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GEC

Merry Christmas
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Little Bill said:
That's not the way I'm reading it. It says if the pipe, rod, or plate meets the 25 ohm, then no additional electrode needed. So if the pipe didn't meet it, then a rod added would satisfy that. It doesn't say a single rod is not an electrode.
One pipe + one rod = satisfied

(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:
(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.
Click to expand...
That is the very reason that I submitted a PI to change "pipe" to "driven pipe". The "pipe" in that section has nothing to do with a metal underground water pipe.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Little Bill said:
Because it's just going to be replaced with PEX or the like!
Click to expand...
There are two trains of thought as I see it:

1. Does the inspector have to prove that it qualifies as an electrode to require bonding?

Or:

2. Does the electrician have to prove that it does not qualify as an electrode to omit it?
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
ggunn said:
Some AHJs require a grounding bond to a cold water pipe regardless of any other GEC connection.
Click to expand...
If the water piping system is all metallic it is required to be bonded to the electrical system even if it doesn't qualify as an electrode.
 
Fred B

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Historically around here all you had is the water pipe (galvanized) as the sole GE. Then came requirement that it must be supplemented by another electrode (rod or otherwise). Now with so much plastic piping being changed to replace the Galvanized it can be questioned whether you have an electrode from the water pipe. (regardless metal water pipe still must be bonded but it Might not qualify as an electrode 250.52(A)(1)
(1) Metal Underground Water Pipe.
A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed.

If it doesn't meet this criteria then you don't have an electrode and the one rod 250.52(A)(5) must be supplemented by another Electrode. (250.53(A)(2)). If the water pipe meets the requirement then that electrode must be supplemented by another electrode. (250.53(D)(2)).

250.52(A)(1) water pipe and 250.52(A)(5) Rod and pipe electrode are not the same thing. 250.52(A)(1) requires 10 ft in continuous earth contact, 250.52(A)(5) require 8 ft in length.

One water pipe meeting 250.52(A)(2) and one Rod Meeting 250.53(D)(2) are all that is required.

250.52(A)(4) a single rod 8 ft in length is a GE
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Fred B said:
One water pipe meeting 250.52(A)(2) and one Rod Meeting 250.53(D)(2) are all that is required.
Click to expand...
OK, but a ground rod meeting 250.53(D)(2) will have its own supplemental electrode, typically a 2nd ground rod, as the water pipe electrode does not satisfy 250.53(D)(2).

So one water pipe and two rods are all that is required.

Cheers, Wayne
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Djelite said:
Again in nyc 5 ft in before any coupling
Click to expand...
The NEC allows the connection within 5' of the entry of the water pipe into the structure. There is no prohibition on couplings, valves, water meters, etc. being within that 5' The only NYC amendment to Article 250 is the exception to 250.52(A)(1) and that wouldn't apply to couplings in the first 5' of water pipe. So what is the source of your statement?
 
D

Djelite

Senior Member
Location
Ny
Occupation
Electrician
infinity said:
The NEC allows the connection within 5' of the entry of the water pipe into the structure. There is no prohibition on couplings, valves, water meters, etc. being within that 5' The only NYC amendment to Article 250 is the exception to 250.52(A)(1) and that wouldn't apply to couplings in the first 5' of water pipe. So what is the source of your statementdob requirements
Click to expand...
infinity said:
The NEC allows the connection within 5' of the entry of the water pipe into the structure. There is no prohibition on couplings, valves, water meters, etc. being within that 5' The only NYC amendment to Article 250 is the exception to 250.52(A)(1) and that wouldn't apply to couplings in the first 5' of water pipe. So what is the source of your statement?
Click to expand...
Dob
 
Fred B

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
wwhitney said:
OK, but a ground rod meeting 250.53(D)(2) will have its own supplemental electrode, typically a 2nd ground rod, as the water pipe electrode does not satisfy 250.53(D)(2).

So one water pipe and two rods are all that is required.

Cheers, Wayne
Click to expand...
So you are saying to supplement the supplement. So wording of 250.53(D) should be change to read supplemented by 2 Rods.
 
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