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dusty2221
12-08-2010, 04:31 PM
Can someone point me in the right direction please? In redoing the stereo, I am adding a distribution block to split the power to all 4 amps. I am using 8g from the block to the amps for power, and believe I need to use 0 from the battery to the block. My question, all the fused blocks I have found offer two Og inputs to four 8g outputs. Is is necessary to use BOTH inputs, or will it function just fine using only 1?

Also, is 0g the recommended size to split to four 8g, or would 4g work jsut as well as the main power supply to the block?

Thanks

sandm
12-08-2010, 06:21 PM
personally, use 0 gauge, use only one, and make it a somewhat short lead. I used 0 and they are around 2.5ft total length from battery to dist. block, running 3 med-sized rockford fosgate power series amps. you don't need to use both sides.

MLA
12-08-2010, 06:32 PM
Most common blocks with two inputs are a BUSS style input, so filling both inputs is not always needed.

I like to use non-fused, also called ground distribution blocks, and then use a marine-rated manual-reset circuit breaker for the positive trunk line from the battery to the block.

The wire gauge will depend on the load it will carry and the length of the run.

cab13367
12-08-2010, 11:33 PM
Can someone point me in the right direction please? In redoing the stereo, I am adding a distribution block to split the power to all 4 amps. I am using 8g from the block to the amps for power, and believe I need to use 0 from the battery to the block. My question, all the fused blocks I have found offer two Og inputs to four 8g outputs. Is is necessary to use BOTH inputs, or will it function just fine using only 1?

Also, is 0g the recommended size to split to four 8g, or would 4g work jsut as well as the main power supply to the block?

Thanks

Dusty,

Please see the table in the link below. To answer to your question as to what gauge cable you should use for your input when using (4) 8 AWG outputs - you want the size of the input (cross-sectional area) to be equal to or greater than the cross sectional area of the (4) output cables added together. So according to the table, (1) 2 AWG cable has a cross sectional area that exceeds the cross sectional area of (4) 8 AWG cables so (1) 2 AWG cable is fine for your input assuming you have a relatively short run from the battery to the distribution block.

Hope that helps.

Al

http://en.wikipedia.org/wiki/American_wire_gauge

dusty2221
12-09-2010, 09:20 AM
Thanks guys. 2 is what I had wanted to use.

MLA
12-09-2010, 12:26 PM
The downside to the above rule-of-thumb from wiki, is that's its assuming that the 8ga is of adequate size for each amp to run from the block to the amp.

Depending on each amp's potential current draw, and the distance from the block to each amp, 8ga may or may not be sufficient. You may need 4ga, so this would change the whole equation.

The wire ga chart I use has 8ga carrying up to 60A for a length of up to 5ft. In most installs, the amp will not be more then 5 ft from the distribution block . More then 60A or further then 5ft, you should step up to 4ga.

In the grand scheme of things, wire is inexpensive, so you would only be talking a few bucks more to step up to 4ga for all 4 amps. $.02

cab13367
12-09-2010, 03:00 PM
The downside to the above rule-of-thumb from wiki, is that's its assuming that the 8ga is of adequate size for each amp to run from the block to the amp.

Depending on each amp's potential current draw, and the distance from the block to each amp, 8ga may or may not be sufficient. You may need 4ga, so this would change the whole equation.

The wire ga chart I use has 8ga carrying up to 60A for a length of up to 5ft. In most installs, the amp will not be more then 5 ft from the distribution block . More then 60A or further then 5ft, you should step up to 4ga.

In the grand scheme of things, wire is inexpensive, so you would only be talking a few bucks more to step up to 4ga for all 4 amps. $.02

Agreed, and I was going on the assumption that Dusty had correctly sized the 8 AWG cables to the amp. I personally used 4 AWG.

MLA
12-09-2010, 03:22 PM
Agreed, and I was going on the assumption that Dusty had correctly sized the 8 AWG cables to the amp. I personally used 4 AWG.

I understood that and didn't mean for it to sound like I was calling you out :oops: and just wanted to add to that for others fallowing along.

Razzman
12-09-2010, 04:07 PM
I would use no less than 4 gauge to the amps. I've also used a short run 4 in from batt / two 4 out to amps many times with no adverse effects. In fact may current system running a Harpoon & ZX700.5 was wired that way and has plenty of power (until i gutted the entire system three weeks ago). What looks good on paper doesn't always reflect real world results.

Quality wire and cable is also important and as said KnuKonceptz (http://www.KnuKonceptz.com) is the best online source i've found. Been ordering from them for four years now and it's quality stuff.

sandm
12-09-2010, 04:10 PM
4awg here and 0 to the ground block. I figure that in a marine environment where the engine may not be running for extended periods of listening, give the amp the ability to draw all it can.

now in my truck, my old-school soundstream 405 is running on 8gauge and does just fine :)