Which side of the distribution block should the inline fuse be?

Maheriano · 06-16-2006, 12:32 AM

Should I put the inline fuse for the amps on each amp power wire going into the distribution block, or just one on the other side going to the battery?

Basically I plan on running 8 gauge from the battery to the distribution block and then another two 8 gauge from the distribution block to the amps. And somewhere in there I'd squeeze the 18 gauge power wire for the computer. Any problems here?

2k1Toaster · 06-16-2006, 12:50 AM

I would put a big one one the main line close to the battery. And then a fuse for each "accessory" on the power distributor, close to the distributor. That way if 1 thing is bad, the individual fuse blows, and if something catastrophically bad happens, then the big one blows. Always good to have a contingency plan too, so 2 fuses essentially to each device is good, in my opinion.

bob^ · 06-16-2006, 05:52 AM

Not to mention the smaller cables comming out of the distro block have a lower current rating. Whilst you might have a 250amp fuse near the battery which is fine for the main cable, 4 guage would melt with less than 250 amps I'd say, and you can see where that would lead to.

hunterius · 06-16-2006, 06:03 AM

250A fuse will stand even starter

anyway one big fuse on main cable max. 30cm ( 1 feet) from battery and if you will notable lower cross-section of wires running from distribution block it is definitely good idea put smaller fuses on each wire right behind the block.

Maheriano · 06-16-2006, 08:31 AM

So what size fuses do you think I need for these?

computer
120 watt 4 channel amp
250 watt mono amp

hunterius · 06-16-2006, 08:48 AM

there is simple formula : wattage peak + 10%

if your numbers is peak so let say:
-main source 90 - 100A fuse

if your wires from distr. block is short enough , apms and PSU has its own fuse, so you don't need any other fuses. But I think that your 8awg wire from battery to block is insufficient ...you need 4awg.

and here is recommended maximum fuse for vary wires
00 awg 400 amps
0 awg 325 amps
1 awg 250 amps
2 awg 200 amps
4 awg 125 amps
6 awg 80 amps
8 awg 50 amps
10 awg 30 amps
12 awg 20 amps
14 awg 15 amps
16 awg 7.5 amps

and here http://www.bcae1.com/wire.htm you can find a lot of information you need

Maheriano · 06-16-2006, 09:24 AM

Okay, so here's my plan of attack then.

4 gauge wiring from battery to distribution block in trunk.
125 amp fuse in this wire near battery.
8 gauge wiring from 250 watt mono amp to distribution block with 50 amp fuse.
8 gauge wiring from 120 watt 4 channel amp to distribution block with 50 amp fuse.
Computer power wire to......????

hunterius · 06-16-2006, 09:29 AM

how long will be wire from block to amp?

for carputer you need wire rated for at least 10A ( I am not familiar with awg sizes 'cause I'm from europe

but I think 14awg will be enough )

Maheriano · 06-16-2006, 10:16 AM

The amps and computer will be in the trunk and I guess I can put the distribution block anywhere it needs to be. I was thinking about the trunk to cut down on the length of wire from the amps to block.

hunterius · 06-16-2006, 10:20 AM

so once again

if your wires from distr. block is short enough (about 2feet) , apms and PSU has its own fuse, so you don't need any other fuses put to wire.

Maheriano · 06-16-2006, 11:07 AM

So no inline fuse from amps to block? Is that safe? Sorry, I just need to be explained how the length of wire matters. I'll check the site you posted as well to see if it's there.

hunterius · 06-16-2006, 11:19 AM

I think it is safe 'cause shorten wire is less possibility of accident and little sparkling

and short wire even thin is able blow main fuse without melting.