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Electric Wire connectors

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Electric Wire connectors
Posted by Curt on Saturday, January 24, 2009 10:25 AM

Hi,

I am still kind of a rookie at this model railroading but want to learn to do things the best and right way. I thought I once heard of a electrical/wiring product called tap-in or tap-ons use to connect wring. I thought they were able to be used to tap in to the middle of a bus wire for example and then be able to run other wires off that. Could some tell me if I am thinking of the right thing and where is a good place to purchase them. Is there a good place online or can I get them at a Lowes or Home Depot?

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Posted by claymore1977 on Saturday, January 24, 2009 10:47 AM

 Talking about these?

 

 

Dave Loman

My site: The Rusty Spike

"It's a penny for your thoughts, but you have to put your 2 cents in.... hey, someone's making a penny!"

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Posted by tstage on Saturday, January 24, 2009 11:30 AM

Curt,

I believe what you are describing are called "suitcase" connectors or, more properly, Insulation Displacement Connectors (IDC) and look like this:


They can be found in the electrical departments of either HD or Lowe's.  The best ones are made by 3M (Scotchlok) and can be purchased from Micro-Mark in packages of 25.

Since IDCs come in different sizes, the KEY thing to using them is to make sure you are connecting them to the PROPER size wires.  For instance, 3Ms #905 (pictured above) fit 14-18ga buses and can accommodate 18-22g feeders.  That's a pretty good range for most folks.  Take your time and size your wiring to whichever IDC is going to work best for you and vise versa. 

Curt, I have IDCs connected to my 14ga power bus and run 18ga feeders from them to terminal strips.  My track feeders - 20ga - run from my terminal strips and is soldered to my track.  This makes both wiring and any troubleshooting later much easier.

I also use crimp "U-shaped" connectors at the ends of my wires that are connected to my terminal strips.  Since I'm more likely to move and jostle these around over time, I choose to both crimp AND solder the connectors to the wires.

Curt, the other thing when using IDCs is to make sure you crimp them correctly.  While the larger hole (for the bus) can be positioned anywhere along the bus that you want, your feeder wire needs to butt right up against the stop in the smaller hole.

There are two sets of notches (one for each wire) in the crimping tab that will cradle the wires as the metal tab bites through the insulation.  When you crimp, make sure that the crimping tab ends up flush with the top of the IDC.  For crimping, I use a pair of Sears Craftsman RoboGrip pliers.

Sorry for the long-winded response.  Hope that helps...

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by cmrproducts on Saturday, January 24, 2009 6:16 PM

 

Any type IDC or Suitcase Connectors are trustworthy if -

1. They are installed with the PROPER tool !

2. They are SIZED for the PROPER Wire Gauge that is being connected together !

3. The person installing them has had the proper TRAINING !

4. The environment that they are installed in is free of vibration and excessive Temperature and Humidity changes !

Now with that said -

1. Not EVERY modeler is going to go out and purchase the proper tool - most cases they just crimp them with a pair of pliers !

2. Most modelers do not realize that they make a number of different sizes to connect the many wire gauges together and fewer modelers will spend the time to ask the sales person for a recommendation on the proper connector !

3. When has a man ever read the instructions let alone listened to anyone talking about proper install techniques ;-)

4. Few basements are climate controlled let alone a 2 stall garage! 

Miss any of the above recommendations and the connector will FAIL ! 

While it might not be tomorrow or next month or even next year - it WILL FAIL !

Now if you do not plan on keeping the layout around a long time (years) then go for it but I know first hand that they fail after while.  It took 3 years for our CLUB O gauge layout to begin having problems and I was the one that put in 90% of the connectors.  They would fail intermittently and trouble shooting the problem during open houses with paying visitors was not an option!

Our next layout has ALL connections soldered and we have ZERO problems and ZERO maintenance to the wiring.  We (the CLUB) have finally learned a few things in our 25 year journey!

BOB H - Clarion, PA
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Posted by jrbernier on Saturday, January 24, 2009 7:58 PM

  3M 'Scotchlock' IDC's can be purchased through on-line electonic places like Mouser or Digikey.  If you use them, make sure you get the right ones for the size of bus/feeders you are using  I have them on my home layout and have had NO problems in over 5 years.  We used them and Posi-Lock/Posi-Tap connectors at the club about 3 years ago.  I have marked off the areas where we tried different brands(including 'wire nuts') and I still have not found any problems with any of the connections.  I have used a RRampMeter to measure DCC track voltage around the club layout and have not found more than .1 volt difference(some of the bus runs are over 70' long and go through a PM42).  The layout fills up a 27' square room(two levels).  Lowes or HD might have them, but you are going to pay through the nose for them.  I bought mine from Mouser(about 18-20 cents each in quantities of 100).  I use the #905(#18-#22 wire for the 'tap', and #14-#18 for the bus).  My 'bus' is #14 solid wire(residential), and my feeders to the 'tap' are #20 stranded wire soldered to the rail every 3 feet.  I have about 150 sections of flex track in the layout and I went through almost 400 IDC's.  Here is the web link to Mouser Electronics:

http://www.mouser.com/Search/Refine.aspx?Keyword=3m+905

Jim Bernier

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by desertdog on Saturday, January 24, 2009 8:13 PM
I switched from the 3M IDC's to Posi-Tap connectors and would never return. There's no need for any special tools, they install much more easily and in under a minute. In five years, not one connection has loosened up or failed. John Timm
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Posted by cmrproducts on Sunday, January 25, 2009 7:53 AM

 It seems funny that most everyone complains about the cost of building a layout yet spend more money on things like the IDC connectors vs a roll of solder.

On my layout I have over 1500 wire drops and at a minimum of .05 cent a piece (if I ever could get them at that price) for the POSI Taps/suitcase connectors/IDCs would run me over $75.00 (they are more on the order of .25 a piece - $375.00).

While a 1 lb roll of .032 60/40 solder is $15.00 from online sources - I believe I would rather spend the lesser amount and KNOW that I had a more secure wire connection and put the left over money into more engines or rolling stock.

But then again that is YOUR problem not mine ;-)

BOB H - Clarion, PA

 

 

 

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Posted by tomikawaTT on Sunday, January 25, 2009 11:00 AM

This is the second thread on suitcase connectors in as many days.  Rather than completely reiterate my previous post, I will simply say that my thinking is heavily influenced by a career in aircraft maintenance.

Any aircraft electrician who installed a suitcase connector would be decertified faster than you can say, "improper procedure,"

My personal preference is for stud-type terminal blocks, which I assemble in whatever configuration is needed from 8-32 machine screws, nuts and washers mounted through heavy styrene (acquired by dumpster diving.)  I install them along the aisle, behind access panels in the fascia - no standing on my head under the benchwork, thank you...  There is no reason not to run bus wires along the aisles unless you have a layout width measured in yards.  My maximum rail drop length, rail to terminal block, is about 24 inches.  Drops are soldered to the rails.

(I also mount switch machines along the aisles, but that's a different subject.)

Chuck (ex USAF Quality Control inspector modeling Central Japan in September, 1964)

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