M.D., the entire point of the change in 250.50 from the 2002 to the 2005 was to require the Ufer to be used in new construction. Johnston's proposal was initially rejected on the grounds that it would require chipping the concrete out on old houses, houses built prior to the 2005 coming into effect.
Johnston's defense of the proposal when it was rejected (as a fellow CMP member in dissent):
JOHNSTON: The panel statement is directed to existing installations. It is understood that this requirement is not feasible for existing installations and the intent of this proposal was not directed in any way to existing installations. Generally, the Code is not retroactive.
The word available as used in this section is creating inconsistencies in the field relative to which grounding electrodes are required to be used in electrical installations. The concrete encased grounding electrode is a proven effective electrode and is inherent to the construction of most buildings or structures and should be included in the grounding electrode system as such. The NEC style manual recommends not using the word "available" to avoid this very type of inconsistency in application and enforcement Code rules.
The comment on affirmative (the statement supporting the rejection) even made it clear that new installations, installations without a C.O., would benefit from the strengthened wording, but as worded it would require chipping of concrete on a 50 year old house.
Comment on Affirmative:
BOKSINER: While the proposed requirement is not feasible for existing installations where all the electrodes are not available, it is feasible and desirable for new installations. The words "if available" should be changed to "if available in existing installations or if present on new installations." There is precedent in the NEC for a distinction between new and existing installations.
Come ROC time, Johnston submitted a comment, it was accepted, and entered the 2005 code.
Johnston said:
Substantiation: For clarification, it was not intended that this proposed change to this section cause the rule to be applied to existing buildings or buildings with existing footings. This revision would remove the word “available” from a mandatory requirement and be consistent with the Style Manual direction that encourages the word “available” be avoided. The section as previously worded left a lot of questions as to what the requirement of the section really is providing.
If effective electrodes are inherent to building construction, it should be clear that all such electrodes should make up the grounding electrode system and be used. It is also a style manual recommendation to avoid
the word “available” in mandatory Code rules. The revision should help clarify what is intended relative to the grounding electrode system for buildings or structures.
They agreed, and used Johnston's proposal in concert with Cartal's comment/suggestion:
________________________________________________________________
5-81 Log #1365 NEC-P05 Final Action: Accept in Principle
( 250.50 Exception )
________________________________________________________________
Submitter: Andre R. Cartal, Princeton Borough Building Dept.
Comment on Proposal No: 5-115
Recommendation: The Panel should accept this proposal with the following Exception:
Exception: Concrete-encased electrodes in footings of existing buildings shall not be required to be part of the grounding electrode system.
Substantiation: The words “if available” has prevented the use of a proven grounding electrode for too many years. These words have no place in the NEC. From the inspector's viewpoint, it presents a no-win enforcement problem.
The removal of these words will require electrical design professionals to specify and also enforce compliance with 250.50.
Panel Meeting Action: Accept in Principle
Revise 250.50 to read as follows:
“250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system. Where none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.
Exception: Concrete-encased electrodes of existing buildings or structures shall not be required to be part of the grounding electrode system where the steel reinforcing bars or rods are not accessible for use without disturbing the concrete.”
Panel Statement: Implementation of requirements proposed in 5-115 is not feasible for all installations. An exception is needed to prevent situations where concrete would be required to be disturbed. Additional editorial changes were made to improve clarity.
Number Eligible to Vote: 16
Ballot Results: Affirmative: 16
Comment on Affirmative:
ROBERTSON: I am voting in the affirmative, however, I would like to make a comment on this one.
I agree with the substantiation that the words “if available” have prevented the use of a proven electrode for too many years. By removing the words “if available” and replacing with the proposed text will now mean the Authority Having Jurisdiction will need to be aware of the sequence of construction and the reality that in a lot of cases the concrete encased electrode is, in fact, not available by the time the decision is made on which electrical contractor will be doing the project.
It will now become the responsibility of the Authority Having Jurisdiction to make sure these electrodes are made available for use prior to the concrete being poured in the foundations.
On far too many projects the foundations, spread beams, piers and grade beams are poured prior to awarding the electrical work on a project. This concern should not be a factor in making the change, it will however, require some changes in the timing of when electrical contracts are awarded in some areas.
Electrical contractors will need to keep this in mind when accepting projects.
M. D., the panel has laid out in no uncertain terms, especially in light of Robertson's statement, that a new building with a new cured footer with a Ufer in it had better be connected to the GES, or somebody would be chipping concrete.
