Model Railroading > Layout Wiring Question

I plan on building a 125 sq ft  DCC layout using a 12G wire for the main bus, 22G for feeders  and 18G for everything else. What  sizes(s) of Suitcase connector should I purchase.

Thanks
Wil 

This month's Model Railroader magazine has an article about that.  I will look it up when I have a chance and see what it says.

The 3M #905 suit case connector is for 14-18 AWG runs and 22-18 AWG taps.  THe #567 is for 12-10 AWG runs and 18-14 AWG taps.

They also mention 3M T-Tap connectors #951 for 22-18 AWG, #952 for 18-14 AWG and #953 for 12-10 AWG.

The article mentions products from www.allelectronics.com.  They have a 7300 for 12-10 AWG, the 7200 for 16-14 AWG anad the 7100 for 22-18 AWG.

Quite a number of people recommend using the genuine 3M suitcase connector, there are less expensive versions but they seem to cause enough mis-connections that it's worth the extra money.

I spent a lot of time shopping around for this style of connector, pretty hit or miss at most available hardware and big box stores. Then I realized Amazon was the place to find them, using the genuine 3M part number. There's also detailed technical info there.

I also recommend genuine 3M connectors. I used them on my layout for years without any problems and will use them again on the next layout when I rebuild at the new house. Just size the connector to the size of wire you are using. 

Hello, Rod Loder here, I introduce the 3M 567 "Suitcase" connectors to the Model Railroad World in 1989/1990 at Lee Nicholas UCW Railroad to the Prorail Group - In came the Big Guns - Say Sonny what's the Funny Little Brown things the Wires going into - some type of a Capacitor ? Well I step up to the Layout and gave them my speech - They all said "Damn - won't give HOT Solder dropping on you" Since then I put together the 32B Wiring method on Layouts at all kinds of Convenations and yes somebody always get up to say - they don't work worth a Hoot ! After talking with them and finding out their using the Cheaper Brand ("The Sweetness of the Price is soon Sorrowed by the lack of Quality") - I point out that 3M's have two pieces of Metal / twice as thick to pentrate the wires ! In Forty years as an Electrician by Trade using Thousands and Thousands of them - not one failure yet ! One tip before I stop typing - take several Feeders wires from the Track(s) and join them together with a Wire Nut and a Single jumper wire to the 567 - saves on the number of Suitcases ! Remember Model Railroading is Fun ! Over

As an electrical engineer, I can tell you that no suitcase connector is a relialbe as a good solder joint over time. Just my two cents. 

Scott Schifer
Torrance, CA
TinyTrains Website

I agree with Scott's comment about soldered connections. But my suitcase connections have held up for about 8 years so far. And it's so much easier than soldering above my head.

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The suitcase connectors work fine.  Just make sure you have inserted the feed wire into the connector completely before you compress the connection. 

309

I agree with Scott!

~RGDave
http://onondagacutoff.blogspot.com/

Would never use those type of connectors as you can quite often have corrosion occure between the connector and the wire where it scores both wires. I have run into this while doing wiring repairs on autos and trucks. Very hard to find at times and can only immagin with DCC the problems it could cause. Soldering is by far the best in the long run even with the chance of a cold joint, next best is butt connectors with a good set of crimping pliars, not Harbor Freight brand, and a little practice they work great.  Quick is not always the best way and after many hours of chasing lighting and other problems caused by those connectors I never use them no matter what. Also 14ga solid house wire is plenty even for G gauge buss track wire.
-------------------------------------------------------
> I plan on building a 125 sq ft  DCC layout using
> a 12G wire for the main bus, 22G for feeders  and
> 18G for everything else. What  sizes(s) of
> Suitcase connector should I purchase.
>
> Thanks
> Wil 

RE Corrosion when using suitcase connectors:  It's important to realize that the wiirng in autos and trucks functions in an enviroment that is MUCH different than a model railroad layout. 

What motor vehicle wiring has to contend with:  Huge temperature swings from below zero to over 100, moisture, vibration, dirt-laden water penetrating suitcase connectors, de-icing chemicals.  No wonder you see corrosion and failed suitcase connections in motor vehicles.  My experience is the suitcase connections typically sold at auto parts stores are the cheapie single-blade ones that are simply no substitute for the 3-M ones recommended above for model RR layouts. 

What model RR layout wiring has to contend with:  Relatively constant temperatures, no moisture, no vibration or movement, no dirty water incursions, no de-icing chemicals.  Even a layout built in an unheated garage is a better wiring environment than a motor vehicle.

There is a ton of real-world experince that proves that using 3-M suitcase connectors designed for the wire gauges you are connecting produces reliable model RR wiring.  Even with DCC.  But hey, don't pay any attantion to all those folks with reliable suitcase connector wiring.  Don't use them if you don't want to.   Enjoy the extra time you invest soldering under the layout.

- Norm

THANK YOU EVERYONE FOR YOUR OPINIONS


Regards

Wil
 

I think 3M suitcase connectors are fine for permanent in the basement layouts, but for modular use solder is the way to go due to vibration, temperature and humidity changes, and general handling wear and tear.
My two cents,
Clarence G
Free-mo modeler

Thanks for your opinion I will stick with other methods that years of experiance has proven much better. And by the way many have just the right enviroment to cause problems. Also using on single strand wire can nick it enough to cause it to break down the road when flexed.
I very much understand probalby more about connections than many do on here by the way. I worked on computer equiped transit coaches for years and strugglled with poor connections inside where the enviroment is much like a railroad room in a dry area of WA state.
We never used suitcase connectors anywhere for any reason. MANY times with them also you only make contact with part of stranded wire not all of it and how tight is the connection then?
-------------------------------------------------------
> RE Corrosion when using suitcase connectors: 
> It's important to realize that the wiirng in autos
> and trucks functions in an enviroment that is MUCH
> different than a model railroad layout. 
>
> What motor vehicle wiring has to contend with: 
> Huge temperature swings from below zero to over
> 100, moisture, vibration, dirt-laden water
> penetrating suitcase connectors, de-icing
> chemicals.  No wonder you see corrosion and
> failed suitcase connections in motor vehicles. 
> My experience is the suitcase connections
> typically sold at auto parts stores are the
> cheapie single-blade ones that are simply no
> substitute for the 3-M ones recommended above for
> model RR layouts. 
>
> What model RR layout wiring has to contend with: 
> Relatively constant temperatures, no moisture, no
> vibration or movement, no dirty water incursions,
> no de-icing chemicals.  Even a layout built in an
> unheated garage is a better wiring environment
> than a motor vehicle.
>
> There is a ton of real-world experince that proves
> that using 3-M suitcase connectors designed for
> the wire gauges you are connecting produces
> reliable model RR wiring.  Even with DCC.  But
> hey, don't pay any attantion to all those folks
> with reliable suitcase connector wiring.  Don't
> use them if you don't want to.   Enjoy the extra
> time you invest soldering under the layout.
>
> - Norm

If you ever want to create problems for your self, suitecase, (IDC's), Insulation displacement connectors, that's the 3M name for them, is the way to go. What they do is when you crimp them they will cut the strands of the wire. Also do not use house wire. House wire is 600V wire. There is to much resistance at low voltages due to the copper alloy for 600V wire. We used low voltage 30V landscape two conductor wire. It has lesser resistance at the lower voltage you will be at. As for connecting feeders to the buss I recommend strip and solder as we do at the La Mesa Club in San Diego or terminate with terminal blocks and ring terminals, it kind of expensive but solid as I do at the California southern here In Norwalk, Ca.
Steve Kelly. member LMMRRC San Diego, Ca, CSMRRC Norwalk,Ca.
ssk1047@aol.com     www.californiasouthern.org

Hello,

      I would recommend using no suitcase connectors and going with terminal strips. Much cleaner install and much better for troubleshooting. Just my experience.


                                                                 Best regards, Dave Dane  Mountain States Free-mo