building steel as grounding electrode

[esc1234]

I am sure that this has been asked, but I searched to no avail. A new structure has been built, all steel framing. I am grounding my service to the buiding steel, also there is a water pipe available that meets all of the code requirements to be a grounding electrode. My question is will I meet code if I bond to buiding steel with a conductor, then jumper from building steel to the water pipe or do I need two seperate condustors, essentially creating a paralle path to ground? Thank you in advance.

 

[don_resqcapt19]

I am sure that this has been asked, but I searched to no avail. A new structure has been built, all steel framing. I am grounding my service to the buiding steel, also there is a water pipe available that meets all of the code requirements to be a grounding electrode. My question is will I meet code if I bond to buiding steel with a conductor, then jumper from building steel to the water pipe or do I need two seperate condustors, essentially creating a paralle path to ground? Thank you in advance.

You can bond them together, but there is no issue with parallel paths to multiple grounding electrodes. The only time multiple paths to the grounding electrodes would be a problem is if you made the grounding electrode conductor connection to multiple points on the grounded conductor.

 

[infinity]

A graphic from Mike Holt:

 

[augie47]

The only "catch" I can think of is that in order to do as you plan, the building steel must qualify as an electrode itself. Take a look at 250.52(A)(2).
In most cases, the steel automatically qualifies as an electrode (encase in concrete, etc) or can be made to qualify by connecting it to a ground rod, etc.

 

[pfalcon]

The only "catch" I can think of is that in order to do as you plan, the building steel must qualify as an electrode itself. Take a look at 250.52(A)(2).
In most cases, the steel automatically qualifies as an electrode (encase in concrete, etc) or can be made to qualify by connecting it to a ground rod, etc.

Connections between the steel members must also be checked. Pre-painted stuff can get you in trouble. You don't want to bond to a steel member that was accidently isolated.

 

[Smart $]

The only "catch" I can think of...

The one that bothers me in the Mike Holt Graphic posted by infinity is the means of extending the GES. I realize the graphic is from 2005, but under 2011, we can only use water pipe and structural steel electrodes to extend the GES.

(C) Metallic Water Pipe and Structural Metal. Ground-
ing electrode conductors and bonding jumpers shall be permitted
to be connected at the following locations and used
to extend the connection to an electrode(s):

(1) Interior metal water piping located not more than 1.52 m
(5 ft) from the point of entrance to the building shall be
permitted to be used as a conductor to interconnect electrodes
that are part of the grounding electrode system.

Exception: In industrial, commercial, and institutional
buildings or structures, if conditions of maintenance and
supervision ensure that only qualified persons service the
installation, interior metal water piping located more than
1.52 m (5 ft) from the point of entrance to the building shall
be permitted as a bonding conductor to interconnect electrodes
that are part of the grounding electrode system, or as
a grounding electrode conductor, if the entire length, other
than short sections passing perpendicularly through walls,
floors, or ceilings, of the interior metal water pipe that is
being used for the conductor is exposed.

(2) The structural frame of a building that is directly connected
to a grounding electrode as specified in
250.52(A)(2) or 250.68(C)(2)(a), (b), or (c) shall be
permitted as a bonding conductor to interconnect electrodes
that are part of the grounding electrode system,
or as a grounding electrode conductor.

a. By connecting the structural metal frame to the reinforcing
bars of a concrete-encased electrode, as
provided in 250.52(A)(3), or ground ring as provided
in 250.52(A)(4)
b. By bonding the structural metal frame to one or
more of the grounding electrodes, as specified in
250.52(A)(5) or (A)(7), that comply with (2)
c. By other approved means of establishing a connection
to earth​