my loads are one bog standard car stereo, one six inch long 12v flourescent light and one 12v socket.
how is it so complicated?!
can anybody tell me what size cable and
fuse to use on this, which must be the simplest circuit ever in a campervan?!
Firstly let me apologise on behalf of myself and no doubt other regular supporters of this forum for the way that your thread has been hijacked by some newer contributors in order to promote their own agenders and pass irrelevent and inaccurate comments. I can also assure you that there are many helpfull people on here who do try to give practical and useful advise.
Back to your question, no its not complicated, but to be safe you will need a small understanding of cable sizing and loads.
Firstly allways use proper automotive type cable, this should always labled with a number like this "
14/0.3 " where the first number (14) is the number of strands of wire and the second (0.3) is the diameter of each strand in mm. All of the cable you need to be concerned with will have 0.3mm strands, so the greater the first number the higher the current carrying capacity.
The common cables and their approximate rating in Amps are :-
9/0.3 - 5A
14/0.3 - 8A
28/0.3 - 17A
44/0.3 - 27A
65/0.3 - 35A
These ratings are for continuous use.
For your installation my suggestions for minimum sizes would be:-
Flourescent light - this is probably 8W so uses less than 1A although start up current is higher. 9/0.3 5A cable fuzed at 3A will do. (if a fixed/hidden cable consider using 8A as this would allow extra lights in the future).
Car stereo - Some cd units require up to 15A (unit should have a
fuse rate marked on the back) so use min. 28/0.3 17A cable fused at 15A or as appropriate.
12V socket - Not sure what type of socket intended use but if 2 pin wire and
fuse for 15A (as above) or if cig lighter socket use 65/0.3 and
fuse at 30A.
If
fuse box is next to the
battery wire directly to each
fuse, is mounted away use heavy duty (50A)
fuse next to the
battery and run (if using 30A socket) 84/0.3 (50A) cable.
From your original post, you can run yor returns (negative's) back to the
battery, use same size cable as feeds (positive's).
For primary charging of leisure
battery forget
solar unless you have money to burn. In the UK your daily average charge from each 100W of
solar panel is 2A/H.
Fit a split charge relay, use a smart one, they are so simple to wire up, but always use at least 35A cable (preferably bigger), keep cable run as short as possible and ensure all your connections are as good as they can be. When up and running I like to see less than 0.2V voltage drop from alternator to leisure
battery.
I have tried to make this post as simple as I can but still give enough information for you to safely proceed, and I hope you can isolate it from the pile of irrelevance that this thread has created.
10amp for skt and stereo and 5amp for light