Double redundant fuses. ('06 GS)

When adding an electrical device to a fuseblock, the in-line fuse that comes with the device is....

1. Completely unnecessary and can be eliminated.

2. Nice to have since it adds an extra "layer" of protection

3. An absolute requirement if protecting your wiring/bike is of any importance to you.

Case in point.

I have a Centech AP-2 installed on my 2006 R1200GS and just received a Gerbing Dual Portable controller to manage my Gerbing Jacket and Gloves. I connected the controller to a 10A switched circuit on the Centech. Can I eliminate the in line fuse (also 10A) that Gerbing included? Seems to me that if I wired the unit straight into the battery, then the fuse is needed. But do I really need two 10A fuses about 6 inches apart from each other?

One fuse per circuit as close as possible to the battery. My 2 cents

IMHO, no need for two fuses, if you left them you would only be protecting about 6 inches of wire with the extra fuse. Each time you go through a connection you also increase the chance that corrosion or other problems would crop up, thus the extra fuse just adds a bit more uncertainly over the long run.

Wayne

There is no reason for two fuses in series for a simple power feed to a single accessory connected to one output of a fuse panel.

Sometimes, one might connect a couple accessories to a single fuse panel output and in such cases, a higher capacity fuse at the panel and a lower capacity oe in the line to each accessory might make sense.

If you need to pick fuse capacity, a good guideline is 1.5-2X the max power use of the circuit being protected. You don't want a 30A fuse protecting an accessory that uses only 1A. The ultimate purpose of any fuse is to prevent the circuit wiring from going up in smoke in case of a short to ground so it is important that the fuse value selected be low enough to ensure wiring does not become a fire source that destroys the machine. The wire gauge determines what power it can carry before becoming a potential fire source.

Obviously, there will always be some sort of (ideally short) runs of wire between the power and the fuse. It is equally important to make sure these runs are well located and protected against physical dmage and shorts to ground because they are not fuse protected. An example might be something like mounting a fuse panel with 30-60A total capaciity up front on a bike with a battery in the rear; in such case it makes sense to put a fuse as close as possible to the battery in the power feed to the panel so that there is no long run of unprotected wire and to ame sure the piece comingoff the battery is well protected from possible damges that could lead to ground contact.