Industrial Fuse Holders. Cartridge fuses and 3AG fuse 5-pack boxes.

Inspiration

At work we have multiple large industrial pieces of equipment and keeping track of which spare fuses go with which piece of equipment has been a challenge. We started by putting the spare fuses in the power enclosure of each piece of equipment, but that just lead to a disorganized scattering of bags and boxes in the enclosures. So I thought of this to help organize and be able to (mostly) see at a glance what the current stock is. I was able to sell the idea to my management as a LEAN project.

Design

Cartridge-FuseHolder

I first designed these in FreeCAD 0.19, but while the source file was usable for me, I felt they were a little bit clunky for distribution. Then with the release of FreeCAD 0.20 with the added “Configuration Table” feature I completely refactored the cartridge fuse holder file to allow choosing both the fuse size and the number of fuses as drop-down selectable parameters in the Part object's data properties tab.

Here the “Fuse Count” and “Fuse Size” properties are selectable lists from the “Params” spreadsheet in the design. I included many more fuse counts (2 through 20) and sizes than I needed for my original design to help it be more useful for others.

Note, the FreeCAD file will create slightly larger objects than the attached .stl files because I discovered that for the smaller fuse sizes I didn't leave enough allowance for the chamfer. I added the chamfer size to the outer dimensions of the holders to avoid the FreeCAD issue of a chamfer intruding on another feature preventing the chamfer operation from executing.

3AG-FuseBoxHolder

The file for the fuse containers is sized for the long “standard” Eaton Bussmann fuse containers that hold five 1¼" long fuses. I measured the fuse container that I had (rounding up to the nearest mm) and designed the holder from those dimensions. As you can see from the pictures, it just happens to also fit the Mersen fuse container. I make no promises that it will be sized right for any 5-pack of 1¼" fuses, but my suspicion is because the Eaton Bussmann fuse pack has been around for so long (there are lots of people on eBay and other aftermarket marketplaces selling empty packs) and so many companies have made organizers for them, I figure that other fuse manufacturers would copy the bounding box of the Eaton Bussmann holder (Mersen certainly appears to have). 

When I first started drawing this one, I was experimenting designing it to completely use named dimensions from sketches as parametric values. While this did work, and felt clever, I decided for publication it would be more difficult for others to grock what to change to resize it for themselves. So, I added a “Params” spreadsheet with all the important dimensions and pointed the original “source” dimensions to the spreadsheet values. Simply change the values in the spreadsheet to change the size of the intended boxes this will hold. Note, however, due to the way this was designed it only holds 2 boxes. To remix to hold more boxes you would need to modify “HolderPofileSketch” to hold more than 2 boxes deep, and/or the pad (extrude) value in "HolderProfilePad" to hold more than 1 boxes wide.

Implementation

I only needed a handful of sizes. (See the .stl files.) I chose the sizes to be double the minimum quantity that we had decided for each fuse size/type/value so at a glance I can see that I would need to order more if any holder was less than half full. I would then order enough to fill the fuse holder. (As you can see in the pictures of the fuse holders deployed in the first 3 power enclosures, I did have to order some fuses…)

I printed labels on a P-Touch labeler for each holder including the fuse type, size, rating, and the locations (both the specific piece of equipment, and the fuse locations within that equipment) where they are used. Unfortunately I can't upload the .lbx file from the P-Touch design software to this repository, but the pictures and the following screenshot should be a good enough guide if anyone wants to copy or be inspired by my layout.

I printed these in HatchBox black PLA with 4 perimeters and minimum 2.1mm thick top and bottom layers on the Original Prusa MK3 that we have at work. With these setting infill really doesn't matter. I used 20% Gyroid, but I probably could have gotten away with no infill. For all the PrusaSlicer print settings that I used, see the .3mf file in the “Eaton Bussmann Fuse 5-Pack Holder” design file folder.