Fuse size question

I have been running two hds12 units on a 5 amp fused line directly from the battery for several years with no problem... I recently added a 1022 garmin with livescope and started blowing fuses when I have all three units on it run two units fine ... I went to a 10 amp fuse and that seems to have solved the problem .. my question is .is a 10 amp too big I have left all three units on for several hours on full brightness with the boat on a trailer with no problem and the wire is only slightly warm with al 3 units on

Actually you should have each unit wired separately with proper fuse for each unit. Depends on how you have all this wired together. Also if you feel warmth in that wire it’s to small for the load your putting on it. Ideal thing would be to have a separate fuse panel wired to battery with 10 gage wire then each unit wired to its on separate fuse of proper size.

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Originally Posted by Cray

Actually you should have each unit wired separately with proper fuse for each unit. Depends on how you have all this wired together. Also if you feel warmth in that wire it’s to small for the load your putting on it. Ideal thing would be to have a separate fuse panel wired to battery with 10 gage wire then each unit wired to its on separate fuse of proper size.

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I do have 10 gauge wire from the battery to the bow to the hds12 and live scope and I tapped into the same 10 gauge for the hds 12 at the console. Each unit is fused and the main ten amp fuse is at the battery the only slight warmth I felt was at the 10 amp fuse at the battery not in the wire it's self... and that's with all three unit on up on full brightness.. my main question is does a 10 amp fuse sound too big for what I have even though everything seem to be working?..thanks

No it is not as long as you have fuses on each unit like you describe. That 10 amp is only protecting the wire itself from fuse to you connections. If that fuse is warm I might install a 20. Is the connector for fuse also 10 gauge?

Quote:

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Originally Posted by Cray

Actually you should have each unit wired separately with proper fuse for each unit. Depends on how you have all this wired together. Also if you feel warmth in that wire it’s to small for the load your putting on it. Ideal thing would be to have a separate fuse panel wired to battery with 10 gage wire then each unit wired to its on separate fuse of proper size.

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I wired my Echomap 93sv to the existing power wire that my old HB was using. I pulled a new 10Ga. wire from the battery to the GLS10 Livescope unit fused separately which is what Garmin installation manual suggest. Install a separate power switch for the GLS10 black box.

Quote:

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Originally Posted by Cray

No it is not as long as you have fuses on each unit like you describe. That 10 amp is only protecting the wire itself from fuse to you connections. If that fuse is warm I might install a 20. Is the connector for fuse also 10 gauge?

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The wire on the fuse is lighter gauge and is run thru the perko switch
Attachment 373044

Get a fuse with wire at least 10 gage, direct to the switch with a 30 amp fuse. Looks like you have 14 or 16 gage wire trying to supply power to your 10 gage wire. That's why the fuse and wire are getting warm.

My depth finders have a 3 amp fuse each . Trolling motor has a 50 amp .

The amperage rating of the wire depends on several factors including the gauge size. It also matters what type of wire but assuming it is stranded copper, it can handle 15 to 30 or so amps depending on the length. If it is running from the back of the boat to the front, it should still be good for at least 15 amps. The smaller gauge wire on the fuse holder can handle less amps but it is very short so assuming it is 14 gauge at least, it should be fine at the 15 amps. It sounds like you have it, but each device then needs its own fuse to protect the device, usually 3 amps and they normally come with the unit.
One thing that I added to my boat that has helped so far is a voltage conditioner/regulator near the electronics. I had one unit that was sensitive and would flip off every time I started the engine, trimmed the motor, the bilge pump came on, etc. The conditioner takes like 8 to 15 volts and gives a steady 12 volts out. I cannot see a dip in voltage at all now on the display when I crank the engine.

Robot Check

These are good to use. Amazon.com fuses with 8 gage wire.