if you have fuseholders on a battery or battery switch

[Lou C]

Most boats seem to have fuse holders added on to the battery or battery switch common terminal and most inboard gas boats have the battery and often the battery switch in the engine compartment. I came across this recently in figuring out my electrical issue. While you can buy a water proof fuse holder, these are not ignition protection rated (SAE J1171). However, some fuses such as those made by Bussman have the part between the 2 blades closed (other fuses leave this area open) and this gives them the SAE J1711 ignition protection rating. Just something to remember if you have a accessory wired to a battery or battery switch common terminal, in the engine compartment on gas boat....While the Bussmann fuses meet this standard, other brands of ATC fuses are open in the are between the terminals and do not meet SAE J1711. So if you use those water proof fuse holders in the engine compartment check the fuses!

 

[Lou C]

Actually doing a bit more research....the difference is that the fuses labeled ATC have the area between the terminals closed, hence the "C" in the name, whereas the ATO fuses are open between the terminals. So if you have those fuse holders in your engine compartment, do not use ATO fuses, only ATC fuses....

 

[H20Rat]

Just going to ask something dumb, but if the fuseholder is waterproof (and therefore relatively airproof), does it matter if the fuse inside of it is? Shouldn't be much for vapors entering that environment.

Completely agree if the fuseholder itself isn't sealed though.

 

[Lou C]

That is what I originally thought myself. Then I started thinking, everything else in the engine compartment on a gas inboard boat, is ignition protected. So if these fuse holders that are water proof, were tested to determine if they were sealed enough to keep out fuel vapors, it would say it meets SAE spec J1711 like starters and alternators. But they don't and only some of Blue Sea's fuse boxes come with that certification. I actually called and spoke with a Blue Seas tech guy and he said that these fuse holders are not certified as ignition protected because there is a chance that someone might put an ATO (open style) fuse in it instead of an ATC (closed style fuse). Of course they could be labeled to that effect as well, maybe they just want to sell more of the more expensive fuse boxes. In any case, he said if you use the ATC fuse it meets the letter of the law and is safe. Good enough for me.