What size power cable?

Discussion in 'OT Technology' started by Mister Mac', Sep 22, 2003.

  1. Mister Mac'

    Mister Mac' Av: Daniela Denby-Ashe in Torchwood S1Ep7

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    One of my friends just got a car and wants me to install his system. He bought a Cadence 800W amp for his subs (2x Sony 12" 350W :ugh2: )

    What size cable will I need to use for the amp? Running from main battery to trunk (about 18ft I'd guess) 4GA? 2GA?

    The amp is rated:
    300W RMS x 2 @ 4-ohms
    400W RMS x 2 @ 2-ohms
    800W RMS x 1 @ 4-ohms

    Onboard fuses are 2x 40A

    I've installed a few systems before, but nothing this powerful! :p My system has a 450W RMS amp on 4GA, but the cables are only about 3ft long.

    Will 4GA be enough for this amp, considering the length of the cables?

    Thanks.
     
  2. midnite

    midnite OT Supporter

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    i think 4 would be enough
     
  3. Mister Mac'

    Mister Mac' Av: Daniela Denby-Ashe in Torchwood S1Ep7

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    Yes, after looking at some of the amp installation kits I think you're right :) Some of the 4GA kits go up to "1800W" supposedly, so 800W should be fine :big grin:

    Thanks for the reply!
     
  4. GlocksRock

    GlocksRock Glock > You

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    4 guage will be good enough.
     
  5. Dom Toretto

    Dom Toretto ^--- Too Fast, and too furious

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  6. 04

    04 Guest

    I agree with the 4 gauge reccomendations.
     
  7. BlackHBDX

    BlackHBDX The grey fixer

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    I'd say 8 guage, 4 guage would be overkill. A 10 guage wire is good for up to 60 amps of current (and remember that most amps will never draw more than 75% of their fuse rating).
     
  8. 04

    04 Guest

    Well according to IASCA, if you don't what a voltage drop of more than 5% over the wire (which I think is a good idea) even if the amp only drew 60 amps of current, they reccomend 4awg at 18 feet.

    Now, if the amplifier puts out 800 watts, and is say 80% efficient, it is going to need to draw over 80 amps of current at full output. And when you clip it (most people clip their car amps often) you will have even more current draw.
     
  9. Mister Mac'

    Mister Mac' Av: Daniela Denby-Ashe in Torchwood S1Ep7

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    Cool, that's good to know :) I think the amp will be clipped fairly often :big grin: This customer likes his Hip-Hop :p

    Here's a pic of the completed system. I used 4GA right through.

    [​IMG]
     

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