Wire rating..

[RetroAudioinc 5,000+ posts]

I was looking around at wire before I just ordered 100' of kicker hyperflex. But I noticed a lot of welding wire said 50feet 300amps 100feet 200amps 300feet 100amps and so on these are just made up numbers but you get the idea. I total under stand why the amps go down over distance but my question is how do you know what this cable can do in say 17feet? Most cars are 15foot to 20 foot for powerwire.. So would a 20 foot run take 600amps???

Just want to make sure I understand this and how much a cable should be able to take if it's rated for 50foot plus only..

Any way to test this with a huge fire hazard or huge power bill, maybe a little math.. lol

Click to read more...

 

[MakeshiftAudio 10+ year member]

http://www.southwire.com/voltagedropcalculator.jsp

Keep it under 3%, assume car wiring is direct underground. You will want a single phase configuration, and calculate voltage at about 14V or 13.8V, or whatever your batts sit at. General idea. This is to code and all. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[RetroAudioinc 5,000+ posts]

Hmmm got a question..

Solution:4 conductor(s) per phase utilizing a 1000 kcmil Copper conductor will limit the voltage drop to 0.93% or less when supplying 450 amps for 20 feet on a 14.4 volt system.

For Engineering Information:

* 545 Amps Rated ampacity of selected conductor

* 0.015 Ohms Resistance (Ohms per 1000 feet)

* 0.037 Ohms Reactance (Ohms per 1000 feet)

* 0.14 volts maximum allowable voltage drop at 1%

* 0.93 Actual voltage drop loss for each cable at 0.93%

* 0.53 volts Total maximum allowable parallel voltage drop loss for the circuit

* 0.9 Power Factor

Would that mean I need at least 4000 stand cable or I need 4 runs? Not clear on what 1000 kcmil is or means..

 

[RetroAudioinc 5,000+ posts]

I changed it back to 3% and got:

Solution:

2 conductor(s) per phase utilizing a 400 kcmil Copper conductor will limit the voltage drop to 2.95% or less when supplying 450 amps for 20 feet on a 14.4 volt system.

For Engineering Information:

* 335 Amps Rated ampacity of selected conductor

* 0.033 Ohms Resistance (Ohms per 1000 feet)

* 0.04 Ohms Reactance (Ohms per 1000 feet)

* 0.43 volts maximum allowable voltage drop at 3%

* 2.95 Actual voltage drop loss for each cable at 2.95%

* 0.85 volts Total maximum allowable parallel voltage drop loss for the circuit

* 0.9 Power Factor

 

[MakeshiftAudio 10+ year member]

kcmil stands for thousand circular mils. A cmil is one thousandth of an inch wide circle, and is used for cross sectional area.

Take a look here: http://en.wikipedia.org/wiki/American_Wire_Gauge

It says you need 2 runs of 400kcmil. That is the same as 3.7 runs of 4/0, so use 4 runs of 4/0, or 8 runs of 1/0. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Just to give a scale, 4/0 is .46" thick in dia, and has 212kcmil, while 1/0 is .3249 and has 106kcmil. xD

Strand count has nothing to do with current carrying capacity. that subject.

 

[Blue Fury 10+ year member]

bcae.com

 

[MakeshiftAudio 10+ year member]

USA Electrical Standards and Regulations, if you're saying I'm wrong and all. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

And, it's bcae1.com.