Fletch's 1976 170 Rebuild

[kraw2]

Hey Fletch,

Don't you have a main hot wire coming from the battery to feed the switch panel, or terminal block. I guess you went from the battery to the terminal block? That's the wire that needs a fuse.

[Fletch170]

The way it's wired now is From both batteries, to the battery switch. From there, the common goes to the motor and the main positive BUS. From the bus is the 14ga wire to the main fuse pannel. Are you saying there needs to be an inline fuse on the run fron the positive bus to the fuse/ switch pannel? If so, what amp fuse?

PS, Thank you for the help!

[kraw2]

The wire from the common on the battery switch that goes to your terminal block needs a 30 amp inline fuse within 7 inches of the battery switch.

You can see my 40 amp inlne fuse next to the bottom of the battery switch.

[kraw2]

I used #10 wire so the 40 amp fuse. My main power wire goes from the battery switch to the fuse block and then from the fuse block to the accessories.

You have a fused switch panel with #14 wire feeding it so a 30 amp inline fuse next to where it connects to the battery switch is just right.

As said before every circuit, accessory, etc. has to be fused to protect the wire and prevent a fire..!

[Fletch170]

Crap.......I was hoping to use the 2ga battery cable to connect the switch to the bus terminal.

SO, you are suggesting that I use 10ga wire from the battery switch, with a 30a inline fuse right next to the switch. From there I will run the 10 Gage right to the fuse/ switch pannel? The only thing hot wired directly to the battery would be the "Auto" position to the bilge pump?

Let me play Devil's advocate here:

Assuming I'm running 2ga battery cable to a bus terminal, what is preventing me from putting the fuse inline near the bus on the way to the switch pannel? There is no way the acessories could burn up a 2ga wire or a bus, right?

Also, the feed into the fuse pannel/ switch pannel is 14ga, and will only accept that size. So, wouldn't fusing 10ga with 14 just negate the 10 all together as that small section of 14 is still under load?

[dburr]

http://www.windsun.com/Hardware/Wire_Table.htm

This table gives you an idea of how many feet (6) of #14 wire you can run at 12vdc at a max of 15 amps and not get in trouble.  You want more then 15 amps, you gotta go to bigger wire....  If you want a 30 amp fuse as kraw2 suggests you need to step up to bigger wire.

Assuming I'm running 2ga battery cable to a bus terminal, what is preventing me from putting the fuse inline near the bus on the way to the switch pannel? There is no way the acessories could burn up a 2ga wire or a bus, right?

Battery to switch to fuse to bus...  No other safe way to do it. In the event that something bad happens you HAVE to be able to remove the power source and wire cutters ain't the best when the fire's getting hot..  I've seen more then a few burn patients and that is #1 on the list of ways I don't want to go!

The work that you've done to date is fantastic! The light is visable at the end of the tunnel now so take you time with the details and make damn sure you're not looking at the train...

[Fletch170]

ok, I think I'm going to keep it as is and put an inline ruse in 14ga right by the Bus block. Turn everything on and see how much it actually draws through the circuit. It's only going about a foot from the block to fuse pannel.

All lights are LED, and I only have a stereo, Depth finder, and a VHF. If I'm drawing close to 15 AMPS, I would be REALLY suprised.....right?

[dburr]

You are correct.. Those LEDs are next to nothing and the biggest draw should be from the sounder.  The sum of the loads will give you an idea of what to expect if everything is on and you key the mike on the VHF with it set on Hi..  Are you going to add an Aux jack for a spotlight?

[Fletch170]

Crap,  Yes, I have an AUX jack for a spotlight......I'm guessing That SOB is going to drew some serious Juice. Should I wire that puppy right to the battery Bus with some decent 10 Gague?

Damnit.....I didnt even think about that.

[Fletch170]

How much do those handheld lamps draw?

[dburr]

Google  the type of light you want and that should tell you.  Spot lights have come a long way and don't draw what they used to unless you get silly..
My aux jack is fused directly to the hot bus with a 10 amp fuse with # 14 wire..  Does not really answer the question but it works..

[Fletch170]

Sounds good. I'll do the same.

[kraw2]

Hey Fletch,

You need to be able to supply the power outlet with 20 amps even though will probably never need that many. With your setup you can use #12 wire with a 20 amp fuse to the accessory power outlet. From looking at the pics it would only be a couple of feet or less.

With all your accessories that need fused power that's why I suggested a Blue Sea fuse block. I know you already had all those terminal blocks and that's why you used them. It would so much easier and cleaner if you used a fuse block.

All you need is a red power wire into the fuse block. Then you could run a "fused" hot to each item. The grounds can come back to the ground buss you already have. You can get a Blue Sea fuse block without internal grounds. Much cheaper.

Do not run the power outlet thru a switch. Power it directly. The switch can only handle 15 amps no matter what size fuse or breaker you use.

[Fletch170]

Kraw,

I get what you are saying about the accessory jack.

However, I don't understand what you mean about the fuse block? If I have a switch pannel that is fused, what is the difference? Wouldn't that essentially put 2 fuses on the same circuit? I know you can't have too many fuses assuming they are the correct size, but I'm not sure I understand what you mean?

[kraw2]

Fletch,

Just a fuse block for the other items like your power outlet, LED lights and whatever accessories you might want to add later.