Wiring LEDs

[mboyatt]

I would appreciate some advice on wiring LEDs up under the Gunnels of my 192 Tournament. I have searched online, but can't find the answer to my questions. I plan on wiring them to my accessory switch at the helm. The Grady manual for my year (1994) states that the accessory switch breaker is rated for 10 amps. My question is this, don't I have to have a fuse or breaker with fewer amps? The total draw for all LEDs will be under 3 amps. Now, I have a new Blue Seas fuse block, but I am not sure how I would wire the lEDs Into the fuse block and also tie it into the accessory switch. Is this even possible? Or could I have an inline fuse under the dash BEFORE the hot wire connects to the switch? My second question is sourcing marine gauge wire that is thinner than 20 gauge. The LED wires appear to be pretty thin/small. I can only seem to find 18 gauge and thicker. Any advice would be appreciated. Thanks!

 

[seasick]

You need to size for the max draw in amps and the total wire run length. The length includes out and back or effectively twice the physical run. 20 g is way too small and would pose a fire hazzard. For up to 10 feet run at 10 amps, 16 gauge is correct. Fro 10 to 30 feet total run, you need 14 gauge. Note that these wire sizes are for non-critical loads such as lighting. Electronics require larger gauge wire ti insure the voltage drop is 3% or less. If you changed the breaker to a lower value you could use a smaller guage but I would not recommend taking that route.
Make sure you do two things: Use marine wire and use crimp connectors.
Good luck

 

[fishbust]

Good to go with the 18 and inline fuse.

 

[seasick]

At 5 amps and 30 feet total run (out and back), sizing for 10% drop calls for 18 gauge. Just remember that if you want to add another load to that circuit, you don't have much spare capacity. And yes as mentioned, you will need to fuse at the panel for 5 amps. If you use 16 gauge, you can use a 10A breaker and have less voltage drop just incase you decide later to add something else to the circuit.
If you total run is greater than 30 feet, you have to move up to 16 gauge (for 5 amp load)

 

[mboyatt]

Many thanks for the replies and input. This has been very helpful. I have no more than a 30 foot run total, so I will go with the 18 gauge wire and 5 amp fuse. Is there any way to run the lights into my Blue Seas fuse panel for power and grounding, then have it splice off to the accessory switch to turn the lights on and off? Not sure whether this is possible, since the accessory switch has power now (switch light comes on when you hit the switch).

 

[DennisG01]

If your ACC switch is already powered, you can simply run your + line for the lights from there. Just adjust the fuse for the lighter gauge wiring you're using (assuming the ACC has no other circuits currently on it), since the ACC switch will have larger gauge feeding it.

 

[mboyatt]

Got it. Thanks DennisG and others! Greatly appreciate the help.

 

[DennisG01]

Throw a couple pics up when you're done!

 

[mboyatt]

Will do. Been doing lots of little projects on her this winter. She got a new Blue Seas fuse panel, repainted the SeaStar helm that was totally shot, had the Evinrude cowling and lower cowling skirts painted at a body shop, and am now doing new Lowrance electronics.