Blue Sea USB port install question

I am not an electrical engineer. I studied electronics for one year in college so take my advice with a grain of salt.

I run 7.5amp fuses on my USB and SAE 12v leads, for USB, Accesory or euro style.
That's small enough to protect the wiring from a short, assuming reasonably gauged wiring, but it's also big enough that I can run some high draw things like heated gear on my motorcycle or a larger fan in my rig.

It would depend on what circuit you are taping into. If you are running a dedicated circuit i:e a wire just for the USB plug then go with what was posted. If you are "tapping" into another circuit you are going to want to put a fuse between where you tap and the USB plug.

Fusing for the wire is correct advice however choosing wire the exceeds the device allows you to select a fuse that will protect both. Is this a dedicated wire fused at the Main DC distribution panel or are you splicing off an already protected circuit? If you are splicing make sure that your added current won’t exceed the fuse at the panel when combined with other loads the circuit is responsible for. USB is a small load so probably not a problem.

True but the load determines the size of the wire so... ?????

Thank you ALL

Blue Sea 1016 dual USB
calls for a 2 amp fuse on the supply line to the port.

Fuses are usually there to protect the WIRE, not the device. Any device that needs a low fuse to protect it - like a stereo - has a separate fuse built in.

As far as the USB gizmo is concerned, you could get by just fine with even a 5 amp fuse. But the REAL question is: Is that the ONLY thing on the circuit, or are there other devices that might be powered on while you are using the Blue Sea? If so, then the fuse needs to be big enough to handle the power ALL the devices are drawing at the same time.

Oops

GULFMAN wrote:
Hello All,
I installed a Blue Sea USB port in my Bigfoot Truck Camper Saturday.
I was wondering what size of fuse would be correct.
I have a 10 amp bladed fuse right know.

Thanks

Fuse for the wire, not the load. If it's connected with 18g wire 10a sounds fine.

Here is some more information
I found about this plug on Mello Mikes Truck Camper Adventure web site.
Blue Sea System
1016 Dual Usb Charger
2.1 amps
5 volts output
Parasitic draw 15 milliamps

Thanks for the reply