A different (i.e. better?) IDC

[Anonymous]

A different (i.e. better?) IDC

IDCs (Insulation Displacement Connectors) have been discussed here many times before.  Tony Koester uses them (see August, 1998 MR).  Allen Gardner has some words of caution when using IDCs: (see http://www.wiringfordcc.com/track.htm#a17)

Bear with me and I might be able to shed some new light on IDCs.  In both cases referenced above they were referring to the typical "suitcase" connectors as is shown below from the Mouser catalog:

However, on the bottom of the same Mouser catalog page (http://www.mouser.com/catalog/631/1283.pdf) you will find T-TAP disconnects:

And on the next page of the Mouser catalog (http://www.mouser.com/catalog/631/1284.pdf) you will find various male blades such as:

I have found that using these two items may solve a number of concerns expressed by Mr. Gardner.

1. You can mix the tap and blade size to match the wire gauges that you are using.

2. You do not need to unclamp the T-TAP to disconnect the drop wire. By its very nature this is a disconnect-able assembly which can be great for troubleshooting.

3. The T-TAP size is more suitable for using a conventional tool (pliers) instead of a specialized crimping tool.

4. If one of the two parts fails or gets damaged or has a bad connection you do not have to replace both (Functionally both).

I have just begun wiring my new layout using these T-TAP connectors so I can NOT speak from extensive experience however I have done some testing and I have put together a few pictures to show how they look in real life:

The picture above shows how they would be used under a layout.  The bus wire is 12 gauge and the feeder wires are 20 gauge. 

The pictures below are close-ups of the individual parts:

 

A few of installation notes that I have discovered so far:

 

• 1. If you use a pair of pliers, use only pliers with a wide surface such as the large RoboGrips shown in the picture. Pliers with a small face may bend the T-TAP connector.
• 2. I have found it easier to "pre-set" the 12 gauge wire into the T-TAP jaws with a light squeeze of the pliers before closing the case and making the final squeeze to lock the tap into place.
• 3. I also find is easier to disassemble the insulated male blade, as shown in the picture, and crimp the un-insulated blade body. Then slide the insulation back up over the connector.

 

Finally, if you have a concern about long term corrosion using IDCs, then a dash of Dielectric grease (oxidation inhibitor) on each contact will solve this problem.

http://products3.3m.com/catalog/us/en001/auto_marine_aero/aerospace/node_GS9NWKSQZTbe/root_GST1T4S9TCgv/vroot_GSNNJ6NQDKge/gvel_S3PQPD4JXXgl/theme_us_aerospace_3_0/command_AbcPageHandler/output_html

You can find dielectric grease at your home center or hardware store.  It is used in residential/commercial wiring when joining two types of electrical conductors (i.e. aluminum to copper) and is also used extensively in boating and automotive wiring.

Obviously I will do anything to minimize my time "under the table."

Good Luck,

-John

 

[exPalaceDog]

Interesting Post!!

 

Thanks for the info

 

have fun

 

[rrinker]

 That does look to overcome the issues of the 'standard' tap connectors. But silly me, I'd probably still solder the male end on the feeder wire.

   I still think the most flexible approach, although probably the most costly, is to use terminal strips and rather than run a continuous bus break it up with terminal strips at key point to tie the feeders to. The advantage is you can tap out whatever might be required to go back adn add detection and so forth without leaving any extra 'junk' clamped to the wires. And the cheapest but least flexible way is to simply solder the feeders to the bus.

 

                           --Randy
 

 

 

[loathar]

Great! Where were you 6 months ago when I was on my back soldering all my feeders in place??
Those are neat. I've never seen a connector that let you join a 20 to a 12.

[UP2CSX]

Don't go any further until investigate Posi-Tap connectors. You can add up to four 20 gauge wires to one tap and you can tap off anything from a 10 gauge up to a 16 gaugewire. The whole thing needs no tools of any kind. The resulting connection is both electrically more sound and many times stronger than a soldered connection. I've just completed adding 59 different kinds of lights to my layout and the whole thing took about three man hours including drilling the holes. I'd never use anything other than Posi-Tap connectors again. No connection with the company but the inventor should be given a Nobel Prize.

[Anonymous]

Very interesting.  A Posi-Tap connector does look like a nice device.  However, the manufacturer specifies stranded wire for all of their Posi-Products including the Posi-Tap (http://www.posi-lock.com/newproducts.html).  I am sure this is due to the center punch design of their primary tap (http://www.posi-lock.com/instructions1.html).  If you are using stranded wire then the Posi-Tap may definitely be the way to go but I would be a little concerned about using these devices for solid wire -- especially on DCC bus work.  For low current draw lighting I can see where Posi-Taps could really be a timesaver.

 Thanks for the tip.

-John

[UP2CSX]

John, my bad for not realizing you're running a power buss around the layout. The Posi-Tap does work on solid wire but it's not as reliable as the system you're using. Once you get to the stage where you start running stranded wires for lighting, signals, and such, do give the Posi-Tap and Posi-Loc a try. It saved me a world of headaches getting my layout lights wired.  

[60YOKID]

I really like the design of those Posi-Taps! Perhaps you could use #12 stranded for your main track buss.  It can be a little kinky unless you fasten it pretty often, but twisting it helps too.

On the other hand, I have no need for a so-called "main track buss". 

On my HO layout I used individual #18 stranded/twisted/jacketed cable runs.  These all originate at my central Digitrax booster location, and go out to each block. The "blocks" use two or three #20 dropper wires.

This has worked great for 16 blocks and each are about 25 feet long.  I am getting ready to install the current detectors next. 

I use a 5 amp power supply and have operated 10 DCC engines of which 6 have sound, without any problems or noticable speed reductions.

As I expand, I plan on adding another booster near the center of the new expansion area. 

-Just another way to skin the proverbial cat!

-Bill