"Suitcase" Connectors

I am planning on using suitcase connectors to wire my layout, and have a supply of the pink IDC’s (#558) on hand. I am working with N scale Kato Unitrack and their feeder sections use 24AWG wire, which I would like to connect directly to the bus wires running under the layout.

The #558’s are apparently designed for 16-22AWG sizes, so my question is would the pink suitcase connectors work with the smaller Kato supplied 24AWG wire? I could always solder the wires if necessary but the IDC’s are a much more convenient option.

I rather doubt it. I have #905(red) suitcase connectors. The are set up for #14/#18 bus and #18/22 feeders. My #14 bus wiring fits in them perfect. I tried to use #22 feeder wires, but they were just too small for the 3M brand Scotch-Lock connectors to made a reliable connection. I happened to find a LHS that was going our of business and got a good deal on spools of #20 wire(I think it was Atlas). When you get into small wire sizes, the diameter of the insulation makes a big difference You can always use a ‘butt’ connector to transition from you #24 Kato wire to something more reliable if you find that you have problems with the connections. I would setup a test of the proposed wiring with typical runs of bus wiring and several IDC feeder drops and take voltage reading to see if there is a problem.

Jim

There is a reason they are illegal to use on an aircraft.

They should be illegal to use on a child’s big wheel car.

One advantage of the suitcase connectors of course is the mechanical process of connecting beneath your layout, versus soldering there (though people do that as well). If you don’t have tons of 24AWG feeder tracks, perhaps consider a 2-step approach: soldering a piece of 22AWG feeder extension at the workbench, covered by a piece of shrink tubing to insulate. Then use the suitcase connectors under the table, connecting the 22AWG to the buss wire. I used the 3M 558 connectors successfully with 16AWG stranded (from Lowes) feeder and 22AWG solid feeders (from Hobby Engineering). Strongly suggest not buying off-brand IDCs.

Not quite a fair comparison to a train layout…

Aircraft…lots of vibration, varying temperature extremes and pressures, and often miles high and often several hundreds of miles from a place to land, and lastly their not FAA approved bc they probably arent safe in the above conditions for years buried inside an airplane’s wiring bundles.

Train layout…very little vibration, temperature nearly constant depending on location, and always stationary.

I fly airplanes for a living and have a medium sized train layout. I know a thing or two about both. Comparing the practical uses of a suitcase connector with these two examples is not a logical argument for or against them.

With that said, I used them to connect 22awg feeders to my track with solder and connected to the14awg bus wire with 3M suitcase connectors. Works fine,quick and easy. No shorts, failures, or fires. Would do it just the same again if I was to do it over.

After chasing intermittent power losses on a prior club unit that used suitcase connectors til I was blue in the face, we finally got permission to kill layout operations for a few weeks til each and every one of them was eliminated, soldered and taped. Funny thing,the problems disappeared!

Never again will I use them. A physical connection as a proper splice is the ONLY permanent wire repair!

.

I’m currently wiring my 15’ x 16’ HO layout and the IDC 905 red connectors have been a godsend connecting #22 solid feeder wires every 3 linear feet to a #14 track buss. But I wouldn’t recommend using #22 stranded with IDC’s because the wires tend to spread when compressing the IDC spade which can cause a weak connection.

Just be sure to compress the IDC spade fully with your pliers and then give the #22 a stiff ‘tug’ test before closing the IDC cover. I messed up the first couple of IDC’s attempted because the plier jaws didn’t stay aligned 90 degrees to the end of the IDC while making sure the #22 wire was fully inserted which caused the compression spade to shift and crushing the plastic housing when I squeezed the pliers.

Like most things, if you do things right during the process the results will be right…

I avoided suitcases. What’s do is: strip feeder wire 1" from end with stripper. Cut insulation of the bus wire (as if stripping, but only make the cut gesture not the remove gesture) in two places and then slice away with a hobby knife. You will have a nice bare bus wire. Just wrap the feeder around this bare wire. The connection will be pretty solid. Lateron when you come around to it, solder. But not soldering works quite well.

From my own experience I can say that I have mixed thoughts about suitcase connectors. [:^)] When installed correctly they work well. Why wouldn’t they? However I have found that I did not always pay attention to what I was doing as the process was fast compared to soldering joints. MR has a good video on how to use them correctly. I believe even more importantly that it is imperative to check every connection one at a time.

Thanks for all the advice guys. I will probably go ahead and skip the IDC’s and just make a physical connection between the feeders and the bus by splicing them together just to be certain. Seems like it’s the most reliable option given the #24 feeder wire I have to work with.

the more you strip and solder wire connections, the better and faster you will become at doing it. then the need for the alternative methods will lessen.

be happy in your work,

charlie

My new build is #905 IDC’s on 14 AWG bus and 18 AWG feeders with a 3 inch piece of 22 AWG soldered to the 18 for soldering to the track. The18 and 22 ga is solid wire. My wiring is done and not one glitch with the IDC’s and also the speed of this method really helps. I make my feeders (18 to 22 ga soldering) at the bench ahead of time knowing aprox length then trim and attach to the bus with the #905 IDC’s Doug

I don’t doubt your experience, but would note that YMMV.

If using the proper 3M IDCs for the wiring used and proper installation procedures, IDCs are reliable. If no-name IDCs are squeezed on in haste over a wide range of wire sizes outside the specified ones, they can be maddening.

So my take would be to either use IDCs properly or solder away. It’s really more about personal preference in model railroading applications.

I use 3M’s, and only 3M’s.

Funny thing is they have been on both of my boat trailers for years, never a problem.

You get what you pay for.

You would be amazed how much vibration happens around supposedly solid, immovable layouts!

As for suitcase connectors, why spend $ for those silly things when you can get the same results now (and better results in the long run) with solder? Or is your time so valuable that expense is no object? (My own layout has, literally, thousands of connections. If I used these things could end up spending more on wire connections than I have on rail.)

This is the second thread in a week on suitcase connectors. I still define them as trash can filler.

Chuck (Ex USAF flight line tech modeling Central Japan in September, 1964)

Because I have difficulty soldering overhead, and I have difficulty getting under the layout to solder.

So do what I do. Route all your electricals along the layout edge, just inside the fascia line. When wiring, the only thing that goes under the layout is a straightened wire coathanger - perfect hook for bringing vertical wires out to the aisle, where I connect them to whatever they need to connect to. All done while sitting comfortably on a repurposed kitchen chair.

I absolutely detest spelunking under the benchwork, so I designed to make it unnecessary.

Chuck (Modeling Central Japan in September, 1964 - with bulletproof, accessible electricals)

As an electrician I hate them… They are destined to fail and they will over time… In an area of high humidity they will start to rust (electrolisis with addition of voltage)over time which will start intermittent troubles which are the most fun and time consuming type to find… Go for wire wrap, solder and cover with heat shrink if you want extended life…

Chevy vs Ford argument, have used them for decades. No problems…ever.

I would like to see a picture of your layout Chuck, been hearing about it for years, I’m intrigued.