Humminbird Side Imaging Forums
General => General Discussion => Topic started by: Biggz53 on February 26, 2016, 08:53:20 AM
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Hi Everyone,
New to the forum and just picked up the Helix 5 SI unit for my jon boat. I used to run a 570 DI portable unit. Since I am using my jon boat Im converting the portable casing and mount to fit the helix unit.
The 570 portable unit came with a small 12v battery and the power cord was already wired with alligator clips for the battery with no fuse. For the sake of convenience would it be alright to just use that power cord on the new unit? The installation says to add in an amp. Why would humminbird sell a unit that is set up without a fuse if thats part of installation? Im just wondering everyones take on it and if it is a suitable switch.
thanks folks
bob
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I always feel it's better to add a fuse to a circuit. It's cheap insurance and I'll feel better if there's a short and all I have to replace is the fuse.
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I would have to think that because your 570 only draws I believe around 370 ma. which is only a little over a third amp that external fuses would not be practical. Since the Helix draws 650 ma. This makes external blade fuses readily available. My Onix 10 requires a 5 amp fuse to protect it. Also because units that are designed to be mounted in boats usually circuits that are already fused. As mentioned it is always a good idea to make sure that you have a power source that is properly fused. A fuse is a lot cheaper that a unit replacement. Today's electronics is very susceptible to power surges. Fuses can protect our expensive toys.
Phil
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I'm pretty sure the fuse is normally there to protect the battery and wiring more than it is to protect the unit. That is also the reason the fuse is place as close to the battery as practical.......You don't want to blow up the battery or melt the wires if you get a short somewhere.
The fuse needs to be sized so the maximum amp draw from the unit doesn't blow the fuse.
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Bob is correct as to why the fuse is located as close to the battery as possible. When you are connected to a large capacity battery their is a great deal of current potential. If you should develop a shorted condition a distance from the battery and not have the circuit fused properly you can have a fire that burns your boat. If the circuit is fused properly, the blows before any damage can occur. Sensitive electronics equipment is also susceptible to high voltage power surges. A good piece of equipment does have power surge protection however a properly fused circuit can also prevent serious damage.
Phil