Wiring and fuses

[Alan2016]

I am wanting to put in a couple of din sockets to run a coolbox and a compressor/tyre pump. The coolbox says it can draw up to 48w.

I plan to put one socket at the rear of the van and another near the back of the sliding door. I have some 56/0.30, 4.0mm², 39.0A thinwall cable, would this be suitable to run from the rear of the van to the bonnet and into a fuse box? What size wire would I then use from the fuse box to the battery, the same or something thinner, and what size fuse?

Finally would I be ok to piggyback a double USB socket off the same cable as the din or would I need a separate cable? These would be for charging phones etc when the din isn't in use.

Thanks

Alan

[g8dhe]

The normal outlet sockets are rated for 10 Amp, but given the length of run a more substantial cable as you are suggesting is worth while.
Fusing I would go for 20Amp as its unlikely that you would be using both sockets at the same time to full power.
From fuse to battery the cable size will depend on how many fuses and total current drawn, if its a single fuse then the same cable as your using is fine and given the size of cable your using it would be good for several fuses anyway, but keep the run short, remember that length of cable is unprotected by any fuse.

[Alan2016]

Great stuff, thanks!

[Alan2016]

Quick question about fuse boxes...I currently have one of rooster's kits for swapping over the blinds etc. This goes into a little 4 fuse box with connectors along each side. 4 of these connect to the battery via 4 wires bound together with a single ring connector at the battery end.

If I want to add another 4 fuses what is the best way to do this? I see I can buy an 8 way box similar to the 4 way one I currently have and make up another cable similar to the Rooster one but that starts to make the battery terminal a bit crowded as there is already the above cable plus one for the split charging system? Am I better off with something with a common power bus?

If I had more space something like this looks ideal http://www.autoelectricsupplies.co.uk/p ... ategory/63 but it is for the wrong side and a bot large anyway.

Thanks

Alan

[g8dhe]

Before you add extra fuses what will the circuits be powering ? Simply because some of the circuits are not heavily loaded anyway like the blinds and you can make use of the same fuse depending on just what is to be connected and if they will be used at the same time.
Another source of parts and fuse holders is this company http://www.vehicle-wiring-products.eu/s ... se-holders
I like the interlocking devices as there fairly simple to expand at any time. Be careful with battery mounting cases as there isn't a lot of room around the +ve terminal of the LB for subsequent access.

[Alan2016]

Hi Geoff

Thanks for responding again. I planed to put two double USB sockets on the divers side rear (max pull about 5A per double so 10A overall. I was thinking of using 1 run for this back to a fuse. On the passengers rear I plan to put 2 Din sockets each paired with another double USB. I want either of the dins to be able to power the coolbox. I had thought of using separate runs for each of these with 20A fuses. I like the idea of keeping them separate from the existing circuits just so if they blow it only affects them.

Cheers

Alan

[Alan2016]

This was the sort of thing I thought might be simpler http://www.12voltplanet.co.uk/standard- ... 0-way.html. I thought I could maybe fuse the whole lot with something like this http://www.12voltplanet.co.uk/battery-t ... fuses.html.

[g8dhe]

Yes I do recommend the battery terminal fuses ! See http://igmaynard.co.uk/bongo/forum/view ... 21#p681521

As to the fuse block, yes that's fine saves having to common it yourself.

Be aware that with LED fuse blown lights it can be very confusing if you have a problem and start metering around as there will appear to be a voltage in some situations on circuits that have a blown fuse, also the LED's rely on there being circuit to ground to light the LED that's not always the case again in some situations!

[Alan2016]

Thanks yet again. You need to add a "buy me a pint" button to your signature, I'd have clicked it a few times by now . Re ground, is there any advantage to routing it from a socket back to the bonnet or do I just bolt it to the nearest bit of chassis?

[g8dhe]

If you mean the ground connection a good chassis connection is adequate, but personally I always run a separate return back as I've found too many bad connections in the past

[Alan2016]

Ok thanks for the tip. Final novice question (hopefully)...if I go for the fuse box with the single input from the battery, what sort of cable do I use and do I need a special tool to crimp the fittings on to it as they will presumably be bigger than the normal spade fittings my crimp tool works with?

[g8dhe]

Ah one of the sore points in life! If you want a long life to a crimp joint then yes you need the right tool for the job, which means buying either a single high price tool which has a series of jaws all at exorbitant prices, or a tool for each set of sizes all at an exorbitant prices .... They get you either way! I have a job getting onto my workshop at times because of the stacks of ratchet crimp tools trying to get out

Provided the connection between terminal and fuse box is short then the 40Amp cable your using will be fine.

[Alan2016]

Thanks again