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 08-31-2006, 07:42 PM   #1
Member
 
Join Date: Mar 2006
Posts: 46
Share |
Default

2 ground rods???


Well I had the inspector out today for my sub panel that Im putting in my garage. I wanted to get the trench inspected so I could back fill.

Anyways, he wants me to use (2) 5/8 by 8ft ground rods, spaced a min of 6 ft apart. I never heard of using 2 ground rods before.

stagger19 is offline   Reply With Quote
Old 08-31-2006, 07:50 PM   #2
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,772
Default

2 ground rods???


Unless it is a local ammendmant, he cannot demand two rods.

But.......what he can do is ask for the test results from checking the ground resistance to see if the one rod measured within specs; 25Ω or less. This is NOT a test you can do with any old meter either. It requires an $800 ground resistance meter.

This is why most of us simply sink two rods and are done with it.

__________________
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. If you're on the '14 already I feel sorry for you.
Speedy Petey is offline   Reply With Quote
Old 09-02-2006, 07:57 AM   #3
Newbie
 
Join Date: Aug 2006
Posts: 5
Default

2 ground rods???


We rewired our house in 1999 and setup a panel for electric heat. We had to install two grounding rods for the new service. We are in PA. and the national code required it.
rforsha is offline   Reply With Quote
Old 09-02-2006, 09:25 AM   #4
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,772
Default

2 ground rods???


The national code (NEC) does NOT require two rods.

See my second paragraph above, or NEC 250.56

Actually here it is:

250.56 Resistance of Rod, Pipe, and Plate Electrodes
A single electrode consisting of a rod, pipe, or plate that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode of any of the types specified by 250.52(A)(2) through (A)(7). Where multiple rod, pipe, or plate electrodes are installed to meet the requirements of this section, they shall not be less than 1.8 m (6 ft) apart.
__________________
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. If you're on the '14 already I feel sorry for you.
Speedy Petey is offline   Reply With Quote
Old 09-02-2006, 11:44 AM   #5
General Contractor
 
Join Date: Sep 2006
Location: Illinois
Posts: 37
Default

2 ground rods???


Sometimes it is best to do what the inspector asks. Inspectors municipal employees or private contractors usually are certified by the ICC, (International Code Commission). They have to at least pass 1 test to get this certification. However their background of experience and knowledge is usually not as much as a seasoned veteran.

So they might require a little extra to cover their own tracks.(so to say) After all a lot of contractors and craftsman say code is only the minimum you should do. After all, how could an extra ground rod hurt you? Except maybe $25 for material. Like the shoe company says "Just Do It"
fqp25 is offline   Reply With Quote
Old 09-02-2006, 01:30 PM   #6
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,772
Default

2 ground rods???


Quote:
Originally Posted by fqp25
After all, how could an extra ground rod hurt you?
Once you've had to sink a few extra rods in rocky soil you'll know how they can hurt.

Confidentially: I use a rotary hammer with a drive attachment.
__________________
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. If you're on the '14 already I feel sorry for you.
Speedy Petey is offline   Reply With Quote
Old 09-05-2006, 03:08 PM   #7
Newbie
 
Join Date: Sep 2006
Posts: 9
Default

2 ground rods???


you need two ground rods here in NY also an extra can't hurt
HUDSONVALLEYEXT is offline   Reply With Quote
Old 09-05-2006, 03:48 PM   #8
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,772
Default

2 ground rods???


Two are ONLY required if the resistance is not met. See post #4.

Or if the POCO requires it. Such as with a pedestal service. Then it is a POCO issue and not an NEC or local building code issue.
__________________
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. If you're on the '14 already I feel sorry for you.
Speedy Petey is offline   Reply With Quote
Old 02-07-2012, 03:54 PM   #9
Newbie
 
Join Date: Feb 2012
Posts: 1
Default

2 ground rods???


The reason that some inspectors require 2, is that they dont want to meggar it, or they dont have the equipment, Most of the time when they require 2 ground rods its because you used aluminum wire.
buckeyefanted is offline   Reply With Quote
Old 02-07-2012, 04:29 PM   #10
Electrical Contractor
 
rrolleston's Avatar
 
Join Date: Oct 2011
Location: Granville, NY
Posts: 1,941
Send a message via AIM to rrolleston Send a message via Yahoo to rrolleston
Default

2 ground rods???


Around here they require the same. Two rods at least six feet apart with #4 wire running from the panel to both rods then back to the panel. For what it costs it's not worth arguing with them.
rrolleston is offline   Reply With Quote
Old 02-07-2012, 05:56 PM   #11
Member
 
concretemasonry's Avatar
 
Join Date: Oct 2006
Location: Minneapolis/St. Paul, Minnesota - Latitude 45.057 Longitude -93.074
Posts: 3,695
Default

2 ground rods???


Local jurisdictions can always over-ride the national MINIMUM codes in any area of construction and permitting. This is based on the concept that the national standard is just a MINIMUM and there may be local natural (climate, soil, moisture, factors) conditions that justify it based on experience and performance.

the cost differences are minimal compared to the long term safety.

Dick
concretemasonry is offline   Reply With Quote
Old 02-07-2012, 06:26 PM   #12
Electrical Contractor
 
rrolleston's Avatar
 
Join Date: Oct 2011
Location: Granville, NY
Posts: 1,941
Send a message via AIM to rrolleston Send a message via Yahoo to rrolleston
Default

2 ground rods???


Probably due to the really sandy soil. During the dry months you could dig really far down and never see any moist ground.
rrolleston is offline   Reply With Quote
Old 02-07-2012, 06:48 PM   #13
Member
 
Join Date: Dec 2011
Location: Michigan
Posts: 843
Default

2 ground rods???


Quote:
Originally Posted by Speedy Petey View Post
Two are ONLY required if the resistance is not met. See post #4.

Or if the POCO requires it. Such as with a pedestal service. Then it is a POCO issue and not an NEC or local building code issue.
Ground rods on a sub panel???
What about ground loop???
Hardway is offline   Reply With Quote
Old 02-07-2012, 07:05 PM   #14
Electrical Contractor
 
rrolleston's Avatar
 
Join Date: Oct 2011
Location: Granville, NY
Posts: 1,941
Send a message via AIM to rrolleston Send a message via Yahoo to rrolleston
Default

2 ground rods???


Quote:
Originally Posted by Speedy Petey View Post
Once you've had to sink a few extra rods in rocky soil you'll know how they can hurt.

Confidentially: I use a rotary hammer with a drive attachment.

LOL. Watched a few videos of them those are really nice.
rrolleston is offline   Reply With Quote
Old 02-07-2012, 07:15 PM   #15
Member
 
Join Date: Dec 2011
Location: Michigan
Posts: 843
Default

2 ground rods???


Quote:
Originally Posted by stagger19 View Post
Well I had the inspector out today for my sub panel that Im putting in my garage. I wanted to get the trench inspected so I could back fill.

Anyways, he wants me to use (2) 5/8 by 8ft ground rods, spaced a min of 6 ft apart. I never heard of using 2 ground rods before.
Are you feeding this sub panel from the house main?

Hardway 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.