if i understand u right, then ur saying that this is what u should do:-
in which case all ur doing is fusing the same wire twice and should anything happen after the second fuse, then the cap will discharge into the chassis as its not seperated
if i understand u right, then ur saying that this is what u should do:-
in which case all ur doing is fusing the same wire twice and should anything happen after the second fuse, then the cap will discharge into the chassis as its not seperated
yup thats pretty much it mate. When using a fused distro block (as you should really be) then its not an issue. If using a non fused block then you have extra potential for disaster but the amps will be fused anyway with their own fuses.
that depends on where ur connecting the cap to, and also where the block is fused, if at all.
as i said the problem with ur theory is ur fusing the same bit of wire twice which is a waste of time money and effort.
and if, like u assume the distribution block is fused, then there is absolutely no need for ur second fuse as the block is doing it anyway.
ah but if the cap connects before the block then you need a fuse alrightOriginally Posted by Kev
You have to fuse twice as you have 2 sources.
Personally Id connect like this. same amount of fuses as yours just a different layout. Also cheaper as your distro block doesnt need 2 x 0g inputs.
Its very similar to having a relocated battery to the boot. you need 2 fuses in that case also.
Last edited by pablo; 19-02-2005 at 18:49.
indeed u do, however the reason for that is a power supply at both ends.
ie the battery and the alternator.
once again, the problem with ur way of doing it, is that should anything happen after the second fuse....... bye bye cap and bye bye some electronics, the worry is not for the amps
just for referance btw, i have 2 batteries in my boot.
both have a fuse on the distribution box and have medium gauge cable running the 200mm between the batteries and the box, and the other side of the distribution box has the thicker gauge cable which has no fuse, until it gets to very near the front battery.
this is the way it should be done, ie, that u have a fuse as close to the power source as possible, be that power source battery or capacitor.
exactly - fuse close to the cap
Can I just add something here, the reason I did the first diagram was to check that I only needed a single cable running from the distribution block to the cap. From above arguements I will be fusing that spur in order to protect the cap.
the distribution block I will be using is un fused as I have yet to see one that can take two 0 gauge cables, although my system is probably going to run in 4 gauge now due to me being able to get some really high spec cable that will take 300+ amps sustained at 12V. I think this will be more that acceptable oh and just to the cable has no real power loss characteristics till runs are more than 15m.
mate if you wired my way you wouldnt need a distro with 2 0g inputs which is exactly why I did mine that way.
but.....4g would most likely be plenty to be honest. With a 100A fuse up front should be 100%
Kev, goodlad.
Pablo, u dont get it..... and i dont think u ever will.
the cap is another power supply, but u dont want to fuse it, thats just plain silly far as im concerned
pablo but in your way of conecting it you also requires two cables on the cap (one feeding from the battery and one returning to the dist. block), where as mine only requires one and I am trying to minimise the amount of wiring I am going to have in the boot.
sorry lads -
kev - I dont think we will agree on this one. Ive had an identical (ish) system and Im going on my own personal experience.
kkydd - two ring terminals on the + of the cap is perfectly acceptable and means less cabling really. The run from the cap to the distro can be very short.
Its down to this really - the cap is a storage device just like a battery and as such has the potential to cause a spark. it should have the appropriate fusing in place to protect the 3m odds of power cable running up the car in the event it shorts to the chassis. Not likely to happen but it could so the choice is yours. Fuses for 0g are expensive surely but if you are using 4g then its what? £4 for a fuse holder and fuse? Wont affect performance and wont lose you quality so whats the harm?
imagine the cap was a battery - would you fuse it then? The front battery is fused after all.
the cap is in effect a battery, its u who is choosing not to fuse it with ur set up.
all ur doing is isolating it from the front battery, ur not helping fuse the cap at all.
if for instance the car is in a rear ender, the wire in the boot could be compromised, and uve just let the cap disscharge into the body.
u fuse the cap as another power supply, nut just seperating it from the main supply
the fused distro should protect the boot of the car. have the fuse dangling off the cap if needs be but better to have one in there someplace.
Ive already said your diagram was correct but isnt the way Id do it as it required a distro block with 2x0g inputs = £££ and more cable
i know u reckoned my way was correct, but im saying as far as im concerned urs isnt.
and if ur going on about the distribution box being fused, then again ill say there is no need for u to double fuse the same wire
each fuse has a different role:
the 100A up front protects the 0g run from the front battery in the case of a short
the 100A down back (before the cap) protects the same stretch of wire from the cap
the 2 40A fuses in the distro protect the smaller runs from the batt/cap (usually smaller gauge such as 8g)
the 2 40A fuses in the amps are a last resort protecting against shorts internally
That IMHO is the correct way to wire an install such as this. In reality it can be done differently with a non fused distro (a ground distro block really) but thats not the way Id set out to do an install.
From a purely outsider's point of view ('ICE' - wossat then ?)
I'd go with Kev (I think) and put the fuse right at the battery, and one right at the capacitor +ve terminal, then you don't have to worry about junction block fusing etc, and every last mm of wire can be shorted and a fuse will stop something exploding.
I must try and get one of these 1F caps and have a play, cos one farad's chuff-all in energy-storage really - what's the short-circuit current on them, and do you need ultra-fast-blow fuses to catch it? (Curious really - not making any statements
Oh and hi
fair dues mate - just saying the way Id do it
John I got it form Maplin but they are made by poweramper their web page is www.poweramper.com
no, it won't. 12V is 12V The fact that there is a billion farad attached, doesn't make the voltage any higher, and therefor any more dangerous.and try not to touch the contacts on that cap, thats gonna tingle!
yes, if you put your tongue accross the terminals, you will know about it, just like a pp3 battery.
When I did my A level in physics, the lecturer explained that it was current that killed you, not voltage (think he used the van-de-graph generator to proove his point. ) he said this is why you have to be carefull of the car battery, because it can deliver a lot of current.
being an older student and having just finished 5 years of electrical/electronics at collage, i challenged him. we ended up in the car park, with me touching both terminals of my car battery......
however you do not want to drop a screwdriver on the terminals!
as for fusing, i'm with kev
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