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Discussion Starter · #1 ·
On a project I'm working on for the last few weeks I've had to tie in some Telco photoelectric tru-beam sensors into a control panel. Terminal blocks are push-in style which is great for stiffer, larger wires but suck for any fine strand.

The emitter probe has 2 wires that are 22awg-ish fine strand. The receiver has one wire of the same size and a sheild made from the finest wire you can imagine.

Bicycle tire Automotive tire Finger Bicycle part Motor vehicle


Even twisted together the fine strands still catch and snag on everything. I wanted to cover the shield so I used some small shrink from my labeller.

Cable label and shield shrink nested before shrinking:

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The wires are tiny!

Automotive tire Hood Finger Thumb Wrist


I think the final product came out ok....

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...but it's piddly, painstaking work. Anybody else work with this stuff? Any tips or tricks you want to share that might make it easier?
 

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I've used ferrules before. Yeah they are tedious, but once you get the hang of 'em the time gets better. One client I was at spec'd them on anything smaller than 14's if I remember right.

The odd time I've needed them and didn't have any, I've stripped the insulation longer, then twisted it, and folded it back on itself for a couple of twists. Haven't had any issues, but also depends on the type of terminals. The push-in ones could be a PITA.
 

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I have not worked much on push-in terminals but I work with tiny wires like this all the time. Using a ferrule would be the best thing to do, but if you depress the release thing, you can get fine wires in place. You have to tug test them carefully though, you can't see if they went in the right spot.

Doubling it over and twisting like @glen1971 said is a good way to build it up if you don't have ferrules but I'd still depress the release thing, you don't know if it's folding up in there or what.

I can't buy ferrules locally but I can buy small butt splices, you can usually improvise and use those as ferrules, you might remove the insulation, or half the insulation, or whatever.

I have never done this in this exact situation but sometimes you can add a bit of wire to build things up, like a western union type splice. For this you could take an inch of say #16 stranded, strip it, twist them together, and melt on an inch of heat shrink, which will cover the end of the #16. You could tin that with solder to make it better, but I don't think it would be necessary, and I thought some terminal blocks say no tinning / no solder somewhere. Or maybe that was lever nuts.

If nobody will squawk about it you could put in five 2-wire lever nuts on a carrier and transition to bigger wires. But I guess if you wanted to do that you could just splice on a bigger bit any way you want to splice it on. You could use a gray or blue small wire nut to add a 2" tail. It's pretty hack but once the door is closed your feelings of shame will start to dissipate.

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Discussion Starter · #6 ·
I can't buy ferrules locally but I can buy small butt splices, you can usually improvise and use those as ferrules, you might remove the insulation, or half the insulation, or whatever.
This is the kit I have:


I bought it about 5 years ago for just about exactly half that price. :rolleyes: I see some retailers are much higher still.

Anyway, it's a great kit to have on hand, covers the range from #10 down to itty bitty teenie weenie.

It's not the ferrules I don't like, it's the tiny wires. Reading glasses help.....
 

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Discussion Starter · #9 ·
Here's a better pic of the terminal blocks in the panel (built by others):

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I like the comb for securing the wires before they hit the terminal blocks.

I don't like the amount of room they've left to work with in the bottom of the panel. Those are 3C/#12 teck for reference. The 2 cables tied to the blocks are 2C/#14. The holes in the shadow below the numbers are for grounds. The button to release the jaws in the ground block are above the holes, can't hardly see them . Really ignorant to get a small screw driver in there to hit the button, especially once the wire bundle gets bigger.

This panel would have been a dream to work with if it had a couple more inches if room to work with at the bottom.

I'll get more pics on Monday.
 

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View attachment 166508

I like the comb for securing the wires before they hit the terminal blocks.

I don't like the amount of room they've left to work with in the bottom of the panel.
I like the combs also, never saw them.

As for the room at the bottom, I am guilty of that on the last one I built. But it will not happen on the next one.
 

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Discussion Starter · #11 ·
I'll get more pics on Monday.
One of the two boiler control panels:
Shelving Automotive design Computer hardware Electronic component Electrical wiring


Boiler sequencing control, this takes the RTDs from the buffer tank and outdoor air sensors and determines what boiler will run, or both, depending on the heating load:

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Overall view of the control panel area:

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Panels and boilers:

Industry Engineering Factory Gas Machine


A little cramped for a brand new school......
 
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