ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Where is Everyone?
by gfretwell - 04/09/21 01:08 AM
HI gang, long time since I was here...
by gfretwell - 04/09/21 01:02 AM
Lock-down Thread
by gfretwell - 04/06/21 09:30 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
1 registered members (Scott35), 8 guests, and 18 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
burial depth - GEC #9787 05/13/02 09:40 PM
Joined: Jun 2001
Posts: 141
amp-man Offline OP
Hi y'all,

A simple question:

When using 4 AWG (copper, stranded) as a grounding electrode conductor, what burial depth is required? This is for a residential occupancy.

Is it 24 inches, based on column 1 (direct burial cables or conductors) and the first row ("all locations not specified below") (the table is for "0 to 600 volts")?

Would appreciate your views.


Work Gear for Electricians and the Trades
Re: burial depth - GEC #9788 05/18/02 10:07 AM
Joined: Jul 2001
Posts: 311
Frank Cinker Offline
Good question. I've never even thought of it before. I couldn't imagine a GEC being buried 24 inches. For example, if a driven ground rod is located several feet from a house I usually buried the GEC 6 inches if not less at times. Perhaps an electrical inspector can address this question.

[This message has been edited by Frank Cinker (edited 05-18-2002).]

Re: burial depth - GEC #9789 05/18/02 10:43 AM
Joined: Nov 2000
Posts: 2,236
sparky66wv Offline
Yes, very good Q!

Didn't want to ask it myself, because I was afraid of what the answer would be!

Residential/Commercial Inspector
5 Star Inspections
Member IAEI
Re: burial depth - GEC #9790 05/18/02 12:19 PM
Joined: Nov 2001
Posts: 280
motor-T Offline
Why would you use No.4 to a ground rod ?
...And would it not be No.4 to the water line if one exists?
As far as burial goes it must be below the earth, is there a depth for it after all it must come out of the ground to go to the meter base or service panel.


Re: burial depth - GEC #9791 05/18/02 12:39 PM
Joined: Feb 2002
Posts: 182
Bob Offline
I you are considering using the #4 as a
Ground Electrode, section 250-52 (99) will
require 24"

Re: burial depth - GEC #9792 05/18/02 01:28 PM
Joined: Nov 2000
Posts: 2,236
sparky66wv Offline
I use #4 bare solid Cu because no conduit is required.... Uh, right?

#6 isn't significantly cheaper, and #4 just seems to be the tradition for 200A services... Any better arguments either way?

[Linked Image]

Residential/Commercial Inspector
5 Star Inspections
Member IAEI
Re: burial depth - GEC #9793 05/18/02 02:15 PM
Joined: Nov 2001
Posts: 280
motor-T Offline
(A) Connections to Rod, Pipe, or Plate Electrodes. Where the grounding electrode conductor is connected to rod, pipe, or plate electrodes as permitted in 250.52(A)(5) or 250.52(A)(6), that portion of the conductor that is the sole connection to the grounding electrode shall not be required to be larger than 6 AWG copper wire or 4 AWG aluminum wire.

My understanding of this is that the resistance of the ground rod itself is higher than the no.4 it self and would not improve the resistance of the system.

Re: burial depth - GEC #9794 05/19/02 09:36 AM
Joined: Apr 2002
Posts: 914
Electric Eagle Offline
Mark, You're right about #4 being larger than required, but I know in my area you can't pass inspection with #6 on a 200 amp system so we just automatically use #4 solid CU.

Re: burial depth - GEC #9795 05/19/02 11:58 AM
Joined: Jan 2001
Posts: 1,044
Tom Offline
When I inspect service entrances in the Allegheny Power service area, I'll accept just about any depth that will cover the conductor & won't get washed away by the rain.

What most guys do is about 1 shovel in depth, about 6 inches.

It could be a judgement call about using #6, since it is only allowed where it is "free from exposure to physical damage." Whereas #4 can be used with no protection if it is not "exposed to severe physical damage."

I've seen some make an arguement for burial at 24" based on column 1 of Table 300.5 After all, this is a conductor, and it operates within the 0-600 volt parameters of the table. If I'm ever forced into burying the grounding electrode conductor that deep, I'll sub out that phase of the work, too much shovel time.

Few things are harder to put up with than the annoyance of a good example.
Re: burial depth - GEC #9796 05/19/02 12:53 PM
Joined: Nov 2001
Posts: 280
motor-T Offline
I see where you and Sparky66wv bboth use no.4 solid, I have never used solid for fear of getting 'un-removable' kinks in it so I always use stranded. Now I can understand the following the contour of the building better wiht solid, is this why ? But what about going to the water line ? A lot of the times I have to go across a basement wiht the cable to get to the water-meter do you use solid for this and how does it work out for you.???
I will try anything if it helps the job run smoother, alot of time i will mount some 1/2 pvc on the side of the basement wall and drop the no.6 to the ground-rods that way if it helps protect it on a long run, but generally if I can I will drill a hole close to the dirt level and snake the ground wire out that way, then plug it up with 'Duck' seal.

Page 1 of 2 1 2


2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman


Member Spotlight
Montreal, Quebec, Canada
Posts: 28
Joined: March 2011
Show All Member Profiles 
Top Posters(30 Days)
BigB 1
Popular Topics(Views)
277,639 Are you busy
211,271 Re: Forum
198,304 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3