So to clarify, you are saying the fuse is sized for the maximum current the wire can handle? The load on the circuit should therefore not exceed 80% of the wires maximum allowable load.
I typically put a fuse on a line (as in on my RTMR) that is just big enough to handle the load.
So for the upfitters, you are saying stay below 80% of their rating?
So to clarify, you are saying the fuse is sized for the maximum current the wire can handle? The load on the circuit should therefore not exceed 80% of the wires maximum allowable load.
I typically put a fuse on a line (as in on my RTMR) that is just big enough to handle the load.
So for the upfitters, you are saying stay below 80% of their rating?
correct. just because the fuse is 10amp doesnt mean you should get as close to 10amps as possible. when adding equipment, the fuse and wire should always be substantially greater than what its powering. lets take a 40" lightbar for instance. (generalizing here) they take roughly 18amps of current. i wont use a 20amp fuse for its power. i will put a 30 amp fuse for the main power and use 14ga wire depending on the distance. i run that to a relay and use whatever aux switch i choose. the bigger the fuse and wire, the less heat generated. now lets imagine i have 3 of these 40" lightbars and i use 20amp fuses and 16ga wire. all 3 of wires are all ran together. well now you have smaller wire that technically can handle the current individually, but the 3 wires in a bundle will generate more heat than a single wire. so 3 wires, close to their max amperage handling, taped together, insulated with wire loom, and ran 12ft. and lets say these were on for 2 hours (as per the op update) this will definitely cause issues with heat and possibly melt together, however may not blow a fuse, which is what most likely happened to the op. every sensitive electronic will have a fuse in/on it. look at a radar detector. it has a 2 or 3 amp fuse, yet i will run a 10 amp fuse from the source of power. this is to protect the line. nothing more. if you look at an amplifier for your stereo, both of mine have three 40amp fuses, yet i run a 300amp fuse at the battery with 1/0ga wire. having the proper gauge wire and fuse is the most important thing you can do. (other than wire it correctly). the higher amperage fuse and bigger wire at the source power ensures enough current can pass and not generate heat. the fuse on the product is there to protect the product
