calculating max. distance from source to load at 480V

[k2panman]

How far can you run a 480V line to power a single phase 1500W .8pf load? I don't remember my transmission line theory - anyone know how to calculate this?

K2ofKeyLargo

 

[dpc]

That's only 4 amps at 480V single-phase (assuming you meant 480V and not 277V). If you make the wire big enough, you can run it a long way. How far do you need to go and what kind of load is it?

 

[k2panman]

A contractor is planning on running it about 1 mile. I don't know what the actual loading is yet - I don't have specs on the equipment yet, but it is a Dept. of Transportation camera and some microwave equipment to send the picture up the line back to headquaters - The power requirements I gave are just an estimate.

K2ofKeyLargo

 

[dpc]

Using the voltage drop tables in the Cutler-Hammer Specifying Guide (because I'm lazy), 4 amps in a mile of #6 copper for a single phase load yields about 18 volts drop.

 

[itsmoked]

480V camera...

 

[k2panman]

It is actually a 120V camera they say, but they think they can get 480V service run a mile then drop it down to 120V. With an inductive load and AC current, the calculation is not just a simple resistance calculation, is it?

K2ofKeyLargo

 

[cuky2000]

The enclose calculator could help you:

http://www.nexansenergy.com/egy/tecdoc/Corflex/index.html

To obtain the equivalent distance of 1 phase, 2wires, 480V, use the following trick:

System Type: 1 phase, 2 wires, 240V

Ampacity: 2 Amp _{1/2 the Ampacity at 480V (1500W/480V~4A)}

Power Factor: 80 %

Voltage drop limit: 3% or less

Distance: change it until desire results. Notice that the conductor size also change.

Imput other specific requirement, OH/UG, jacket, etc.