The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Correct rotation, wrong sequence
by Potseal
Today at 03:14 PM
Industrail Control Panel bonding per 409.108
by sparkyinak
Yesterday at 06:29 PM
Calling all Non-US members!! (Non-US only)
by aussie240
12/07/16 02:39 AM
Photo Upload Tutorial
by DanK
12/06/16 11:35 PM
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 12
HotLine1 10
Potseal 9
sparkyinak 8
Texas_Ranger 7
Who's Online
1 registered (cableguy619), 212 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 3 1 2 3 >
Topic Options
Rate This Topic
#23866 - 03/29/03 01:51 PM Grond rod questions
Electricmanscott Offline
Member

Registered: 01/12/02
Posts: 1478
Loc: Holden, MA USA
Installing a service in an old barn today. Could not get the ground rods in. (bedrock?) Instead I laid them in the trench that the service is run in. It is about three feet deep. I used three rods, each one six feet from the other. Reading through the handbook I am not to clear on this exact situation. Appreciate all thoughts.

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#23867 - 03/29/03 03:39 PM Re: Grond rod questions
Fred Offline
Member

Registered: 04/30/01
Posts: 461
Loc: Straughn, IN 47387
Scott. According to 250.53(G) you've satisfied the NEC providing the trench you put them in was at least 30" deep. Sounds like you did the best anyone could do and then some.

Top
#23868 - 03/29/03 04:41 PM Re: Grond rod questions
zapped208 Offline
Member

Registered: 02/18/03
Posts: 201
Loc: Somewhere in USA
20' of #4 bare copper would be acceptable in the ditch too, if your AHJ has no problems with that.
_________________________
Shoot first, apologize later.....maybe

Top
#23869 - 03/29/03 05:21 PM Re: Grond rod questions
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
Zapped,
Please cite the code section that permits the use of 20' of #4 in a ditch as a grounding electrode.
Don
_________________________
Don(resqcapt19)

Top
#23870 - 03/29/03 06:20 PM Re: Grond rod questions
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
We do this sort of thing all the time in New Zealand, especially where a really good Earth is required, we lay out about 20-30 metres of 35-50mm2, for really poor soils and it works a treat.
This sort of system is really only used for Earthing Distribution Transformers and the like, no one would like a bill for this sort of wire at these lengths.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

Top
#23871 - 03/29/03 06:51 PM Re: Grond rod questions
zapped208 Offline
Member

Registered: 02/18/03
Posts: 201
Loc: Somewhere in USA
Don,- While there is no direct code section stating we can install the electrode system as I said, there also is no wording that says I cannot. Basicly we are using 250.52(A3&4) without the concrete. On our larger services we use 2,3,&4/0 copper. Our AHJ's have no problems with these installations. Don't get me wrong, I do use ground rods 90% of the time.
_________________________
Shoot first, apologize later.....maybe

Top
#23872 - 03/29/03 07:57 PM Re: Grond rod questions
DBC1 Offline
Member

Registered: 03/15/03
Posts: 18
Loc: Tulsa, OK USA
Scott, what you did will satisfy code. Another option would have been to use a ground ring or plate electrode.

Top
#23873 - 03/29/03 08:06 PM Re: Grond rod questions
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
zapped,
There is wording that says you can't do that. The code lists the grounding electrodes that are permitted to be used in 250.52. Installing 20' of bare copper in a ditch is not on the list, unless the 20' encircles a building. I see no reason why it shouldn't be just as good as a ground ring, but it is not permitted by the NEC rules.
_________________________
Don(resqcapt19)

Top
#23874 - 03/29/03 08:47 PM Re: Grond rod questions
frenchelectrican Offline

Member

Registered: 02/06/03
Posts: 938
Loc: Wi/ Paris France { France for ...
don :

i hate to ask you a stupid question but i know i will respect you with this one anyway but you mean that cant bury bare copper wire unless it is around the building that mean all the way around the building area ???
( i never done this one so i am double checking i did see it on nec code say cant bury it in short straght section ..)


thanks for your time


merci marc
_________________________
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)


Top
#23875 - 03/29/03 08:55 PM Re: Grond rod questions
zapped208 Offline
Member

Registered: 02/18/03
Posts: 201
Loc: Somewhere in USA
Don,- Maybe the CMP should take a closer look at 250.52(A4), kinda hard to take 20' of wire and encircle a 25+ 40' building.
_________________________
Shoot first, apologize later.....maybe

Top
Page 1 of 3 1 2 3 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals