Leisure system wiring.....no fuses!

[chippieshaun]

I have been sorting out the wiring in my camper as it is a hell of a mess.
I have a main supply from the leisure battery to a junction box which then supplies all normal camping stuff (propex, interior lighting ,water pump,fridge ignition,12v socket , etc) I have just re-wired the propex and added a 5amp in-line fuse but none of the 'original' wiring has fuses! Am thinking that this is quite dangerous.

My question is - should the supply to each separate device have it's own fuse (am thinking water pump and fridge ign) and should i also have an in-line fuse between the leisure battery and said junction box???

Hope this makes sense!
Any advice appreciated.
Cheers
Shaun

[Rozzo]

hi
mines in the same crappy state.
i'd say yes and yes to your questions. the one on the lead from the battery should be as close to the battery as possible to protect the most part of the wire.
gonna attack mine over christmas and sort it out.

[1664]

You should have a fuse protecting the cable that charges your leisure battery from the driving battery / alternator. The relay should be fused too.

A fuse to protect the wiring to the junction box - this could also protect the connected equipment depending on what size it was.

Generally the fuses should get smaller as you leave the power source out to the equipment to give what's known as 'discrimination'.

For example

25A for charging circuit to leisure battery
15A to protect relay
15A leaving leisure battery
10A or 5A to each piece of equipment (depending on size of load)

This way if you get a fault on your water pump or it's wiring you blow the 10A/5A fuse but leave the others intact so you still have lighting, fridge etc.('discrimination'). If you left the final 10A/5A fuses out you'd blow the 15A so you'd lose everything when the fault may only be on one piece of equipment or wiring.

You have to rate the fuses in proportion to the size of the wiring; the above example is how mine's done. I've never seen wiring smaller than 1.5mm used in a van which can easily take up to 20A but if yours has been slung in by a bodger it'd be best to check sizes.

Bottom line, any fuse is better than none.......

[chippieshaun]

Thankyou very much for your replies.
Mr 1664 , that is very good advice and gratefully received!
Will be sorting it all out at the weekend.