Fuse size for Fuzeblock

[Havard]

Running a fuzeblock on the back of the bike. What size fuse should i use near the battery for the hot wire. Hooking up the garmin 660 to the fuseblock now and possibly auxilary lights down the road.

New at all this electrical stuff.

 

[worldbound4now]

What size wire are you running and what is the length of said wire gauge used to power and ground the accessory power unit?

 

[LAF]

Running a fuzeblock on the back of the bike. What size fuse should i use near the battery for the hot wire. Hooking up the garmin 660 to the fuseblock now and possibly auxilary lights down the road.

New at all this electrical stuff.

15-20 would be more than enough I would think. If the FuzeBlock is the brand name then my understanding it has a fuse and relay built in. And even if there is no fuse, every circuit you use does and you can choose what size fuse for what accessory you are going to run off it is. I ran 10 gauge wire direct to it from the battery + and - side, and the same for the switched power connection. I guess a 15-20 right under the battery panel would be ok as a prevent, and not to hard to get to for service. Or better yet put it right next to the fuzeblock in the back.

I love my FuzeBlock and down the road I am going to cram one in the front somewhere.

 

[Patriot]

from the FZ1 web site:

How Much Current Can the FZ-1 Handle?

This isn't as straight forward as you might think.

The FZ-1 has two separate current paths. One is for constant power and the other goes through the relay for switched power. Each circuit can handle up to 10A (120W). The total amperage used via the relay (switched power) should not exceed 30A (360W). The total amperage on the constant side should not exceed 30A (360W). The total amperage for the entire FZ-1 should not exceed 30A (360W).

so I have installed a 30amp fuse using a 30amp Radio Shack inline fuse holder with 10 gauge wire

30-Amp Inline Blade-Type Fuse Holder

Model: 270-1234 | Catalog #: 270-1234

$2.69

 

[Havard]

I am running 12 gauge wire to the back of the bike which is about 3.5 feet. The ground is also 12 gauge running back to the battery.

 

[ionbeam]

#12 wire has a conservative rating of 40 amps in free air (not buried in a harness bundle). This certainly exceeds the need. Usually fuses are rated for twice the expected load. If you were to run a pair of 55 watt driving lights, GPS, audio mixer and heated grips the load would be in the area of 155 watts which is roughly 11 amps at 14 volts so a 20 or 25 amp main fuse would be appropriate. Your fuse needs a bit of 'head room' because some items have an initial turn-on inrush of current that is higher than the steady state running current.

Don't sweat finding the exact fuse size, as long as the fuse is under 40 amps and over what you guess your farkles will draw you will be OK.

So, your fuse blew, was it too small or is something is wrong? Look at the fuse filament. If it was too much steady current, the filament will simply be open. If it was caused by a short or something that failed and drew too much current the fuse filament area will look black and/or burned. Too much steady state current will slowly melt the fuse filament, a short duration high current spike will vaporize the filament causing the burned look.

 

[SLK50]

Or better yet put it right next to the fuzeblock in the back.

:nono: Fuse should be as close to battery as practical to protect wiring.

 

[DeweyIsgod]

Agree with Patriot. A 25-30 amp at the battery should protect the fuzeblock itself. my devices connected to the battery have much lower fuses in the fuzeblock (5-15 amps) based on the power handling capability of the device.

 

[NMRoadRunner]

size the fuse accordinging to what you intend to power with it, such as a compressor will draw aroud 10 amps, you go with a 12amp fuse to protect the devise. Your wire sizing should be higher rated then the fuse sizing is. you are protecting the devise first, and the wiring second. Your 12 AWG wire is good for around 30 amps with a small safety factor built in, but you want to size the fuse for the devise as stated above. Add the total load on the Fuzeblock and fuse a little over that as long as it doesn't exceed the wire size loads. There perfectly clear I hope.