Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 02-01-2011, 09:10 AM   #1
Newbie
 
Join Date: Feb 2011
Posts: 15
Share |
Default

Long Run Voltage Drop


I want to keep the voltage drop within acceptable limits on a long feeder run. 240v Single Phase @ 200amps for 500' underground. The lugs at each end can accommodate 4/0 max. Can I connect 4/0 at each end and then have 500 mcm for the majority of the run?
Attached Thumbnails
Long Run Voltage Drop-500mcm.jpg  

i_need_help is offline   Reply With Quote
Old 02-01-2011, 09:26 AM   #2
Master Electrician
 
Join Date: Mar 2010
Location: Indiana
Posts: 2,787
Default

Long Run Voltage Drop


Provided they are available in the sizes you need, you could use pin terminals to reduce the 500 to 4/0. A Burndy AYP500 will terminate to 500MCM and provide a pin .68 inch in diameter. You will need the proper compression tool to install these connectors. Some electrical supply house will loan you the tool when you purchase the terminals.





Last edited by brric; 02-01-2011 at 09:59 AM.
brric is online now   Reply With Quote
The Following User Says Thank You to brric For This Useful Post:
i_need_help (02-01-2011)
Old 02-01-2011, 10:24 AM   #3
Member
 
Join Date: Aug 2010
Posts: 440
Default

Long Run Voltage Drop


250mcm will give you 4.9% drop or 10 volts.
oleguy74 is offline   Reply With Quote
The Following User Says Thank You to oleguy74 For This Useful Post:
i_need_help (02-01-2011)
Old 02-01-2011, 11:00 AM   #4
Member
 
Join Date: Jun 2007
Posts: 3,503
Default

Long Run Voltage Drop


http://www.liteco.ca/Portals/_Rainbo...calculator.htm
J. V. is offline   Reply With Quote
Old 02-01-2011, 11:08 AM   #5
Member
 
Sfeyelectric's Avatar
 
Join Date: Dec 2010
Posts: 105
Default

Long Run Voltage Drop


Quote:
Originally Posted by oleguy74 View Post
250mcm will give you 4.9% drop or 10 volts.
Yes but that is above the 3% or 7.2volts that are acceptable
Sfeyelectric is offline   Reply With Quote
Old 02-01-2011, 11:19 AM   #6
Member
 
Join Date: Aug 2010
Posts: 440
Default

Long Run Voltage Drop


then go 350kcm.that is 3%.i would do a cost check.
oleguy74 is offline   Reply With Quote
Old 02-04-2011, 07:27 PM   #7
Member
 
Join Date: Feb 2011
Location: Manitoba, Canada
Posts: 127
Default

Long Run Voltage Drop


Quote:
Originally Posted by oleguy74 View Post
then go 350kcm.that is 3%.i would do a cost check.
You said feeder circuit right? Are you talking from the pole, throught your meter to the panel? If so, you can only have 2% VD
CheapCharlie is offline   Reply With Quote
Old 02-04-2011, 10:45 PM   #8
Electrical Supplier
 
Join Date: Jun 2010
Location: Dayton, OH
Posts: 205
Default

Long Run Voltage Drop


Branch circuits are maximum of 5%, preferably 3%.....DC is maximum of 3%

Even if he uses 250 or 350 his lugs still arent big enough.........You can just bring the 500 mcm into a "tangle box" such as a 8x8x6 PVC box and make junctions inside with splicers or split bolts.....tape em up and you are good......

as long as your overcurrent device is rated, i dont see why not.
__________________
"Do it right the first time and avoid duplication of effort"

Your AHJ/Inspectors ALWAYS have the final say on ANY electrical code issue.
If in doubt, contact a licensed, experienced, reputable electrician to perform the work.
LyonsElecSupply is offline   Reply With Quote
Old 02-05-2011, 07:16 AM   #9
Electrician
 
SD515's Avatar
 
Join Date: Aug 2008
Location: Near Jackson Michigan Area
Posts: 1,450
Default

Long Run Voltage Drop


I'd hate to be the one having to make joints with 500 MCM in a 8X8 box. One maybe...but 4? Not my idea of fun...
__________________
Kyle

Just because you can, doesn't always mean you should
SD515 is offline   Reply With Quote
Old 02-05-2011, 07:56 AM   #10
Member
 
Join Date: Feb 2011
Location: Manitoba, Canada
Posts: 127
Default

Long Run Voltage Drop


I realized the OP is from the states. Here in canada FYI the VD allowable is 5% from meter to end of branch circuit. No more than 3% from your main to the end of a branch circuit. That's to say if you only have 1% from your meter to the panel, it doesn't mean you can have 4% on a branch circuit. I hope that makes sense
CheapCharlie is offline   Reply With Quote
Old 02-05-2011, 10:53 AM   #11
Electrical Supplier
 
Join Date: Jun 2010
Location: Dayton, OH
Posts: 205
Default

Long Run Voltage Drop


Obviously you would have to do a cubic inch calculation for the used wires. I was making a suggestion using an example. Common sense dictates you would use a bigger box if it didnt fit.

FYI: to the OP, you can reduce your neutral down, I *think* 70% of the rated capacity of the OCPD. Also you can reduce your ground. I would say a 4/0 ground is fine. Grounds are not Current carrying so you dont have to worry as much about ampere rating.

Note: i do not have the code in front of me, but if i remember right there is a provision for reducing the neutral in feeder circuits.

Also OP, why do you HAVE TO HAVE this capacity? im guessing 200A......Derating and biting the bullet may be in your best interest.

__________________
"Do it right the first time and avoid duplication of effort"

Your AHJ/Inspectors ALWAYS have the final say on ANY electrical code issue.
If in doubt, contact a licensed, experienced, reputable electrician to perform the work.
LyonsElecSupply is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Phantom voltage -- I'm completely stumped kb01 Electrical 2 12-24-2010 06:44 PM
Could I move my Meter & Power Drop to the Side of my house? jamiedolan Electrical 9 07-28-2010 05:16 PM
Wire sizing to the condensor zootjeff HVAC 9 06-22-2009 08:02 AM
Voltage drop fix I discovered... rgsgww Electrical 12 12-09-2008 05:21 PM
2 - 900w tansformers on a 15A circuit? tonyBagadonuts Electrical 19 07-20-2008 07:15 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.