Country Living
Country Living, Country Skills
Country People - A Country Living Resource and Community
Message Board
Country Topics
Trading Post
Memory Lane
Country Skills
Country Cooking

The Kitchen

Photo Gallery
Vintage Photos
Special Collections

Country Humor
Country Sounds
Coloring Book
Interactive Story

Farm Tractors
Tractor Parts
Tractor Manuals

Classic Trucks
Antique Tractors
Modern Tractors
Site Map
Links Page
Contact Us

Country Talk Discussion Board

Re: 230' of electrical

[ Expand ] [ View Follow Ups ] [ Post Followup ] [ Return to Forum ]

Posted by basod on February 19, 2004 at 22:17:25 from (

In Reply to: 230' of electrical posted by Chris Mainka on February 08, 2004 at 14:28:40:

If you want to find out what cable to use and don't have the fancy calculator its relatively simple calculations. Every conductor has a resistance (R) usually measured in ohms/100ft. I use my Ugly's electrical reference book to find the resistance but NEC may publish something online, or electrical supplier can provide you with it. Getting to the math though, the principle resides in the sum of the rises equals the sum of the drops (goes ins=goes outs). I'd guess you're running a 220volt supply w/70amp main. To make it easy we'll say you're conductor has 0.2ohms resistance/100ft. Ohm's Law V=I*R the voltage drop for 230ft is 230ft/100ft=2.3, 2.3*0.2ohms=0.46ohms of resistance. Then 70A*0.46=32.2volts, so you'll have a voltage drop of 32.2 volts over the run resulting in a terminal voltage of supply-drop.or
220-32.2=187.8V and to find what your equivalent nominal 120V rating would be (one hot and the nuetral) divide the 220V rating by the sqaure root of 3 or 1.732 so for a true 220V circuit 220/1.732= 127V or in the case of the 230Ft run 187.8/1.732=108V It'll make your lights burn a little dimmer but horsepower rating on motors are reduced and welders will try to draw more current to achieve the same Kw output resulting in frequenlty tripped breakers.

Follow Ups:

Post A Followup


Subject: Re: Re: 230' of electrical


Optional Link URL:
Link Title:
Optional Image URL:

Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

[Home] [Search]

Copyright © 1999-2013
All Rights Reserved
A Country Living Resource and Community