how to determine amp loss when runninng 2000 ft wire?

Answer 1

Those references are fine, but you can both lose amps and volts. I understnd that if you have a constant current source driving the wire then you don't lose amps, but that is not the case.

YOu normally have a good voltage source like a utility feed driving the wire and load (say a light bulb). If you put the bulb at the end of 2000 ft of wire, then yes you will have lower voltage at the bulb compared to putting it right at the source. But all the resistance in teh wire and bulb add up - so you current is lower too!

For example - 120 VAC driving a load of 10 ohms would give 12 A. Now, say you have 2000 ft of wire that has 2 ohms of resistance. The current would now by only 10 A. The voltage at the load would be (10/12)*120 VAC = 100 VAC. SO you lose both amps and volts - don't know where these other guys got their EE degrees but I hope it wasn't anywhere I went.

Answer 2

You would not "lose" amps. amperes is the amount of charge (number of electrons) per second flowing through the wire. The same number going in will come out, if i read your question right. The longer the wire the higher the resistance and the fewer the electrons that can be pushed through the wire for a given voltage. So the same number exits as enters but a different number enters based on wire resistance. Your question is like asking how much water is lost in a 2000 foot pipe. None if the pipe doesn't leak but the amount of water you can push through the pipe depends on the pressure (voltage) and the resistance to flow in the pipe (pipe diameter and length).

Go to matweb.com and find resistivity of copper. Resistance = resistivity (wire material property) X length / cross section area. Then current = voltage across ends of wire / resistance.

Answer 3

You need to know what gauge (how big around or fat) the wire is first. That will tell you how much resistance per foot or meter or whatever length you need to calculate. What kind of conductor is important too, whether its copper or aluminum or whatever. Temperature can also be a factor but its small compared to the Resistance.

Here is a good site to help you get started. They have current carrying capabilities for most sizes of wire, and if you look at the chart, they have the resistance for the different sizes too. Then use Ohm's Law....

http://www.powerstream.com/Wire_Size.htm

you can also look at this site...they have examples of how to do the math...

http://www.paigewire.com/volt_loss_formulas.htm

Answer 4

You don't lose amps in a long wire, you lose volts. The amount of voltage drop depends on the amount of current you draw. Here's a calculator: