Figuring Proper Fuse Size

mena661 wrote:

RJsfishin wrote:
You do not need a fuse in the inverter line. Altho if you lack confidence in your installation being fool proof as far as short circuiting, then maybe "you" do.

I agree with this assessment. The inverter is only going to draw up to its rating and if your wire is enough to handle the rating then you don't need the fuse.

This is a similar argument to Randy saying a current- limited converter doesn't need a catastrophic fuse either. However, most (all?) RV's have a fuse at the battery end of the converter-battery wire.

I find it all very confusing. AFAIK the idea of the fuse is for when something goes wrong, not for normal ops.

The fuse goes close to the battery rule suggests the origin of something going wrong is at the battery end. But the inverter specs all have the fuse size related to the inverter's draw using proper gauge wire, which suggests whatever goes wrong is related to the inverter end.

A car audio store guy in town here told me the amplifier's fuse to be no more than 18" from the battery is actually a law and you can be refused insurance after a car crash with a fire, if they discover there was no fuse. The "thing going wrong" being when the battery is hit in the collision and bad electrical stuff happens.

I don't have the knowledge to sort all this out, but with all the inverter manuals saying to fuse the pos wire close to the battery, I am going to do that, and never mind what RJ says while doing his curmudgeon act :)