Comments please wiring battery and instruments

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cyberpunx

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hi all,
thought i would post this i just finished it with smartdraw, and would appreciate your feedback or anyway it could be improved..
the second pic is the standard volvo penta wiring ive just joined the 2 connectors together.
but i would like comments on size of fuses and type thats best and any ideas on making the circuit better.
regards john
Boatwiringmine.jpg

scan0064.jpg
 
As an electrician I'm sure you know this but unless your -ve busbar is connected to the battery -ve not much current will flow through your various circuits /forums/images/graemlins/smile.gif
 
Connection of the negative busbar has been mentioned.

In order to advise on the fuse sizes it is really necessary to know the current load on each circuit. What are they all?

You show a bilge pump connected directly to the battery via a float switch. You need a fuse in that circuit! I would also, I think, include an isolating switch and a manual over ride switch by passing the float switch.

Separately you indicate a fuse, switch and circuit no 5 for a bilge pump. That is presumably a second pump on purely manual control but is it really necessary?

You will also need to consider the size of the wiring bearing in mind that you need to minimize voltage drop on 12 volt circuits.

You might find this cable sizing calculator useful
http://www.unlimited-power.co.uk/cable_sizing.html

Another link you might find useful is this one on boat electrics although for an electrician I appreciate it is a bit basic
http://www.tb-training.co.uk/cover.html

You may also find The 12 volt Doctor's Practical Handbook useful (It's a big file so give a few moments to download)
 
The omission of the negative connection has been mentioned (twice) and acknowledged.

Do wake up there at the back /forums/images/graemlins/grin.gif
 
You will find that you can use very very expensive marine cable to wire it all up in. Or you can use the double insulated and colour coded cable used for meter tails to provide the heavy duty side to and from battery, isolater, and to the bus bar systems.
I used 10 way lorry cable from the bus bars and fuse system to each cabin x 3, and to the cockpit. All neatly colour coded and good for 32 amps at 12 volts per pair. Solder the ends then crimp.
Finally Brays law says that you will find twice as many devices to fit the system as when you planned it!
 
I am not going to get drawn into the tinned marine cable vs untinned cable argument but as far as tinning the ends of cables is concerned some will say you should not do that as vibration will cause fatigue and ultimately failure if you do. However if your are going to tin the ends then why not crimp the terminals on first and then solder them as well. That way you will eliminate all possibility of poor connections. I reckon if the cables are properly supported then fatigue due to vibration can be eliminated.
 
Apart from whats already been said twice, if it was my boat I would get rid of the battery switch and fit seperate switches with a VSR easy when you know how! /forums/images/graemlins/crazy.gif
 
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