electrical help need advice

[Kracker Jack]

So im fairly familiar with marine wiring........Fairly.how do I know what amp I want to run on each switch? is there a formula? and also lets say im running multiple lights on one switch, would I connect each light to one terminal and then run a single wire from the terminal to the actuall switch itself? all advice, tips and short cuts are welcome. and maybe elaborate on what gauge wire I should use to run my lights and other electronic items.

Just to let you guys know im going with a dual battery setup with a 1-off-2-both battery selector. The electronics will be protected by a sea sense 10 position fuse box. Heres how i would like my switches

#1 switch type- (on-off-on) running lights (all around light, 2 seperate red/green bow lights,stern light,compass light,tach gauge light)

#2 switch type- (on-off) all electronics kill switch (vhf,gps,stereo)

#3 switch type- (on-off) courtesy lights (t-top leds,bilge leds, 2 side console leds)

#4 switch type- (on-off-on) led accent strip lights under gunwale (2 cool white 16' continues led strips, 2 blue 16' continues led strip lights) note-I will have the option of using just the white leds or using just the blue leds, never both at the same time.

#5 switch type- (on-off) deck level sump well bilge pump with float switch (I will have a 1100 rule pump with a float switch option that will pump deck water over board Im gonna use the switch on the panel as a kill switch when not in use)



#6 I will have a seperate (manual- automatic) rule bilge switch constant to the battery for my true bilge pump(2000 gph)


am I missing anything?

[SkunkBoat]

its tough to explain it all without seeing what you have.
I use marine grade 16AWG for most things.

To calc current draw in AMPS in a DC circiut just divide Wattage of (incandescent) bulb by Voltage 12V
(a 12V battery is actually 13.8V but use 12 to err on the high side).


So a 10W bulb draws 10/12= .83 Amps

Add up the total watts drawn on any branch and divide by 12.
3 -10 watt bulbs draw 2.5 amps.

LEDs are a different story. Best to read your packaging for the Watts or current draw but a single (individual) led may draw only 20mA (.020Amps)
You can get a lot of LED light on a little power...

16 AWG wire can safely carry almost any circiut you are going to run on a V20. Even with multiple lights on a branch. Its cheaper than 12AWG!

save wire by extending a branch instead of running separate wires.
For instance. your red/green nav lights are on same switch. run wire to the green and then from there to the red.

You could go with 12-14awg on the pumps, VHF, and any Spotlight or 12V power outlet.


http://www.westmarine.com/webapp/wcs...ge=Marine-Wire

[Kracker Jack]

Thanks BARN and SKUNK. Im still doing alot of research. I want everything to be done correctly because I have seen some cut up botch jobs on a boats. Im looking for simple, clean and functional

[phatdaddy]

try & run it in tinned wire if possible.i would do mine every 3 or 4 years until i broke down and went the extra $ and have not had an issue in 10 years now.(great, i just jinxed it)