2008 ROC- CMP 05 report to SCC 18
Summary
Requiring SCC 18 guidance
Comment# / ROP # / NEC reference / Brief Description / Panel Action at the meeting / Vote / IEEE vote recommendation5-80 / 5-146 / 250.52(A) (1) Exc / Add Institutional to Industrial & Commercial / Accept / 9-6 / Reject
5-134 / 5-239 / 250.104 (B) Exc / Add NFPA 780 reference / APr
add to 250.106 / 9-5 / Reject
5-161 / 5-318 / 250.154 (A)(1)Exc / Bare grounded conductors / Reject / 14-1 / ??
5-162 / 5-335 / Art 280 / Surge Arresters 1 kV and over / APr / 14-0 / Reject
Information of SCC 18 members where IEEE plans to vote Accepting Panel action
Comment / ROP / NEC Ref. / Brief Description / Panel Action / Vote / IEEE Vote recommendation5-85 / 5-145 / 250.52(A)(3) / Grounding of structural members (removed use of water pipe) / A / 14-0 / A
5-86 / 5-152 / 250.52(A)(3) / Concrete encased electrodes. Vertical rebars allowed / A / 14-0 / A
5-87 / 5-135 / 250.52(A)(3) / Require at least one CE electrode if concrete footing is used / R / 14-0 / A
5-90 / 5-155 / 250.52(A)(4) / Grounding lateral instead of grounding rings / R / 14-0 / A
5-92 / 5-155 / 250.52(A)(4) / Add reference to IEEE 80 for grounding rings / R / 14-0 / A
5-102 / 5-178 / 250.62 / Identify GE conductor with a green stripe / R / 14-0 / A
5-121 / 5-214 / 250.68(B) / Removed permanent from Effective Ground Fault path / APr / 14-0 / A
5-141 / 5-265 / 250.119 (1) / Green allowed as current carrying for Power limired Class2 or 3 circuits / APr / 14-0 / A
5-153 / 5-284 / 250.122 (D) / EGC for Motor circuits protected by IT CB or MSCP are now required to be sized based on max permitted dual element TD fuses / APr / 14-0 / A
2008 ROC Comment 5-80
Comment and Panel Action
5-80 Log #1115 NEC-P05 Final Action: Accept
(250.52(A)(1))
______
Submitter: Andre R. Cartal, Princeton Borough Building Dept.
Comment on Proposal No: 5-146
Recommendation: Please accept the proposal to add the word "institutional."
Substantiation: The panel comment "CONCLUDES" that institutional buildings are INCLUDED, but the Panel's comment doesn't count as they REJECTED the proposal.
Panel Meeting Action: Accept
______
Recommendation: IEEE Vote against the panel action to accept Vote 9-6
This requires adding word “institutional” to 250.52 (A)(1) Exception in addition to Industrial and Commercial Installations. I am opposed to adding Institutional simply because it is not defined and will open the window larger. Many challenges have been made to remove industrial and commercial exceptions in the last two Code cycles. Adding “institutional” to this category may result in additional challenges and loss of this tool to the Industrials also
Proposal
5-146 Log #2293 NEC-P05
(250.52(A)(1 ))
Final Action:
Submitter: Andre R. Cartal, Princeton Borough Building Dept.
Recommendation: Revise text to read as follows:
Add "institutional" to the building/structures that are permitted.
Substantiation: There is no reason to exclude institutions. For example, Princeton University employs an electrical
maintenance team of licensed and trained electricians that easily meet the requirements.
Panel Action on Proposal
5-146 Log #2293 NEC-P05 Action: Reject
(250.52(A)(1) Exception)
______
Submitter: Andre R. Cartal, Princeton Borough Building Dept.
Panel Meeting Action: Reject
Panel Statement: The panel concludes that the qualification for commercial buildings includes institutional facilities where conditions of maintenance and supervision ensure that only qualified persons will service the work.
______
Comment 5- 134
5-134 Log #2223 NEC-P05 Final Action: Accept in Principle
(250.104(B))
______
Submitter: Technical Committee on Lightning Protection
Comment on Proposal No: 5-239
Recommendation: Revise the existing Fine Print Note in 250.104(B) as follows:
FPN: Bonding all piping and metal air ducts within the premises will provide additional safety. For structures with a lightning protection system, NFPA 780 requires that all grounding media on a structure be interconnected to provide a common ground potential. This interconnection includes lightning protection, electric service, telephone, and communication system grounds, as well as underground metallic piping systems. For further information see NFPA 780-2004, Standard for the Installation of Lightning Protection Systems.
Substantiation: This submission corrects the procedural error incorporated in the original proposal correctly indicated in the panel's rejection of the original submission.
Panel Meeting Action: Accept in Principle
Retain existing Fine Print Note following 250.104(B). Move the remaining text to a new FPN No. 3 following Section 250.106 to read as follows:
FPN No. 3: For structures with a lightning protection system, NFPA 780 requires that all grounding media on a structure be interconnected to provide a common ground potential. This interconnection includes lightning protection, electric service, telephone, and communication system grounds, as well as underground metallic piping systems. For further information see NFPA 780-2004, Standard for the Installation of Lightning Protection Systems.
Panel Statement: The panel moved the FPN to Section 250.106 to consolidate all lightning protection explanatory information.
______
Recommendation: IEEE vote against the panel action Vote 9-5 (chair abstained)
This expanded the FPN under 250.104 (B) to specifically reference NFPA 780 for bonding pf metal pipes . Panel also located this to 250.106 FPN series
Vote was 9- 5 IEEE was one of the 5
Concerns are that 1) NFPA 780 is already referenced in FPN1 and do we need to reference it more? Second is a concern that will electoral people doing power work be expected to comply with NFPA 780 if it is referenced so prominently for bonding of pipes. Lightning protection is a special field and inclusion of spotty requirements may be misleading
5-162 Log #975 NEC-P05 Final Action: Accept in Principle
(280)
______
Submitter: Mark C. Ode, Underwriters Laboratories Inc.
Comment on Proposal No: 5-335
Panel Meeting Action: Accept in Principle
Revise 2008 NEC ROP Draft of Article 280 to read as follows:
Recommendation : IEEE Vote negative to highlight:
¨ To remove listing requirements for surge arresters 1 kV and over
¨ To remove reference to obsolete technology of Silicone Carbide arresters by informing that IEEE Standards referenced in FPN for this technology have been withdrawn since 2000. NEC only mentions Si- Ca by name and may cause confusion that this is the only technology endorsed by the Code ( it does not mention MOV technology used by all manufacturers for 1 kV and over surge arresters)
¨ Surge arresters, most commonly, are supplied installed with transformers and switchgear .
¨ Large transformers are not required to be listed due to lack of any UL listing category a
¨ Listed Surge arresters are not available in the current UL listing book and as checked with major suppliers such as Siemens, Eaton, GE etc all ( see unofficial email response from Mark Ode below
From: [mailto:
Sent: Friday, December 22, 2006 10:51 AM
To:
Subject: Re: Surge arresters >1 KV
Daleep: I just looked for listings in the over 600 volt surge arresters and there are none at this time
¨ Silicone Carbide technology is obsolete and is no longer used by any Surge arrester manufacturer. MOV technology is currently only one available
¨ C62.1-1989 (R1994) 'IEEE Standard for Gapped Silicon-Carbide Surge Arresters for AC Power Circuits' was withdrawn in March 2000.
¨ C62.2-1989 (R1994) 'IEEE Guide for the Application of Gapped Silicon-Carbide Surge Arresters for Alternating Current Systems' was withdrawn in March 2000
(See email from Dave Ringle below)
From: [mailto:
Sent: Wednesday, December 06, 2006 6:09 PM
To:
Subject: RE: C62 standards
Daleep,
According to our database:
C62.1-1989 (R1994) 'IEEE Standard for Gapped Silicon-Carbide Surge Arresters for AC Power Circuits' was withdrawn in March 2000.
C62.2-1989 (R1994) 'IEEE Guide for the Application of Gapped Silicon-Carbide Surge Arresters for Alternating Current Systems' was withdrawn in March 2000.
Panel Meeting Action: Accept in Principle
Revise 2008 NEC ROP Draft of Article 280 to read as follows:
Article 280
Surge Arresters, Over 1kV
I. General
280.1 Scope. This article covers general requirements, installation requirements, and connection requirements for surge
arresters installed on premises wiring systems over 1 kV.
280.2 Uses Not Permitted. A surge arrester shall not be installed where the rating of the surge arrester is less than the maximum continuous phase-to-ground power frequency voltage available at the point of application.
280.3 Number Required. Where used at a point on a circuit, a surge arrester shall be connected to each ungrounded conductor. A single installation of such surge arresters shall be permitted to protect a number of interconnected circuits, provided that no circuit is exposed to surges while disconnected
from the surge arresters.
280.4 Surge Arrester Selection. The surge arresters shall comply with 280.4(A) and (B).
(A) Rating. The rating of a surge arrester shall be equal to or greater than the maximum continuous phase-to-ground operating voltage available at the point of application.
(1) Solidly grounded systems. The maximum continuous operating voltage shall be the phase-to-ground voltage of the system.
(2) Impedance- or ungrounded system. The maximum continuous operating voltage shall be the phase-to-phase voltage of the system.
(B) Silicon Carbide Types. The rating of a silicon carbide-type surge arrester shall not be less than 125 percent of the rating specified in 280.4(A).of the maximum continuous phase-to-ground voltage available at the point of application.
FPN No. 1: For further information on surge arresters, see
ANSI/IEEE C62.1-1989, Standard for Gapped Silicon-Carbide Surge Arresters for AC Power Circuits;
ANSI/IEEE C62.2-1987, Guide for the Application of Gapped Silicon-Carbide Surge Arresters for Alternating-Current Systems;
ANSI/IEEE C62.11-1999, Standard for Metal-Oxide Surge Arresters for Alternating-Current Power Circuits (>1 kV); and
ANSI/IEEE C62.22-1997, Guide for the Application of Metal-Oxide Surge Arresters for Alternating-Current Systems.
FPN No. 2: The selection of a properly rated metal oxide arrester is based on considerations of maximum continuous operating voltage and the magnitude and duration of overvoltages at the arrester location as affected by phase-to ground faults, system grounding techniques, switching surges, and other causes. See the manufacturer’s application rules for selection of the specific arrester to be used at a particular location.
280.5 Listing. A surge arrester shall be a listed device.
II. Installation
280.11 Location. Surge arresters shall be permitted to be located indoors or outdoors. Surge arresters shall be made
inaccessible to unqualified persons, unless listed for installation in accessible locations.
280.12 Routing of Surge Arrester Grounding Conductors.
The conductor used to connect the surge arrester to line, bus, or equipment and to a grounding conductor connection
point as provided in 280.21 shall not be any longer than necessary and shall avoid unnecessary bends.
III. Connecting Surge Arresters
280.21 Connection. The arrester grounding conductor shall be connected to one of the following:
(1) Grounded service conductor
(2) Grounding electrode conductor
(3) Grounding electrode for the service
(4) Equipment grounding terminal in the service equipment
280.23 Surge-Arrester Conductors. The conductor between the surge arrester and the line and the surge arrester and
the grounding connection shall not be smaller than 6 AWG copper or aluminum.
280.24 Interconnections. The grounding conductor of a surge arrester protecting a transformer that supplies a
secondary distribution system shall be interconnected as specified in 280.24(A), (B), or (C).
(A) Metallic Interconnections. A metallic interconnection shall be made to the secondary grounded circuit conductor or
the secondary circuit grounding conductor provided that, in addition to the direct grounding connection at the surge
arrester, the following occurs:
(1) Grounded Conductor Connection to Grounding Additional Grounding Connection. The grounded conductor of
the secondary has elsewhere a grounding connection to a continuous metal underground water piping system.
However, In urban water-pipe areas where there are at least four water pipe connections on the neutral conductor and
not fewer than four such connections in each mile of neutral conductor, the metallic interconnection shall be permitted to
be made to the secondary neutral conductor with omission of the direct grounding connection at the surge arrester.
(2) Grounded Conductor Part of Multi-Grounded Neutral Multi-Grounded Neutral System Connection. The
grounded conductor of the secondary system is a part of a multi-grounded neutral system or static wire of which the
primary neutral conductor or static wire has at least four grounding connections in each mile of line in addition to a
grounding connection at each service.
(B) Through Spark Gap or Device. Where the surge arrester grounding conductor is not connected as in 280.24(A) or
where the secondary is not grounded as in 280.24(A) but is otherwise grounded as in 250.52, an interconnection shall
be made through a spark gap or listed device as follows:
(1) Ungrounded or Uni-Grounded Primary System. For ungrounded or uni-grounded primary systems, the spark gap
or listed device shall have a 60-Hz breakdown voltage of at least twice the primary circuit voltage but not necessarily
more than 10 kV, and there shall be at least one other ground on the grounded conductor of the secondary that is not
less than 6.0 m (20 ft) distant from the surge arrester grounding electrode.
(2) Multi-Grounded Neutral Primary System. For multi-grounded neutral primary systems, the spark gap or listed
device shall have a 60-Hz breakdown of not more than 3 kV, and there shall be at least one other ground on the
grounded conductor of the secondary that is not less than 6.0 m (20 ft) distant from the surge arrester grounding
electrode.
(C) By Special Permission. An interconnection of the surge arrester ground and the secondary neutral conductor,
other than as provided in 280.24(A) or (B), shall be permitted to be made only by special permission.
280.25 Grounding Conductor Connections and Enclosures.
Except as indicated in this article, surge arrester grounding conductor connections shall be made as specified in Article
250, Parts III and X. Grounding conductors installed in metal enclosures shall comply with 250.64(E).
Panel Statement: Revised the proposed titles to clarify the contents of the section. Revised the text in 280.24(A)(2)
for clarity on the types of connections. This comment also incorporates the changes from Comment 5-163 and added
the word "operating" to be technically correct.
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