What fuse to use?

**Meelobee** · 10-07-2005, 10:46 AM

Excuse me for the stupid question but I'm a total noob with voltages, ampere's etc...

Comming weekend I'm re-doing the cabling for my carpc. Now I use a 12v output in the boot to power my pc, but this 12v output gets cut of when I start the car, so the pc must be off everytime I start, that kinda beats the purpose of having a M1-ATX.

I've let my dealer put a wire from the battery through the firewall (this is almost impossible to do yourself on a Golf5) I've used a wire (from this set) that is normally used to power a 500Watt (max) amp. The wire has an inline fuse just after the battery. There is a 30A fuse in it (stock)
Since I'm using the wire to power only my carpc I think the 30A fuse is too much? (right?!)

I'm using the following components:

M1-ATX PSU
Epia SP13000
512Mb DDR
BU-303
Lilliput 7" (now runs on 12v cig output, but I'd like to add that to the M1-ATX, if possible)
60Gb 2,5" Hdd (7200Rpm)

To savely protect this from shortcuts and whatnot, how much ampére does the fuse need to be?

And a bit related to this question, can I use any bare metal as a ground (-) point?

**HHdesign** · 10-07-2005, 10:54 AM

I can answer your ground question but not your fuse...

Make sure you have a good clean spot of bare metal, if you need to get a dremel and shave it down, no paint/ primer around it, otherwise yes any ground point is fine.

**Will Albers** · 10-07-2005, 11:22 AM

30amp is fine. Its going to protect you from a dead short.

If you are nervous about it, try a 10 amp fuse. If you pop it, try a 15, if you pop it go for a 20...

Most systems draw a ton of amperage when booting so it should happen farely quickly.

**Scouse Monkey** · 10-07-2005, 11:24 AM

10 should be spot on but might blow duing crank in which case go for 15.

**Meelobee** · 10-07-2005, 01:05 PM

What happens if the fuse is too little ampere? Will I damage anything on my system, or will the fuse just blow then?

**IntellaWorks** · 10-07-2005, 01:07 PM

I use a 10A fuse for my car pc, nothing else is on that line.

**turbocad6** · 10-07-2005, 01:12 PM

I would leave the 30 at the battery.... this fuse is to protect the wire not the pc.... I would then use a smaller apropriate fuse at the pc.... a 10 sounds about right....

this will also allow you to add to this circuit in the future.... you can add another circiut off that wire & independantly fuse that particular add on individually as well..... this is the way the factory does it btw...