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 05-02-2007, 07:23 PM   #1
Extreme DIY'r Adk's, NY
 
Join Date: Nov 2005
Posts: 293
Rewards Points: 250
Default

ground loops


Can someone explain "ground loops and their proper use and placement?" ...and how they apply to sub panels, and outbuildings in the following example:

A 200a main breaker panel in house, feeds a 150a sub main lug panel in house via 4 conductor from a double 100 (bus oversized). A double pole 100 in that sub main lug then feeds to an outbuilding via 4 conductor. I read that NEC says the outbuilding should also have its own grounding rod but local electricians all say it should not and there should be a ground loop back at the house.

TIA

crecore is offline   Reply With Quote
Old 05-02-2007, 09:08 PM   #2
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,858
Rewards Points: 2,020
Default

ground loops


If all the electricians you know are saying an out-building with a sub-panel does not require a ground rod you need to find new electricians.

A detached structure most certainly DOES require some form of grounding electrode. This is regardless if it is fed by a 3-wire or 4-wire feeder.
I think what the guys you know are saying is that you should use a 4-wire feeder which has a grounding conductor run with the feeder conductors. This is not a ground loop though.
Most times a 4-wire feeder is required by code.

A ground loop is something you DO NOT want. The point is that if there is a compromise on the neutral conductor the ground does not carry any load current.

__________________
Sometimes I feel like if I answer any more questions it is like someone trying to climb over a fence to jump off a bridge and me giving them a boost.
Answers based on the 2008 & 2011 NEC.
Speedy Petey 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
12v diff between ground and neutral at panel am9518 Electrical 7 02-25-2008 06:28 PM
Subpanel feeder questions Silhanek Electrical 4 03-22-2007 06:30 PM
Electrical ground redline Electrical 12 06-27-2006 07:09 PM
Ground Wire Problem ScubaRaven Electrical 11 06-08-2006 02:32 PM
Proper ground with plastic boxes tjandt Electrical 3 11-07-2005 08:16 AM




Top of Page | View New Posts

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