Fused Distrobution Block
In the Opus Wiring FAQ it says to use a fused distrobution block to power aftermarket amps and the opus PSU. I have an Opus 150w and my question is where to find a distrobution block small enough to take the Opus power wire which is 14awg. the smallest I can find is a 8 guage out. Can I just throw somehting smaller into it like 10 guage and then connect the 10 guage to the 14 awg of the opus or what? I'm sorry for such a noob question I just don't want to mess up the psu. Thanks...
Larger gauge wire does not cause damage, but smaller gauge wire can.
Just be sure to fuse the wire appropriately for the device at the end of it since you're using a larger wire. Meaning if the opus calls for a 10A fuse, put a 10A fuse on the wire.
There are smarter commercial options than this one I made up from a fuse block that is designed to hold 6 x blade fuses.
I simply bent all of the tags on one side over and soldered on one end of a Maxi fuse holder. Smothered it all in Silicon and some conduit. The other end is bolted to the battery temrinal with a lug.
My Opus has a 20 amp fuse, so I power it from this block via another 20 amp fuse.
One thing that is confusing about the PSU's is that the wire gauge is fairly small. That makes you think that you can extend the wiring at the same gauge for a distance without an issue. NOT TRUE. Wire has internal resistance over a distance. This resistance generates heat. The solution is to use lower gauge (i.e. fatter) wire, which has less resistance.
Originally Posted by Joeybad
So, the answer to your question is: You are correct. Run the larger gauge wire from the distro block to the Opus inputs and (for best results) solder them to the larger gauge wire. Alternatively, crimp them.
Ultimately, you should use a power calculator and figure out what the right gauge wire is (check the FAQs in the nav bar above for some links). As a rule of thumb, I'd use at the least an 8 gauge wire. If your setup requires much power, go larger. You can never go wrong by going larger.
OK thanks for the clarification. I already have a 4 guage wire running into my trunk for my amp. I'll just grab a fused distro block to convert that into 2 8 guage wires one to the opus and the other to my amp. I'll just solder the opus wire and the 8 guage together then use some of that heat shrinking material to cover the exposed woring. This should work correct or will I need another fuse where the 8 guage and the 14 guage of the opus are connected?
Also for running the ign wire of the opus I'll use 10 guage to the ignition fuse in my fuse box. will this also work since the amount of power that runs through that wire isn't very much and the voltage drop over that distance (aprox. 15ft.) won't matter?
10 gauge wire is slightly overkill, but as bugbyte said, you can never go wrong by going larger.
Originally Posted by Joeybad
And you do not need to re-fuse when you go from 8 to 14, as long as the fuse at the distribution block (where the 8 hooks in) is lower than the rating for the 14 gauge wire.
Thanks again for clearing all that up. Just orded my fused distribution block and a non fused block for grounding. Will update in the worklogs as soon as I begin my install.
You don't have to use the wires that came with the opus either. When I bought my M2-ATX I realized the same thing, and rather than go through all that trouble, I simply went to Canadian Tire (woo Canada), got some female disconnects, and made 8-gauge power wires for my power supply. Saves me the ugliness of having to solder a large wire to a small one, might as well just keep it large...
Go big or go home.