I'm working on a raspberry pi project – a sump pit monitor that sends an emergency email if a float switch above the point where the water triggers the pump is switched (purely for monitoring, not driving the pump or anything, mainly peace of mind). I have a couple of float switches I'm using. The float switch wires are 24 awg and about 15 inches. I need them to be a few feet so I'm planning to buy some 24 awg wire and splice them to the switch wires. The wires are AWM 1007 – will any 24 awg wire do? This might be a dumb question but the bare wire is a silverish color. Is it safe to assume it's copper or could it actually be something else? Does it matter?
Anyways, for the splicing I bought a small pack of the yellow IDEAL UY IDC connectors for 5 bucks (the yellow ones here: https://www.homedepot.com/p/Ideal-IDC-Connector-Multi-Pack-UB-UR-UY-Standard-Package-4-Pack-of-25-85-960/302918233)
I didn't realize at the time how heavily it's recommended to use the dedicated crimping tool for these. The tool, at least that I saw at the store, was about 30 bucks. I would buy it but it seems very dedicated, and I may never need to use it again. I tested some 24awg wire I had laying around in the connector using just a pair of regular pliers, and got what appears to be a clean connection (using a multimeter continuity test).
If the splice failed it'd trigger the emergency email (the switch is normally closed, rising water opens it) which is the "safe" way to fail, and this itself isn't mission critical, and it only needs to carry a digital 3.3v signal – are regular pliers (and testing after making the splice) good enough for this application? Does anyone have experience with the splice failing later or intermittently?
Is there a solution for such small wire that doesn't need crimping? It appears nearly all wire nuts and other twist connectors that I can find only go down to 22.
Best Answer
You do NOT need the dedicated crimp tool for these splices. What you need is something that will close with the jaws parallel at the proper gap distance.
A pair of ordinary slip-joint pliers works well when you have the pliers set for the larger gap size. Add a shim of some sort if the gap is too large when the jaws are parallel. The smaller slip-joint pliers that I use have a gap that is just about bang-on. The larger slip-joint pliers are used with a small piece of 1/16" PCB material as a shim.
I actually do own the proper crimp tool for these connectors. But I rarely use it - the slip-joint pliers are usually close at hand whereas the proper crimp tool is put away in another building.
All that said: you shouldn't use these in a location where they might get wet UNLESS you have the grease-filled version. Although the grease-filled version is a standard item for telephone repair persons, I suspect that Home Depot doesn't sell them.
What I would do instead is simply twist and solder the conductors, then encase the connections with adhesive-lined heat-shrink tubing.