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I have a robot using the following screw terminal :

screw terminal

On the input side 2x 8 awg wires coming from the battery, on the other side 2 x 3 wires for 2 motor drivers and 1 step-down that power a single board computer.

There should be like 45A as peak here, and I would like to improve safety on that.

So what "professional" solution exists and which one are usually used to achieve the same thing in consumer products ?

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  • \$\begingroup\$ What safety concern with the current setup you have and what part of that do you want to have improved? I use these screw terminals for things with mains voltage just fine... \$\endgroup\$
    – PlasmaHH
    May 10, 2016 at 8:27
  • \$\begingroup\$ Well 2 days ago I had one wire not connected properly in a screw terminal, it touched another wire and I got a short that made a board burn. So I want to find safer mecanism than this, for now I have only seen Wago connectors, but I am not sure that it is what I'm looking for. The difficult part is to find a connector that allow parallel connections (1 input => 3 parallel outputs). \$\endgroup\$
    – LiohAu
    May 10, 2016 at 8:46
  • \$\begingroup\$ The problem is not with the screw terminal its the multiple connections on the distribution side that often means one of the wires is not secured. Perhaps using something like a scotchlock to reduce three wires to one or possibly use a non insulated crimp with heat shrink sleeving. \$\endgroup\$ May 10, 2016 at 9:21
  • \$\begingroup\$ "non insulated crimp with heat shrink sleeving" that looks like DIY stuff, no? \$\endgroup\$
    – LiohAu
    May 10, 2016 at 10:20
  • \$\begingroup\$ And yours doesn't look DIY? What you're looking for is called - among other things - a crimp splice, and to find the right one you'll need to determine the cross-sectional area of the wire on both sides of the splice, and select one that'll accommodate the#8 on the one side and the other three on the other side. They're available both insulated and uninsulated, and to do a proper job you'll need a crimping tool. A good one is pricey, but well worth the investment if you want to not lose any sleep with stuff in the field. Google "crimp splice" for a zillion hits. \$\endgroup\$
    – EM Fields
    May 10, 2016 at 11:30

1 Answer 1

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In consumer products, this is achieved with wire-to-wire connectors. You usually buy the connector housing and the contacts separately, and the contacts needs to be crimped to the wire. You can crimp several wires to the same contact to achieve the fan-out you need (to achieve parallel connection, as you call it). Just look at the power supply distribution inside a PC, that's how it is made (with the "molex Y cables"). Take all the wires that should go together, twist them, and crimp them in the same contact. Note that you must always be careful about the min/max AWG size specs of the contact.

Here are a few links to different manufacturers. There is a lot of choice, but for currents such as 45A, there is not many models left actually. You can use multiple pins in parallel to share the current, however.

You can find much more with Google.

Note that you usually need to buy specific tools for crimping the contacts (you can do it with pliers, but then, safety - which seems important to you - will not be guaranteed). But crimping tools cost an arm and a leg. For a DIY project, I'm not sure it is worth it. If I were you, I'd actually just use some heat shrink sleeving around the terminal, after making sure it is very tightly screwed.

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  • \$\begingroup\$ Looks like the answer I was looking for, I'll try to look at this to confirm as soon as possible. \$\endgroup\$
    – LiohAu
    May 11, 2016 at 8:20

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