelf layout. It’s more of a suspended track around the room. I built about 22 suspension modules out of wood and metal. I think it looks cool, sort of modern which are the two trains I have, the Railking NYC Aerotrain and the 3rd Rail Mercury set. Thank you again for all the effort. Chris

Just getting into the rack and saw your reply on my phone. Two questions that I would like for you to answer. What transformer are you contemplating using? Are you running Command or Conventional?

I’m using a Lionel ZW with 2 180w transformers I bought twenty years ago. I’m running conventional. All my train stuff is from 20 years ago, when I had a basement. Now I have the 12 x 12 room that I have a slot car track set up. Over the years I’ve taken the trains out for my boys and we did a floor layout for the day. A few years ago my Mercury’s axel snapped and I put it aside to be repaired but never did. A few months ago I finally sent it off to 3rd Rail’s repair guy. I’m awaiting its return. I was going to do a stationary rollers set up for it but then it dawned on me...what about the ceiling? I was able to use my 99 curves which should be nice with the Mercury. It’s been quite an undertaking, lots of planning and building for a relatively simple thing. C

I am back home and as I stated I would take some pictures of the connectors that we have been discussing.  In this first picture I have already departed from the subject sentence to give my understanding of color coding of various electrical connectors.  This picture shows three "Lugs".  Disregard the type of connector and draw your attention to insulation color: Yellow, Red and Blue.  There is a rhyme and reason for the colors the Yellow is for a smaller diameter and the Blue is for a larger diameter wire with Red being in Between.  So the question may be asked how to accommodate all the wire sizes of the AWG?  This is done by repeating the color codes, as in for AWG's of say 24 down to 20, you will see Yellow, Red and Blue connector sizes.  For AWG's 18 down to 14 again the connectors would be seen with the same sequence of colors and again likewise with AWG's of 12 down to 8.  I can only assume that who came up with this color coding assumed that the user would have a sense of the very small barrels for a series of connectors, bigger sized barrel connectors and the large diameter wire connectors and even larger Barrels.

In this next picture I have attempted to show the difference in the barrel size.  I wish that I had thought to show two different size barrels each having Yellow insulation to make clear what I am alluding to as repeated colors.

Apparently the yellow size is not apparent due to my amateur Photography.  But i think the Red and Blue are apparent.  These connectors are from the top 18 AWG (Yellow) to 14 AWG (Blue).  Now back to the T-Taps, remembering the Color coding is carried through out.

This picture shows the T-Tap that would be applied to the BUS wire and again albeit I don't show all the colors, if you would be using 14 AWG STRANDED wire, select the BLUE size T-Tap.  Now what is important is the Female area of the T-Tap. You will notice that there is a Male connector of a certain color also.  This is so one can connect an 18 AWG wire (Yellow) and plug the male connector into the Female insertion point of the T-Tap (Blue).  The T-Tap (lower line) is applied to the BUS wire and crimped on.  Once applied it appears as a "T".  The Male connector is crimped on to your Drop wire and plugged in to the Female acceptor of the T-Tap.

I did not have any 18 AWG (Yellow) Male connectors to show you.  Again the reason I like this type of connector versus the Suitcase Connector is the ease of disconnecting and re-insertion for trouble shooting.  I also took a picture of a suitcase connector.

Again the color code is through out.  This is the 14 AWG connector.  The BUS wire is inserted close to the front and the wire to be connected (Drop Wire) in the back area.  Another draw back to this connector is that the same size wire is required for the use of this connector.  Somewhere in the back of my mind I believe there are mixed AWG sizes for this type of connector.  I leave it to the reader to investigate the reality of this phenomenon.  Also for the area where the wire would be inserted that would be the "Drop" wire is a "Stop".   Make sure that you insert the wire in correctly (from the right as the connector sits above) where both wires will be connected when the metal crimper is compressed into both wires.  I perform this function using a pair of Plumber's Pliers.  This allows for equal pressure through out the compression process.  I then snap down the lid on the "Suitcase" (Hence the nickname of the connector) and the connection is complete.

One final caveat!  I have stressed in this thread STRANDED wire.  These crimp on connectors should/must not be used with SOLID wire.  Can it be done? I would assume so.  But I suggest if you do wish to try, you do it with care.

Question re suitcase connectors, is it one size for all gauges  of wire or are there different sizes of suitcase connectors.

Thank you

The connectors come in different sizes. It is possible to cut wires or not make contact if you have the wrong ones. They also do not work well with THHN wire, as I found out personally. A terminal strip, Posi-Tap, or Wago connections are much easier to disconnect for additions or trouble shooting.

@Steven posted:

Question re suitcase connectors, is it one size for all gauges  of wire or are there different sizes of suitcase connectors.

Thank you

So I just did some preliminary investigation as to the reality of my memory by going to Digikey.com, an Electronic Supplier.  I searched for "Suitcase Connector".  Investigating the results, I did not see an item that stuck out to me that would allow for the use of different gauge wires.  I just retired to my basement shop to see the embossing on the Blue Suitcase connector I have.  I found that the Blue suitcase connector I have is specified for 18 - 14 AWG.   So the specification on the connector would lead me to believe that a size wire in that range can be accommodated in either the front (BUS wire) or back (Drop wire) of the connector.  Also the Blue T-Tap I have is specified for 18 - 14 AWG.  So I need to retract the statement I made regarding the color code traversing all connectors.  But, basically it holds for Lug type terminals that Blue AWG are specified for a given size (14 AWG), Reds would be for a given size larger AWG (16 AWG), and Yellow are for a given size larger AWG (18 AWG).  And then likewise for Lugs beyond these AWG's and below these AWG's.  My caveat is to understand what you are trying to accomplish and then look at the type of connector you wish to use and then refer to its specifications to make a final determination of the correct product to use for your application.  Also note that the LARGER the diameter of the wire the SMALLER the number for AWG.  I have tried to be explicit in this discussion whether I am referring to wire diameter or the AWG number.

Sorry for the confusion I may have introduced but we have in our lifetimes there are exceptions to the rule.  Again sorry.

From large wire to small: yellow, blue, red.

Someone once said "A picture is worth a thousand words". This is my final word on terminal insulation color code. Yes John your statement is correct.

Thank you for this info!

Thanks to Jim and this forum, as Johnny Cash would say, I hear that train a-comin. Still working on some acrylic guard rails.