12v Wiring Safety Question

[DD716TED]

I am installing a new electric tongue jack on my trailer. The previous jack utilized a 25 amp inline fuse in waterproof holder just where the power cable exited the battery box. The new unit says to use the 30A circuit breaker that came with it in the power line but this CB is not waterproof and is a panel mount. QUESTION.. Is it safe to mount this CB on the inside vertical side of the battery box with the reset button through the side of the box for external reset if needed. I was concerned with the battery charging fumes that might be found within the battery box. Other alternative is just to use a 30A fuse where the previous 25A fuse was...

[Chris_Bryant]

It's not the corrosive fumes that are the issue, it is the hydrogen off gassing, and the fact that the circuit breaker will spark when it trips.
That said- the fumes are certainly a longevity issue.

[BFL13]

All you need is a doggy bag over the new 30a CB to keep it out of the weather.

I see that DD 716 was "Wiltsie"

[wa8yxm]

Small project box or other plastic box.. With sealed cover,,Drill, Some goop.

Drill two holes in the ends of the box to insert the wires, Connect to breaker, Make sure lid closes and seals,, Then use GOOP to secure the breaker inside the box and to seal the wire holes. Leave open for 72 rainless hours, then close box, Job done.

Or use a water proof outdoor J-Box. on this type of plastic outdoor box (Which is big enough to bolt to something) you can bolt it to the battery box (Seal the bolt holes with GOOP. run the wires down inside from top and bottom (Battery top) and seal those openings with a bit of foam or paper to block the botom half of the hole then fill with goop (I like Goop by the way) wait 2 or 3 or more days for goop to fully cure and apply cover. leave breaker inside. If breaker trips, remove cover to reset. you might add an indicator light (LED) across the breaker,, On the LED red lead goes to the battery Positive side of breaker, Black to jack side of breaker, Seal hole with goop

(The led's I use are a plastic tube with a metal ring and lense on one end wires on the other.. you apply a bit of GOOP to the tube, shove it in the hole, slip a Speed Nut (Metal spring thing) over the wire end and slide it up to the box wall.. "Tripped breaker" indicator.

[ScottG]

To answer your question, yes, the breaker would be exposed to corrosive fumes inside the battery box.
Whether or not it's enough to damage it I don't know. I would use the red battery post protectant on it to give it every chance.
Even if it does corrode, they're cheap to replace.

[Chris_Bryant]

Those circuit breakers should not be used in a battery compartment, unless they are sealed (most are not). Use the fuse holder.

[time2roll]

Just use existing. Carry a couple spare 30 amp fuses.

[beemerphile1]

The breaker only prevents you chasing a fuse at an inopportune time. You can reuse the fuse holder if you want, just put in a 30 amp fuse.

[Horizon170]

You ay want to replace the existing 25 amp with this.
clicky
OR you may be able to put a cover ove the replacement and mount it to the outside. Mount so you have to reach under the open bottom to reset, although this is a fine spot for a wasp to build a nest.