battery fuse

[mattsmith]

I am finishing the electrical and wiring on my 8A (finally) and have a concern about the #2 cable running from the battery to the starter solenoid being unprotected. I chose the rear mounting position for the battery and have a PC 680 and am wondering what the rite amperage fuse ratting would be to protect the #2 cable from the battery. I will be cranking an IO 360 with a Sky Tech 149LS. Anyone have a fuse on the battery to protect this wire?


This is the fuse I am thinking of using.


http://www.goodboatgear.com/detail/1...FdSLPAodOjkAyw

[chaskuss]

Matt,
Check out the thread linked below.

http://www.vansairforce.com/communit...t=battery+fuse

Charlie

[cfiidon]

Matt,

Generally in our aircraft we don't fuse the starter feed as it is a "momentary" circuit (See Aeroelectric Connection). Number 2 cable has a rating of 181 amps, and AC 43 recommends a 100 amp fuse for #2 in a bundle (not the case for a starter feed). I doubt 100 amps is big enough.

You can protect the circuit if you want, but in my opinion it's not necessary. I doubt any battery starter combination can draw enough power long enough to melt the #2 wire, and the other scenario would be a worn through shorted #2 cable to ground. How long will you hold that starter button in when nothing is happening?

But anything could happen. You could have a starter contactor fused and continually supplying power to the starter feed that is shorted to ground ... until it acts like a fuse itself... or you reach over and turn the master off.

Having said all that, build it the way that makes you happy. You can probably make the terminal mounts and fuse size work for you. Carry a spare.

Don