wiring for my amps

[lazybum 10+ year member]

would a 4 guage power wire from the battery to the trunk be ok for 2 polk momo amps? c400.4 pushing 75 watts to 4 channels and a mono amp, c500.1

I dont have the mono amp yet but I plan on getting it and getting 2 10" or 12" polk momo subwoofers and wiring them for a 2 ohm load.

so I guess the total wattage would be (75 x 4) + 500 = 800 watts

c400.4 has 2 x 30 amp fuses

c500.1 has 2 x 25 amp fuses

total amps = 110 amps.

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[Raffi 10+ year member]

Should be fine!

 

[AzGrower 10+ year member]

You CANNOT use your current draw to determine fuse ratings needed. You use your current draw and overall run length to determine the size wire you need. Then you match the fuse to your size wire you are using.

 

[Chevyaudio 5,000+ posts]

The wire size is fine, just do what AzGrower said, don't add up fuses to get the fuse amount for your power wire, Fuse for the Ampacity of the wire and the length of the run.

 

[AzGrower 10+ year member]

Suggested Fuse Sizes:

Wire Gauge Recommended

Maximum Fuse Size

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

These are the recommended maximum fuse ratings for the corresponding wire size. Using a smaller fuse than what's recommended here will be perfectly safe.

 

[RandyJ 10+ year member]

Curious, why would he match his fuse to his wire size. Are you telling him to use the max which his awg/length can handle?

 

[RandyJ 10+ year member]

You tell him to match his fuse to his wire, not to his current draw, then tell him using a smaller fuse is safe, which is it guy.

FYI, I know my stuff, im just trying to decipher wtf it is you are saying.

 

[AzGrower 10+ year member]

Curious, why would he match his fuse to his wire size. Are you telling him to use the max which his awg/length can handle?

Because the main purpose of the fuse is to protect the wire length behind the fuse. So your fuse needs to be matched to the wire. NOW you can safely use a fuse that rated smaller no problem. Like a 4 gauge wire is rated to use no larger than a 125 amp fuse, but you can use a 100 amp fuse with no problems. You just dont want to use a 150 amp fuse on a 4 gauge wire. What this will do, by using a larger than the maximum rated fuse, when there is a short or ground problem, the fuse WILL NOT blow, causing the wire to burn, or worse, fry your amp. Either ways its dangerous and you can cause a vehicle fire.

He can use any size fuse UP TO the maximum rating for the wire. Its just not a smart idea to use a 20 amp fuse for 4 gauge either, cause you are gonna go through fuses like stink. Since those are rated so low that just the start up peak of amps will cause the fuse to blow (on larger wires like 4 or 2 gauge)

 

[AzGrower 10+ year member]

You tell him to match his fuse to his wire, not to his current draw, then tell him using a smaller fuse is safe, which is it guy.
FYI, I know my stuff, im just trying to decipher wtf it is you are saying.

He should determine what size wire he needs, then use an appropriate sized fuse.

What he was doing was using his total current draw to determin fuse rating, which is wrong. He needs to use total current draw to determine wire size first.

I didnt think I made it that difficult to understand, especially for someone who "knows their chit".

 

[AzGrower 10+ year member]

You should remember:

1.NEVER replace a fuse with a fuse rated for higher current than the recommended fuse.

2.The physical size of a fuse is NOT an indicator of its current carrying capacity.

3.Just because a 30 amp fuse fits in the place of a blown 5 amp fuse, that does NOT mean that it's a suitable replacement for the 5 amp fuse.

Here are some recommendations for what size wire to use VS. current draw:

Wire Gauge Current Flow

0 awg 330 amps

1 awg 262 amps

2 awg 208 amps

3 awg 165 amps

4 awg 131 amps

5 awg 104 amps

7 awg 65 amps

8 awg 52 amps

9 awg 41 amps

10 awg 33 amps

11 awg 26 amps

12 awg 21 amps

13 awg 16 amps

14 awg 13 amps

 

[lazybum 10+ year member]

how many watts my amps make is not important in detetmining which power wire to use?

 

[RandyJ 10+ year member]

use 4awg, that will be fine.

 

[AzGrower 10+ year member]

how many watts my amps make is not important in detetmining which power wire to use?

Its in important, however actual amperage draw is the deciding factor. In reality, not all 400 watt amps actually put out a true 400 watts. Thats why you should base most of you decisions for the wiring based on current draw.

You stated your total power, in amps, is 800 watts correct? If you were to use that as your only deciding factor, then you would need to use no smaller than a 6 gauge wire.

Wire Gauge Current Flow Max Total Amp Power (75% efficiency rate)

6 gauge 82 amps 853 watts

Whereas your total current draw is rated at 110 amps. So you would need to use 4 gauge wire (following the chart I posted in my earlier post). See the difference now?

4 ga compared to 6 gauge...in which the 6 gauge is only rated to handle 80 amps safely...

 

[RandyJ 10+ year member]

He should determine what size wire he needs, then use an appropriate sized fuse.
What he was doing was using his total current draw to determin fuse rating, which is wrong. He needs to use total current draw to determine wire size first.

I didnt think I made it that difficult to understand, especially for someone who "knows their chit".

Sorry, didnt get the fact that you were trying to tell him what wire size he needs to use first. Thought you were trying to base the size of the fuse he needs on the size wire he was using.

To th origional poster, 4 awg will be fine, im not sure of all the fuse sizes but use someting around 100A.

 

[RandyJ 10+ year member]

If you know your current pull, then watts is actually not important when deciding AWG.