Soldering Multiple Wires for a Distribution Joint

by rdomunky

69K12132

Intro: Soldering Multiple Wires for a Distribution Joint

Sometimes it's necessary to split power/signal from a single wire to multiple outputs. Normally I'd prefer to use a terminal/distribution block for something like this, but sometimes that's not feasible, such as when space is constrained or everything needs to be inline for a wiring harness. There actually aren't many inline connectors available for this purpose; a wire nut would do the job but isn't permanent, and there are some splice connectors like this Wago part which will accommodate up to five wires. This soldering method has worked well for me. Didn't think of the idea -- just documenting it.

STEP 1: Identify and Strip "input" Wire and "output" Bundle

In this example I have one 16AWG wire feeding five 16AWG outputs for power distribution. Bundle the output wires together with whatever temporary method works (tape, zip ties, clamps, all of the above). Try to insert the end of the input wire into the center of the bundle.

Of course, when sizing your wires you'll need to consider the total current going through your input wire. Don't expect to max out multiple output lines with a single input conductor of the same size!

STEP 2: Wrap the Entire Bundle With a Separate Strand

In this case I cut a separate length of about 80mm of my 16AWG wire and extracted a single strand. Attach the strand alongside the insulation of the input wire, and wrap it tightly around the bundle. Temporarily attach the other end to the output bundle if necessary to keep the wrap tight -- we'll cut off the excess later.

STEP 3: Solder the Joint

There are many excellent soldering guides out there, so no need to rehash that. Since there are no sensitive components nearby we can use lots of heat and a broad chisel tip (in this case I set the iron to 430C). Heat up the joint and melt the solder with the wire, not the soldering iron. You should see the solder flow between the strands through the whole bundle. Work from multiple angles and make sure to get thorough coverage.

You should not be able to pull the bundle apart once the solder has cooled.

STEP 4: Cover With Heat Shrink

Cover the entire joint with heat shrink. It can be helpful to use a 3:1 or higher shrink ratio tubing due to the size difference between the two ends of the joint.

All done! Thanks for reading.

20 Comments

baloontire3 1 year ago

Can you please let me know where I can find a soldering fixture like you use with the flexible ball and socket and alligator clips?

RyanB3200 2 years ago

Just tried this on my kayak that I wired up with a DPDT on-off-on switch. I had to solder 5 negative wires down to 1 so it wouldn't be to crowded. Worked great 👍

future-vision 6 years ago

Great job! Definitely using this for a custom wire harness. I do wonder
what effect attaching multiple wires to a single wire will have on power
throughput. If I attach 18 16awg wires to a single wire 14 awg wire
will I be able to push 12amp evenly to each? Pardon me if my terminology
is off. I'm a begginner when it comes to this stuff.

rdomunky 6 years ago

I'm assuming there's a typo in there, but 12 amps each through 18 separate wires all going into a single 14 AWG would turn that wire into a puff of smoke :-). Huge currents aside though, the way the current branches through the junction would depend on the loads on each branch. In this case it's better to think about current being "pulled" rather than "pushed". I'd use a terminal block for a split that big (https://www.digikey.com/products/en/connectors-interconnects/terminal-blocks-power-distribution/412?k=distribution%20block). Good luck!

future-vision 6 years ago

Yeah. Maybe I have it wrong. I'm basically building one of these using the exact same power supply but with an extra set of connectors. https://www.ebay.com/itm/Power-Supply-for-Antminer-L3-110V-or-Antminer-D3-L3-A741-220V/182723026931

Darkatar 6 years ago

Never thought to anchor my wires together with a strand of wire! This is going to save me a ton of headaches in the future, thanks for the write up!

72sonett3 8 years ago

> I cut a separate length of about 80mm of my 16AWG...

I know what 80 mm is and I do not know what 16AWG is... Choose one system of units, preferably metric, and stick with it.

Doodle Snackers 8 years ago

Thatth my thtory and I'm thticking to it! It pays to learn all of the different measurement units because there are many good tips and circuits with all manner of measurements. Flexibilty never hurt anyone with a natural bent for the 'bend sinister' right out of left field.

nwonharp 8 years ago

Yeah , it is a big world out there , different measurement systems , etc . We need to understand them all . And BTW , a little humor here , I guess , if someone says that something is in the " ballpark " you kind of understand that it is close enough for practical purposes . If they say it is " way out in left field " it kind of implies that it is far off from where it should be . But wait a minute , isn't LEFT FIELD part of the BALLPARK ?

Cheers , take care , and have a good day ! ....73

Callous 7 years ago

We also drive on the parkway and park on the driveway.

iskedarian 8 years ago

Interesting post, considering the effort rdomunky did in putting this instructable together. As you stated, 80mm is metric, whereas 16 AWG stands for American Wire Gauge. In this day and age, it's just as easy to look something up as it is to diss the poster. Just saying. FYI, 16 AWG= 1.29 mm dia. http://www.technick.net/public/code/cp_dpage.php?a...

Great link...

jeremytapl 8 years ago

awg means American wire gage. I'm pretty sure that's what everybody uses.

72sonett3 8 years ago

Everybody in the civilised world uses mm2 for electric wire cross section.

aquariumguy98 8 years ago

I wish I had saw this earlier. Super useful.

nwonharp 8 years ago

Good job , looks like a good reliable connection . Soldered connections covered with heat-shrink tubing works well . You didn't show the soldering iron that you used to do this . A lower wattage soldering tool may not produce enough heat to do the job properly or easily . An old fashioned soldering gun would do the job nicely and quickly . I have 4 old Weller guns ( I got them cheap at garage sale / yard sales ) of various wattages . The D550 will do 325 watts , plenty of heat for a solder joint . I would probably use 100 to 140 watts and maybe a dash of rosin flux to solder what you did , just a suggestion .

Cheers , take care , and have a good day !.......73

rdomunky 8 years ago

Good question. When I'm not using an expensive iron at a lab, I use an Aoyue 937 at home. It doesn't have the speed and consistency of, say, a nice Hakko, but it still heats up pretty fast and does have digital temp control. Don't remember what wattage it is but it will go up past 450C which is the most I've ever needed.