99 replies to this topic

[freshairmini]

I've used the12v and http://www.bcae1.com/ to work out the wiring needs.

12 awg to the sub gives 0.04db loss.
16 awg to the comps gives 0.15db loss.

Using 4awg from battery to dizzy and 8awg from dizzy to amps results in a 0.2v loss which isn't markedly improved by changing the gauge even up to 0awg.

The P4 draws a max 20amp rated 25amp fuse, the Psub 30amp with 2x30amp fuses.

Working from the12volt basing the fuse on the wiring used, I should have 2 x 100amp fuses in the dizzy block.

Is this correct?

I think that 100amp fuses for 12 and 16awg wire will be way to large. According to that website the largest fuse you should use for 12 and 16awg is 20 and 7.5 amps respectively. 12 and 16awg seem way to small!

From what that website says, and my knowledge you should have two 50amp fuses in the distribution block for the 8awg. after that I'm not sure what size wire you would need to feed the dizzy block. 4awg maybe and 80amps maybe, not sure tho.

I've been using 8awg with my genny. (profile sub). at that size the maximum needed would be 50amps. Remember your fusing for the wire not the amp. if the wire was to short at 12 and 16awg the wire would melt before the 100amp fuse would blow.

Edited by freshairmini, 15 October 2012 - 08:40 PM.

[Skortchio]

Why would I fuse the signal wire?

I think I'm confusing people here.

The power will be provided by a 4awg from the battery, to the dizzy block. Which in turn will provide power to the amps via an 8awg cable each.

Given the cable is 8awg, is 100amp the correct size fuse to be used in the dizzy block? Based upon the chart in the12v.com

Edited by Skortchio, 15 October 2012 - 08:42 PM.

[freshairmini]

sorry my mistake about the speaker wire!

but still 100amp is too big for 8awg, you need much less than that. The below is taken from that website:

Edit: the wire/amp table wouldn't keep the formatting. Long and short of it was that the max use to b used with 8awg os 5amps 125amp for 4awg

Edited by freshairmini, 15 October 2012 - 08:45 PM.

[Skortchio]

Okies, thanks for the clarification!

I was using this table listed here http://www.the12volt...fo/recwirsz.asp as power and ground cable specs, showing 8awg at 100amp.

Headphones were so much easier than this

[freshairmini]

Ha headphones are much easier.

but for reference on this website its about 1/4 way down page, below a power/voltage loess diagram: http://www.bcae1.com/wire.htm

Edited by freshairmini, 15 October 2012 - 08:50 PM.

[Skortchio]

I've used the12v and http://www.bcae1.com/ to work out the wiring needs.

12 awg to the sub gives 0.04db loss.
16 awg to the comps gives 0.15db loss.

Using 4awg from battery to dizzy and 8awg from dizzy to amps results in a 0.2v loss which isn't markedly improved by changing the gauge even up to 0awg.

Ha headphones are much easier.

but for reference on this website its about 1/4 way down page, below a power/voltage loess diagram: http://www.bcae1.com/wire.htm

I know

[mini-luke]

It's better to under fuse that over fuse, 100a on 8GA is pushing it even for a short distance, that's what I'd fuse 4GA at. For the length of cable, I'd be inclined to run 4GA to the amps.

[Skortchio]

For what benefit?

The current draw isn't enough that i'll suffer voltage loss with 8awg.

[mini-luke]

100A is over fusing the wire, that's why. If you only need 50A fuse it for that.

[Skortchio]

That's what I was asking initially, which fuse was required to match the cable being used.

All done now.

[mini-luke]

A note on voltage drop. Although over a short distance there will be an insignificant voltage drop putting 50 or 60A though 8GA there will be a lot of heat created, which is borderline dangerous at 60A as it can be enough to melt the insulation.

[Skortchio]

Okay, but given the amps draw a max of 30amp that shouldn't be a concern in my particular case, correct?

[mini-luke]

Okay, but given the amps draw a max of 30amp that shouldn't be a concern in my particular case, correct?

No, not at all, if it really does only draw 30A. Though the draw of 30A is given at 4ohm, producing 350w. Translate that to 2ohm making the 564w it's birthsheet says and you get 62A at 60% efficiency and 14.4 volts. Drop the voltage a bit when you are pushing the system and you can see why the amp is fused at 60A.

http://genesis-ice.c...ofile-range.php

Edited by mini-luke, 15 October 2012 - 09:28 PM.

[Skortchio]

Right, so by that information I'm better off ditching the dizzy block and running an 8awg and a 4awg right off the battery (fused inline) 8 to the P4 and 4 to the Psub?

Better?

[mini-luke]

What cable do you currently have? I'd run a 4gauge fused at 100A to a dizzy block, then an 8GA fused at 50A to the P4 and a 4GA fused at 100A or less (60 should do it) to the P-Sub. You could probably get away with running 8GA to the P-Sub and fusing at 50A but it depends how much you want to run the risk of needing to re-wire in the future if the fuse blows?

If you've got enough cable a 4 and 8ga run to the battery would be more than ample and save a dizzy block, remember you can't over wire it!