wire size

[oldkennerguy]

I am trying to repair a recurring problem in my old houseboat,and I need to replace the 12v wires,hot and ground, from my batteries to the main switch and fuse panel.What size wire should be used?

thanx

 

[DRIFTER_016]

Re: wire size

It depends on your load and added accessories.
I did this same thing on my boat last Saturday as the old wiring was under sized and coroded. I was having power issues because of this. I would say that on most boats in the 16 to 20 foot class that 10 guage would be perfect for any added accessories you might install other than high powered amps for your stereo. If you are installing a boomin' system run seperate wiring just for it.

 

[PondTunes]

Re: wire size

most are wired with 2awg you can go larger but i wouldn't recommend anything less esp to the starter.

 

[drewpster]

Re: wire size

If your battery to main switch circuit includes power to the starter and the length from the battery positive to starter and negetive back to the battery is more than ten feet I recommend 1/0 105c marine minimum. This to and from the battery.

 

[jlinder]

Re: wire size

If you search this forum you will find a lot of posts on this.

There are 2 considerations when picking wire size. The first is that it has to be large enough so it does not heat up and cause a fire.

The second is that there is always a voltage drop when you pass current through a wire. You want to make sure the voltage delivered to the equipment is still high enough.

So when you pick the wire size you first need to make sure it is big enough to not burn up, then keep the voltage drop below a certain percentage.

I can give you a basic rule of thumb for house wiring on size. 12 gauge will carry 20 amps, 14 gauge will carry 15 amps. From there you double the amperage every time you go down 4 gauges and halve it everytime you go up 4 gauges.

For example, 8 gauge is 4 less than 12 so it would carry 40 amps.

For voltage drop there are a number of calculators on the web. Here is one http://www.southwire.com/voltagedropcalculator.jsp

Keep in mind that when you measure the length of the circuit you need to account for both directions. The length of the wire from the battery and the return.

Hope this helps

 

[drewpster]

Re: wire size

Check out the link below. I think it can help.

http://www.midcoast.com/~aft/index2.html