In line fuses?

[dotchess]

Ok so I am going to connect all my little 12v led lights(I think there are 7 of them to a 14 gauge wire. They will all be run on about 12 feet of wire. Then I will run all the negatives on a black 14 gauge wire.

Do I need to run a inline fuse? If so how big a fuse and do I want to put it between the lights and the toggle switch?

 

[John Wasmuth]

Never a bad idea to run an inline fuse on any lighting system. I always run 20 amp fuses but some stay with 15's.

 

[dieselfixer]

The advice from John is right on. You want to put the fuse between the power source and the toggle switch always keep your fuses as close to the power source as possible.

 

[fool4fish1226]

+2 15 or 20 amp should be fine - I like the 15amp

 

[PSG-1]

For marine use, I like these:

 

[Bob Landry]

Both wire and fuse should be sized according to the amount of current that will be drawn through the wire. Just selecting an arbitrary rating can get you in trouble if you install a 20A fuse and the wire is not rated to draw that much. I can go back and look, but I think ABYC requires a wire not in a protective sheath be fused within 7" of the power source. If the wire is in a sheath, that distance increases to 14". You don't want the fuse to be oversized. if the device develops a short, you want the fuse to blow as soon as possible. I'll look this up and if this is incorrect, I'll edit this post to show the correct info. The fuse is intended to protect the wire, not the device.

 

[dotchess]

My Led lights or pulling .036 amps each. I am running 6 of them. I am running 14 gauge wire and have decided on the marine fuse box with the ground bar built in. I am running 10 amp fuses on the lights and 20 amp fuses on the 12v lines for my million power hand held spotlights that will plug into these cig lighter adapters.
Does this sound OK?

So you are telling me to run the fuse box between the toggle and the battery?
Or should I run it between the accessories and the toggle?

Also how far from the battery should I set this fuse box?

 

[JMichael]

The closer your fuse is to your power source the better. If you installed the fuse after the toggle and the wire shorted to ground between the battery and toggle, something's going to fry and could possibly even catch fire. If the 6 lights are all you are running on that circuit, I wouldn't run anything larger than a 5 amp fuse.

 

[Bob Landry]

Dotchess,

#14 wire will be adequate for your LED lights. Fuse them for 5A and you will be fine. I don't know what your spotlight draws, but since they plug into a lighter plug and those are usually rated for 10A, I'll use that number. I'm going to guess that you will have a short wire run to the lighter plug, so you will probably be fine with #12 wire for that one. I would fue it for 10A, since that is what the plugs are rated for.

Since you are using a fuse box, it should be located as close to the battery as possible. The more wire between the battery and the fuse, the more wire that is left unprotected. Put every DC device on it's own dedicated fuse. here's a link to West Marine's chart for determining wire sizes for various applications. It states this, but I will also, use AWG wire, not SAE. SAE wire is smaller and carries less current for a given size. Also, be sure to figure it on the complete wire length, pos and neg, because current goes to the device, but also has to flow back to the battery.

https://www.westmarine.com/webapp/wcs/stores/servlet/WestAdvisorView?langId=-1&storeId=11151&catalogId=10001&page=Marine-Wire

 

[lckstckn2smknbrls]

I have one fuse for the whole system in the battery box and a fuse after each switch.