Wire and Fuse size

[Capt. Bob]

There's much here to be read on wire and fuse sizing and the general consensus seems to be........ big wire, little fuse.

I have placed my Blue Sea panel where the stock tool kit resides. I've run 12ga. for both power and ground from the battery, (fused 25amp at the terminal) through the relay and to the panel. From there I run back to the front with 16ga. I'm hooking up three things (for now). My V1, GPS and a volt meter. The supplied wiring harness for both the Zumo and the V1 appear very small 22/24ga (?). Both use a 2amp fuse. If I understand everything I read, there should be no problem putting the two wire sizes together from a failing (fire) standpoint. As long as I use the small fuse, I see no difference between that and how it would be wired in a car.

I'm understanding this correctly, no?

The same size (22/24ga) could also be used for the volt meter?

Thanks.

 

[2WheelTiger]

Try this.

 

[ponyfool]

Your current plan should be more than adequate.

 

[HaulinAshe]

FWIW

I'm a big fan of both fusible links at the battery post and a fuse at the load end of the wire. Fusible links purchased at discount automotive stores will usually tell you on the package what wire size is appropriate for the link.

I prefer to use:

#8 wire for 30-amp circuits

#10 for 20-amp circuits,

#12 for 15-amp circuits.

Just my preference based on runs of 6-8 feet.

 

[Capt. Bob]

Thanks gentlemen,

I appreciate the help. The calculator's pretty slick too but in the short distances we run on the bike it appears to be minimal. It also appears that the 2amp fuse used by the GPS and V1 covers the 22/24ga wire. I thought what I have would be OK but it never hurts to ask.

Thanks again.

 

[Constant Mesh]

Since the FJR has less than 150 watts of available accessory power, fusing any circuit above 15 amps is meaningless.

You can use larger wire to minimize voltage drop but using a larger fuse offers no value.

 

[DaveFJR]

The proper fuse rating is determined by what you are trying to protect. Sometimes you need more than one fuse to protect both the wiring and equipment.

If you have one 15A fuse and a short exceeds 15A draw, the fuse blows, the wire is protected, and everything on that circuit would go dead. However, if one piece of equipment is partially shorted internally but the total draw is less than 15A, the fuse would not blow and current would continue to flow. That is why some aftermarket electronics has an internal fuse or an inline fuse (rated by equipment draw, not the supply wire size.)

 

[FuzzyRider]

Since the FJR has less than 150 watts of available accessory power, fusing any circuit above 15 amps is meaningless.
You can use larger wire to minimize voltage drop but using a larger fuse offers no value.

Gen I bikes have 120-130 spare watts of power. Gen II bikes have an extra hundred watts of alternator capacity for something like 220 spare watts of power.

 

[HaulinAshe]

Since the FJR has less than 150 watts of available accessory power, fusing any circuit above 15 amps is meaningless.
You can use larger wire to minimize voltage drop but using a larger fuse offers no value.

I beg to differ. The battery has stored energy(capacity) that allows pulling current well above 15 amps for short periods like...

* when running an air pump to fix that flat.

* The first five minutes of the cold-ass ride when all of your and your passenger's heated gear is on high.

There are several situations where a brief current draw could exceed 15 amps. Obviously you don't want that condition to persist for more than a few minutes, but you can effectively wire and fuse for it.

 

[weekend rider]

I think electriciy 101 is need here some bad info has been given out

 

[HaulinAshe]

I think electriciy 101 is need here some bad info has been given out

[SIZE=14pt][/SIZE]

EIxR
How's that?

 

[Capt. Bob]

I'd say more like grammar, a Mr. Ohms?