theksmith 4,148 Posted April 8, 2016 as i am setting up the accessory wiring in my Jeep, i need a clean way to wire in a couple of higher current fuses. i wasn't sure even which type of fuse would be best for this - ANL, AMG, MAXI, MEGA, etc. the attached "Quick Guide to Fuses" PDF from Blue Sea was helpful as it shows actual photos and specifies what range of current ratings are available in each format. Attached PDF: Quick_Guide_to_Blue_Sea_Systems_Fuses_and_Fuse_Holders.pdf i chose to go with MIDI fuses since they come in a wide range of amperages and are relatively compact. i needed 2 large fuse positions. one for the main feed to a Cooper Bussmann weatherproof relay/fuse box (pre-wired from forum vendor PMA4x4...), and one for an eventual hard-mount compressor system. i can foresee the possibility of needing another at some point, so i went with an expandable fuse holder setup from Cooper Bussmann, their LMI1 series. i needed an input module (LMI1-E-2-1), 2 fuse modules (LMI1-E-2-0), and a 3 position bus bar (B109-7046-3) - here you can see the same products configured for 4 positions: i purchased all of these modules from https://www.waytekwire.com, along with a some 80Amp slow-blow MIDI fuses (0498080.M). due to minimum order quantity, i had to get 2 of everything except the fuses which required 10 - even still, the total was only about $35. if i ever need to add another position, i can just purchase an additional fuse module to snap on to the chain, and a longer bus bar. i'll update this thread with some photos once i have everything wired up. Share this post Link to post Share on other sites
ob1jeeper 564 Posted April 9, 2016 Looks like a good direction K... Certianly less $$$'s than the commercially available set ups like the Spod, etc... Share this post Link to post Share on other sites
theksmith 4,148 Posted April 9, 2016 Looks like a good direction K... Certianly less $$$'s than the commercially available set ups like the Spod, etc... thanks! yes the SPOD and similar units from Painless Performance are pretty expensive. to make a nice setup yourself can still easily cost 1/2 to 2/3rds of what those go for (once you buy a fuse/relay box and populate it, get quality switches, wires, sheathing, connectors, etc.). so i do see value in those ready-made systems, especially for people that aren't comfortable with electronics. Share this post Link to post Share on other sites
theksmith 4,148 Posted April 9, 2016 i should clarify that the Bussman fuse/relay box i'm getting from PMA4x4 (http://pma4x4.com/product/relay-box/) usually includes a fusible link on the main feed... so you wouldn't really need an additional large fuse holder like i'm putting in just for that. however, i requested Rob make mine without that link since i wanted the MIDI fuse setup instead. in theory, if you correctly size all the fuses inside the Bussmann fuse/relay box then you should never melt that main link. i can see myself running right at the edge of the 80A rating on the box though, so i if i were to switch on every circuit at once on a hot day... Share this post Link to post Share on other sites
theksmith 4,148 Posted April 20, 2016 as promised, some photos of those LMI1 fuse holders: more details coming in Part 2 of my JK wiring/accessories articles... Share this post Link to post Share on other sites
91AzXJ 2 Posted April 21, 2016 Very clean job as always. Share this post Link to post Share on other sites
sjkimmel99 2 Posted April 25, 2016 Coolio. So the bus bar is powered by the one on the right and the two on the left are fused off of that? Share this post Link to post Share on other sites
theksmith 4,148 Posted April 25, 2016 Coolio. So the bus bar is powered by the one on the right and the two on the left are fused off of that? exactly! you can buy whatever bus bar you need - up to 7 positions i think total (so 6 fuses). for a large number you are supposed to run the supply module in the middle so that you have the least distance on the bus to each fuse. Share this post Link to post Share on other sites
JeepUniq 8 Posted June 15, 2016 Kris, for your Bussmann main power, do you intend to use a circuit breaker in addition to the fuse? If not, what made you decide to use the fuse instead of the circuit breaker (such as the Bussmann CB285-80)? Share this post Link to post Share on other sites
theksmith 4,148 Posted June 15, 2016 Kris, for your Bussmann main power, do you intend to use a circuit breaker in addition to the fuse? If not, what made you decide to use the fuse instead of the circuit breaker (such as the Bussmann CB285-80)? FYI, the fuse protecting the main power lead to the bussmann waterproof enclosure is really only there if a short were to occur between the battery and that waterproof box (since every circuit after the box has it's own fuse within there). as far as why fuses instead of breakers: - cost: quality high amperage breakers are a little more expensive than the fuses and holders (not a big concern though) - availability/range: i selected the MIDI format of fuse because i can get a wide range of amperages for any future circuit needs. high current breakers (over 150A) are somewhat hard to find from quality manufacturers. on my WJ i used a couple of 300A breakers from a cheaper car audio brand and was always worried they might fail so i carried a spare. - size: more importantly, i can put about 1.5 to 2 times as many fuses with nice holders in the same area as 1 high amp bussmann breaker - flexibility: the biggest benefit for me is that i can make changes easily... - i can swap out a fuse for one with a higher or lower amp rating if needed (within the limits of the wiring still). for example, i'm planning to run one compressor at first but have used large enough wiring to eventually run duals, so i can fuse appropriately for either configuration. - with the holders i used, i can easily add several more fused circuits cleanly and cheaply by just clipping more holders in and buying a longer connecting bar - it acts as a power distribution bus as well as holding fuses. Share this post Link to post Share on other sites
