New Electrics

[sparerooms]

The PBO book is this one by Garrod http://www.amazon.co.uk/Practical-B...ie=UTF8&qid=1389649379&sr=1-4&keywords=garrod

Not seen it personally but I have the PBO articles on which it is based. It is probably nearer to what you need than Calder's book.

My comments,( as a longstanding owner of a similar sized boat.

Battery .... 60 or70 Ah probably sensible minimum size unless you plan on fitting a load of power hungry equipment then get bigger, but the bigger they are the heavier they are. Mine new last year is this 60Ah one http://www.tayna.co.uk/LFD60-Varta-Professional-DC-Leisure-Battery-930060056-P3635.html

Decide what you what to fit. What you need in the way of lights etc and other equipment. I'd not bother with an electric bilge pump!

Make or buy a switch panel with enough spare switches and fuses to accommodate extra stuff which you will fit in time.

Wire every thing with twin flex .. tinned is best and probably worth while for wires that go outside eg to light fittings even if you dont bother else where.

Use a minimum size of wire for the low current stuff that is robust. For other stuff ensure you use a wire that is heavy enough ( surprising how heavy that can be on long runs ) to keep volts drop to an acceptable level.

Charging .. small outboards usually are inadequate unless you run them for long periods at highish revs. I tried but now have a small solar panel. Mine is 5 Watts but 10 w would be better if the space is available to fit one.

LEDs for lights are expensive but keep the current drain down, then you can keep the battery size down Only my tricolour is LED but if I were refitting the interior again I fit LED lights inside even if not the deck level Nav lights

FWIW the wiring diagram of my switch panel below. Not suggesting you follow it just posting it for ideas ..... It would be a bit different if I made a new one anyway

ok I'm confused! If I use twin cable how do I get all the positives to the switches and all the negatives back to the battery?

I really do hope I can get my head around this electrics malarky

 

[AngusMcDoon]

ok I'm confused! If I use twin cable how do I get all the positives to the switches and all the negatives back to the battery?

I really do hope I can get my head around this electrics malarky

Boat switch panels usually have a big common connection for the positive from the battery from which all the switches take their power. For the negatives get something like this...

and connect it to the battery negative with a thick cable.

 

[ghostlymoron]

ok I'm confused! If I use twin cable how do I get all the positives to the switches and all the negatives back to the battery?

I really do hope I can get my head around this electrics malarky

To separate positive and negative cores, just cut back the outer cover of the twin cable to expose the inner cores which can then be terminated at earth and switch respectively.

 

[sparerooms]

So only the positives get wired to the switches? And all the negatives all go through the buzz bar, is that correct?

 

[AngusMcDoon]

So only the positives get wired to the switches? And all the negatives all go through the buzz bar, is that correct?

Switch panel only has 2 switches, doesn't show fuses or main isolators, but like this...

There will be a negative connection to the switch panel as well if it has LED's to show when a circuit is on.

 

[sparerooms]

Its all starting to make sense now, thanks to everyone for all the input