More paralleled conductors anyone?

[chris kennedy]

I have six runs of four 600's. Three runs will be 50' and three will be 46'. How can I figure the amperage difference for the two lenghts at 2000A.

So you don't have to open your books the resistance of 600 as per T8 is:

0.0214 ohm/kFT

Thanks people and I promise I'll write it down this time.

 

[don_resqcapt19]

Chris,
You can just do it as a percentage of the total length of all of the sets. In this case you have a total length of 288'. Now the tricky part. The percentage of current on the 46' length will equal the percentage of the 50' length. That will give you 17.36% of the total current or 347.2 amps on each of the 46' sets and 15.97% or 319.4 amps on each of the 50' sets. (based on a total current of 2000 amps)

 

[Smart $]

I have six runs of four 600's. Three runs will be 50' and three will be 46'. How can I figure the amperage difference for the two lenghts at 2000A.

So you don't have to open your books the resistance of 600 as per T8 is:

0.0214 ohm/kFT

Thanks people and I promise I'll write it down this time.

Previously posted.

3 ? 1/50' + 3 ? 1/46' = 0.125

2000 ? 1/50 ? 0.125 = 319.4
2000 ? 1/50 ? 0.125 = 319.4
2000 ? 1/50 ? 0.125 = 319.4
2000 ? 1/46 ? 0.125 = 347.2
2000 ? 1/46 ? 0.125 = 347.2
2000 ? 1/46 ? 0.125 = 347.2

Sum equals 2000.

 

[steve66]

With the current divider. Two resistors in parallel, R1 and R2. The current through R1 is

I1 = IT * R2/(R1+R2)

where IT is the total current.

It is easiest to lump the 3 50 runs together, and lump the 3 46 foot runs together. Assume R = the resistance per foot (we don't actually need the number you looked up.)

The the resistance of the (3) 46 foot runs is 46R/3. We will call that R1. And the 50 foot runs are 50R/3. We can call that R2.

So to find the current through the (3) 46 foot runs we have

I1= 2000 * (50R/3)/{ (50R/3)+(46R/3) }

Notice all the 3's cancel out, as do all the R's. That leaves:

I1= 2000 * 50/(50+46) = 1041 amps

So the current through each 46' run is 1041/3 (since it will divide equally between three equal lengths.)

Each 46' run = 347 amps

For the 50 foot runs, the current is (2000-1041)/3 = 319 amps.


Steve

 

[chris kennedy]

Thanks all and Don, I'm writing it down.:smile: