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Wiring Power Distribution Box

  1. Apr 23, 2010 #1
    Hi all,

    I'm trying to wire an 8 way fuse box for use as a power distribution block, but I'm having trouble with wiring the power properly. See the attachment for the circuit diagram.

    As you can see, the entire V+ side is tied together. Last year we used a fuse box that already had that whole side wired together internally, but we can't find one this year. Any ideas on how I can connect all those 12 or 16 gauge wires together easily?

    Attached Files:

  2. jcsd
  3. Apr 24, 2010 #2
    Ask an electrician to help you find the right box.
  4. Apr 24, 2010 #3
    An electrician? It's for a race car, not a house o_O

    Also, we need it SOON.
  5. Apr 24, 2010 #4


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    Staff: Mentor

    In fairness, I had the same initial reaction. But I also had trouble viewing the diagram at a resolution that I could understand. Could you please try posting it at about twice that resolution?

    Is the main question how to connect multiple large wires? Would wire nuts work?
  6. Apr 24, 2010 #5


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    Science Advisor

    For similar applications, we used terminal blocks (that's a more generic term: the specific one in this case is probably barrier strip), similar to these ones, though many manufacturers make similar products:
    http://www.marathonsp.com/DoubleRow.html [Broken]

    The thought of crimping / soldering a bunch of tiny jumper wires may not be so appealing, so you should buy the little jumpers that bridge between two (and sometimes more) adjacent positions (your local electronics supplier should have them next to the blocks, if not, ask a sales guy). Properly chosen crimps will fit right on top of them. For instance:
    http://www.marathonsp.com/TBAccessories.html [Broken]

    As for fuse holders, you can get ones that look pretty close to the barrier strips I linked to above. Most of the fuse manufacturers (Littelfuse, Cooper Bussmann, etc.) will sell fuse holders that can hold multiple fuses (sometimes called fuse blocks or fuse panels), and have various types of connections, from screw-down to blade-type connection. From the same manufacturer:
    http://www.marathonsp.com/HK250Datasheets.html [Broken]

    All that said, this may be of interest to you (note the term 'common feed', and the fact that it uses fast-ons / blade connectors):

    Now, one thing you HAVEN'T mentioned, but which you should give thought to is: what type of crimp will you use (spade, spade with little prongs that stick up to ensure they don't slip out, etc., ring), and how are you going to attach your wire to it (solder, crimp, solder + crimp, etc.)?

    For the first question, there's a bit of a trade-off between how secure the connection is (meaning how likely crimps are to come loose) and how much time you want to spend undoing screws. I find the spades with the prongs raised at the end a nice compromise, but you'll have to figure that out for yourself. Of course, if you end up using the fast-ons (a.k.a. blades, quick connects, etc.) you don't have to worry about undoing anything, but they can come loose a whole lot easier than the other ones will. If you make/break a connection a lot, you may need to 're-tension' the female blade with some pliers.

    As for the second point, I find a PROPER crimp to be quick to make, strong, secure, and long-lasting. Find money to save elsewhere: spend money on a set of proper ratcheting crimpers (between ~$30-50 and $200, you probably want the lower range of the spectrum) instead of the plier-style ones. And make sure to actually follow the wire stripping / insertion instructions on the outside of the package of the crimps (and obviously, choose the right crimps for the gauge of wire you're using). I'd advise making a few test crimps on scrap wire to make sure they won't come lose, and gently tug the connections you do make (they should fail right away).

    From past experience (undergrad robotics competition) stuff invariably fails, stuff fails at competition, and you need to be the one to get it going ASAP (without it re-failing). Make sure you do a good job the first-go round, and layout the box (and wiring) neatly and possibly even more important, accessibly.

    Hope this helps!
    Last edited by a moderator: May 4, 2017
  7. Apr 24, 2010 #6
    Sure, see attached VSD file (It's the best I can do). Also: Wire nuts? *googles* Oh. No, not so much. We have crimp style attachments that would work better already.

    AH HA! Common Feed! (Common Hot, specifically!) That's the term I needed. Seems the world is brimming with common hot fuse boxes, just didn't know it :D Also, it seems "gang" is a popular term.

    I would prefer screw on terminals, but we're constrained by space, so I may need to use blade terminals from the underside style box.

    I already have a nice pair of ratcheting crimpers that I've been using, though I may have destroyed them yesterday crimping something too strong for them... They don't crimp properly now... they're too light on the crimp :(.

    This is what we have right now, but I don't know how I would jump each blade connector (on the bottom) with 10 or 12 gauge wire... It's not like I can crimp two together...
  8. Apr 25, 2010 #7


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    If that's the only thing you can use, this won't be pretty, but you can hack it somewhat. Strip some 8 or 10 gauge copper wire and bus-bar the connections you want to connect to each other. What do I mean by bus bar? Solder each of the male fast-connects to the copper wire. You could even leave some insulation on the wire and put a connector on the end of it.

    Unfortunately, you'll probably need to increase the heat on your soldering iron to get the copper (and anything else attached to it) warm enough to melt the solder onto each of the tabs, and in so doing, you may end up warping your box.
  9. Apr 25, 2010 #8
    Yea, this was pretty much the conclusion I came to as well. But what I may try to do instead is cut a slot between the parallel plastic ridges and fit a custom piece of aluminum between them. I got that idea from the last years fuse box (which I finally pulled off the car).

    And I noticed that the .VSD didn't get uploaded last time. Oops xD

    Here's the link to it if you still want to see it. Wouldn't mind comments, either:

    I remade the .pdf to a higher resolution. Actually, I think it's vector instead of raster this time...

    Attached Files:

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