one ground rod or two

[olly]

On a residential house if you have the cold water pipe GEC do still need two ground rods over six feet apart? Or just one ground rod?

 

[rcarroll]

On a residential house if you have the cold water pipe GEC do still need two ground rods over six feet apart? Or just one ground rod?

2, unless you can prove 25 ohms or less. 250.53

 

[Lectricbota]

2, unless you can prove 25 ohms or less. 250.53

Really?I am still looking for my code book but IIRC that requirement is if ground rods are NOT supplemented by any other form of GEC.

 

[Gregg Harris]

(2) Supplemental Electrode Required. A single rod, pipe, or plate electrode shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(8). The supplemental electrode shall be permitted to be bonded to one of the following: Changed From 2008

?

250.53(A)(2): Added new requirement covering permitted bonding locations for supplemental electrodes.


(1)

Rod, pipe, or plate electrode

(2)

Grounding electrode conductor

(3)

Grounded service-entrance conductor

(4)

Nonflexible grounded service raceway

(5)

Any grounded service enclosure

Exception: If a single rod, pipe, or plate grounding electrode has a resistance to earth of 25 ohms or less, the supplemental electrode shall not be required.

 

[Gregg Harris]

(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(8). If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A). The supplemental electrode shall be bonded to one of the following: (1)

Grounding electrode conductor

(2)

Grounded service-entrance conductor

(3)

Nonflexible grounded service raceway

(4)

Any grounded service enclosure

(5)

As provided by 250.32(B)

Exception: The supplemental electrode shall be permitted to be bonded to the interior metal water piping at any convenient point as specified in 250.68(C)(1), Exception.

 

[junkhound]

ufer

ufer

Here, the very first thing the inspector asks on rough inspection is "do you have 2 ground rods" - and this is in wet Seattle area, they wnat 2 rods even if you show 25 ohm data (unless with a PE stamp).

My answer on most recent called inspection for a house (6 mo ago) was 'house has a concrete encased electrode', inspector was more than happy with that answer, better than 2 ground rods.

 

[rcarroll]

Really?I am still looking for my code book but IIRC that requirement is if ground rods are NOT supplemented by any other form of GEC.

My bad. I didn't read all of the section.:ashamed1: 1 rod required with water pipe ground.
1st. mistake of the day.

 

[rcarroll]

(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(8). If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A). QUOTE]250.53(A)(2) A single rod shall be supplemented by an addition electrode specified in 250.(A) 2 thru 8.A1 Water pipe. I guess 1 rod is ok. Yes?

 

[cowboyjwc]

(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(8). If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A). QUOTE]250.53(A)(2) A single rod shall be supplemented by an addition electrode specified in 250.(A) 2 thru 8.A1 Water pipe. I guess 1 rod is ok. Yes?

The took water pipe out in the 2011 code.

Look at (D)(2) and it says that water pipe shall be supplemented.