ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
0 members (), 265 guests, and 15 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Feb 2008
Posts: 12
T
theseus Offline OP
Member
IEC 60364-4-41-2005

411.5 TT system
411.5.1 All exposed-conductive-parts collectively protected by the same protective device
shall be connected by the protective conductors to an earth electrode common to all those
parts. Where several protective devices are utilized in series, this requirement applies
separately to all the exposed-conductive-parts protected by each device.

What would happen if exposed-conductive-parts collectively protected by the same protective device be connected to different earth electrode?

Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
You will see "ground shift" between them. "Earth" is not "zero volts" and you can see differences between ground rods that are surprisingly close together. That is why we always bond all the electrodes in a system.


Greg Fretwell
Joined: Jul 2002
Posts: 8,443
Likes: 3
Member
Greg,
I agree with the ground shift thing.
IMO, you are wasting time and materials installing Earth Electrodes any closer than about 12' apart.

One thing I have had good results with in the past, is instead of actually driving a second electrode, is clamping some stripped heavy copper wire to the electrode and burying that copper in a long thin trench at about 2' deep, this has bought down the actual earth electrode resistance and hence increased it's current-carrying capacity under fault current conditions.


Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5