Help!! How to protect fish finder

Alright guys I went ahead and dropped some money on a brand new helix 9si. I haven't gotten it but in anticipation of its arrival I have been thinking a lot about the wiring and how to protect it from any and all occourances. i have a switch panel that has a fuse block in it. Is that going to be sufficient enough to protect it? I'd really hate myself if something happened to it and it could of been avoided with a 5 dollar in line fuse. I have read that you want your fuse as close to the
battery as possible but that doesn't seem like it would protect it if something were to happen say 3/4 of the way down the wire. Just my thoughts.... I'm no electrical guy. I know just enough to get myself into trouble so that's why I thought I would ask around.

The fuses are near the battery to protect the wiring not the device that faulted. When a short or fault occurs it often fries the device and blows the fuse so further damage is prevented. You can run a dedicated fused wire to the DF to make it as safe as possible, since nothing else would be on the circuit.
If its any consolation in all my years of running DF I've never had one damaged by wiring or device faults.

Definitely put a fuse as close to the battery as possible ... Adding another fuse closer the head unit is personal preference ...but it just creates more connections to lose amperage over the circuit ...

Sonar head unit should be wire direct to battery with a minimum 14 gauge ... (and I doubt seriously your boat manufacturer used 14 gauge wire) ...

Some opt for a dedicated fuse panel wired direct to the battery with 10-12 gauge wire ... and then extend 14 gauge from that dedicated fuse panel to the unit ...

This is common fuse panel used in Sonar setups ...
https://www.bluesea.com/products/502...its_with_Cover

There should still be a fuse close to the battery ...(unless you can mount the Blue Sea fuse block within 12 inches of the battery) ...

Rickie

Sorry SeaRay ... We were typing at the same time ...

Rickie

You can't protect much electronics with a fuse. Fuses are fairly slow to respond to over current. You can buy fast blow fuses, but they are also too slow to protect much. SMT devices can explode on a pcb and a fuse may or may not blow. I have witnessed some amazing explosions without fuses blowing. Fuses protect people most time.

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Originally Posted by fishbrain

Alright guys I went ahead and dropped some money on a brand new helix 9si. I haven't gotten it but in anticipation of its arrival I have been thinking a lot about the wiring and how to protect it from any and all occourances. i have a switch panel that has a fuse block in it. Is that going to be sufficient enough to protect it? I'd really hate myself if something happened to it and it could of been avoided with a 5 dollar in line fuse. I have read that you want your fuse as close to the
battery as possible but that doesn't seem like it would protect it if something were to happen say 3/4 of the way down the wire. Just my thoughts.... I'm no electrical guy. I know just enough to get myself into trouble so that's why I thought I would ask around.

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If you have an incidental short to ground on the protected side of the fuse, the fuse will blow and a high probability of no damage to your unit. Thus the closer to the battery the fuse is placed, the more wire is protected.

If you have an incidental foreign battery potential applied to the protected side of the fuse, the fuse will blow and you will have a high probability of damage to your electronics. A fuse close to the electronics would not prevent the over voltage condition.

Thanks for the advice.... With that being said what's the best way to protect my fish finder?

I run an inline fuse about halfway between the unit and the battery and its dedicated wiring direct from the battery to the unit . Don't know much but the units for sure don't like low voltage ,not sure what they handle on the upside though . It seems to me most units are pretty durable although I have seen some malfunction due to the quick disconnect being damaged taking if off and putting it on .
This said I don't remove mine unless I have to , I run from the garage to the lake with it on and only remove it in situations I think could damage it like big storms and or the possibility of theft .
A cover for the unit might be wise as well .....best of luck with the new unit , the ones some of my buds have are right nice

What Rickie said...
The only place I can think high voltage might accidentally get introduced to the unit ... in a boat... is if the motor charge voltage went wild .... a fuse at the battery would protect from that......There is going to be no way to protect anything if your boat gets struck by lightning.
I think a 3 amp fuse is recommended for the Helix 9. Use a quality spade type fuse ....The glass fuses can introduce voltage drop and intermittent problems over time.

You cannot protect the unit from itself. You can only protect the wiring to the unit. iT IS OHMS LAW.

When I mentioned "foreign potential", I was not speaking of lightning. Any voltage not associated with the specific electronics circuit would be a foreign potential, for example a 24v TM potential would b be foreign to the 12v of the Sonar circuit.

This does happen.

Humminbird recommends a 3A fuse for the Helix 9. I wired my units directly to the battery and used this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

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Originally Posted by GWDawg1

Humminbird recommends a 3A fuse for the Helix 9. I wired my units directly to the battery and used this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

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I used the same fuse block at the battery.