2011 NEC ROP CMP 5
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Transcript of 2011 NEC ROP CMP 5
February 18, 2009 12011 NEC ROP - CMP 5 Report to
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2011 NEC ROP CMP 5
Elliot RappaportDaleep Mohla
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Total Proposals Number of Proposals 324 Number of Panel Proposals 18 TIA 01 Accept 56 Accept in Part 06 Accept in Pr in Part 04 Accept in Principle 69
Reject 205
Redirected to other panels 02
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EEI Light and Power Task Force Proposals
16 proposals by EEI to redefine Service cable and Service Conductors to Service Entrance Cable and Service Entrance Conductors , definition of Ground Fault etc
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Definitions Proposal 5-10
Ground fault definition relocated to Article 100 Proposal 5-13
CMP 5 deleted the definition of Grounding conductor in place of correct term of Grounding Electrode Conductor.
Recommended formation of a TG of multiple panels to evaluate the impact of this change to other articles
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Color Coding of wires 200.6 (A) & (B) Rejected Proposal 5-36 to change color
coding from #6 AWG to # 10 AWG
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High Voltage CMP 503 Proposal 5- 51 a Changed “ high voltage” used in Article
250 to “Over 1 kV” to remove inconsistency with other articles where over 600 Volts is used as high voltage
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Ground Detection Systems Proposal 5-86 Panel rejected the proposal for equipment
for annunciation of ground detector system at a readily accessible location
Negative vote : The proposal should have been accepted in principle to ensure that a ground alarm is conveyed to an attended location for detection and mitigation purposes
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Ungrounded Systems Marking
CP 502 Proposal 5-86 a Ungrounded systems to be marked at the
source or at the first disconnecting means
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SSBJ 5-102 Introduces a new term Supply Side
Bonding Jumper and acronym (SSBJ) in 250.30.
This is called Equipment Bonding Jumper in 2008 NEC
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Metal Underground water pipe 5- 146 250.52(A)(1). Last paragraph ( 5 feet rule) and Industrial
exception have been relocated to new 250.68(C) because it pertains to usage of electrode.
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Industrial Exception 5-148 250.52 (A)(1) Exception
Panel rejected the proposal to remove industrial exception
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Concrete Encased ElectrodesSCC 18:Do we need to
comment? 5-150 250.52 (A)(2) Metal Frame of the Building or Structure. The metal
frame of the building or structure that is connected to the earth by any of the following methods:
(At least one structural metal member that is in direct contact with the earth for 3.0m ( 10 ft) or more, with or without encasement
(2) The hold- down bolts securing the structural member are connected to a concrete encased electrode that complies with 250.52(A)(3)…………..
Other methods( using other electrodes, other approved methods have been deleted)
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Ground Rod SizeVote negative?
5-168 250.52 (A)(5)(b) Panel rejected the deletion of underlined
text proposed by NEMA Grounding electrodes of stainless steel
and copper or zinc coated steel shall be at least 15.87 mm ( in.) in diameter, unless listed and not less than 12.70 mm (½ in.) in diameter.
Should NEC be establishing listing requirements?
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Supplemental Electrode Required
5-169b 250.53(A) A supplemental electrode is required where
rod, pipe, or plate electrode is used Exception: If a single rod, pipe , or plate
electrode has a resistance of 25 ohms or less, the supplemental electrode shall not be required.
FYI : Proposal 5-176a deleted 250.60 which had reverse requirement (second electrode is required if one is above 25 ohms)
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Air Terminal changed to Strike Termination Device
5-169b 250.53 (B); 5-179 250.60; 5-258 250.106 Changed Air Terminal to Strike Termination
Device to be consistent with NFPA 780
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Bonding JumpersNegative Vote or Affirmative
comment? 5-240 250.102 5-240 was Accepted in Principle by the
panel and title of 250.102 (C) was changed to
“SSBJ on Supply Side of an Overcurrent Device”
See next slide for statement
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Bonding JumpersNegative Vote or Affirmative comment
Title reads “SSBJ on Supply Side of an Overcurrent Device”. If the acronym of SSBJ in 250.30(A)(2) is used, it will read “ Supply Side Bonding Jumper on the Supply side of Overcurrent Protection device. Can SSBJ term be used accurately if the bonding jumper is on the load side of the overcurrent protective device?
The title should read “Bonding Jumper on Supply side of Overcurrent device”
Section 250.102(C) uses the acronym “SSBJ” which is defined only once in 250.30(A)(2). 250.102(C) Use of the acronym will reduce usability until the acronym is in general use by the industry. This may take several Code cycles. Until then, the acronym as well as the full name should be used
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250.104 (B) 2008 NEC B) Other Metal Piping. Where installed in or attached to
a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible
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CSST 5-251 250.104 (B) TIA 941 Panel rejected the proposal to require a split (B)
into two parts for metal piping other than CSST and CSST and require minimum # 6AWG Copper for bonding of Corrugated Stainless Steel Tubing (CSST) and follow table 250.66 to prevent damage to CSST due to direct and indirect lightning strikes.
Proposal alos mentioned that this is required by all CSST manufacturers
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CSST
Panel statement mentioned that : Not convinced that this will solve the problem as
no test data or substantiation has been provide to support the claim.
Panel was made awate that at least one other manufacturer does not require larger than as required by current 250.104
This is a product safety issue. Not currently prohibited by National Electrical
Code
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CSST TIA 941 IEEE plans to vote negative on TIA 941
in support of the panel
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Luminaire GroundingDiscussion
5-264 250.112 (J) Rejected by the panel 12-4 Submitter require all luminaires be provided with an equipment grounding conductor even for GFCI protected replavement luminaires exempted at present under 410.42 .
Submitter’s concern that a ground fault will energize the frame of the luminaire supplied by GFCI without an EGC and ground path will be provided by the person touching it.
Should we trust GFCI without EGC?
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EMT as an EGC?Negative vote by IEEE
5-272 250.118 (4) Panel rejected the proposal to delete EMT
as an equipment grounding conductor and require a separate EGC within EMT.
Concern is the ground path depends on connector ( not threaded) and couplings
IEEE plans to vote against the panel action with the statement on the next slide
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EMT as an EGC?Negative vote by IEEE
It is regrettable that, after many years of proposals indicating that there is a real problem on roof tops, Code Panel 5 continues to use the same answer of “no technical substantiation”. There probably is none but there is evidence of real world issues of fittings coming apart and leaving equipment ungrounded. EMT can be installed easily without adequate tightening of fittings or fittings get loose . As a result, the raceway is adequate for installing conductors but inadequate as an equipment grounding conductor. This issue will not go away as evidenced by the proposal at every Code cycle.
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Table 250. 122 5-281 Panel rejected proposal to replace table 250.122
based on overcurrent devices with a new table based on ungrounded conductor sizes as certain sizes of cables were not included
Concern cited is inability to parallel muticonductor UL listed cables that has a fixed size EGC since EGC has to be based on OCPD because following 250. 122 each cable requires a EGC based on the table
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EGC sizing in parallel cablepossible negative vote? Panel vote
10-6 5-287 250. 122 (A) Panel rejected the proposal to add
“including in parallel circuits” to 250.122(A) that does not require EGC to be larger than ungrounded conductor.
Concern cited by the submitter was a case where multiple 500 kcmil supplied by a 5000 A OCPD which requires 700 kcmil EGC ( larger than ungrounded conductors)
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Multigrounded system Don Zipse proposals 5- 311 and 5- 312 on
250.184 (A)(1) and 250.184 C respectively were rejected by the panel.
Don proposed 250. 184 C be deleted. This allows systems to be multi grounded
Panel statement indicated no adequate substantiation has been provided to delete this “safe option”
IEEE plans to vote negative on 5-312
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5-313 250. 184 CNegative vote by IEEE
The Panel Statement is not correct. This proposal has been presented many times in the past for each Code cycle. Each time the Proposer presents additional substantiation of the hazards of the multigrounded system without repeating the previous substantiation. New Panel members are remiss if they do not seek out the previous substantiation which is pertinent to deciding how to address this issue. The Panel Statement is not correct in stating that the multigrounded neutral system is safe. This section was added in a previous Code cycle without substantiation except to state that it was permitted in the National Electric Safety Code used by the Utilities. Use by the Utilities is for the purpose of protecting the linemen and does not address the issue of ground currents that are hazardous to the public.
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Shielded Cable 5-313 250.190 Panel accepted in principle this proposal Prohibits use of copper screen and ribbon
shield to be used as EGC in solidly grounded systems.
Panel action has been sent to CMP 6 and 10 for comments
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Shielded Cable 250.190 C (2) Shielded Cables If the cable assembly is suitably rated for
the ground fault current and is of the concentric neutral type, the shield conductor shall be permitted as the equipment grounding conductor. For solidly grounded systems, the cable copper screen or ribbon shield or combination of both shall not be used as equipment grounding conductor.
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Surge Arresters 280.5 Proposals 5-315 to 5- 319 Listing requirement of Surge Arresters has
been removed as no listed surge arresters are available
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Surge Protection Devices (SPD)
5- 323 Panel rejected a proposal to require a
status indication to indicate device is energized and some indication that it is no longer effective or usable.
Panel Statement : It is a product safety issue>
Is it or shall we require?
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SPD Type 3 5- 324 285.25 Type 3 SPDs
Panel accepted ( 11-5) a proposal to add tagquirement for Type 3 SPD’s
Type 3 SPD connection shall be a minimum of 10 m (30 feet) of conductor distance from the service or separately derived system disconnect if the Type 3 SPD includes cautionary marking, tag, or instructions statement pertaining to 10 m( 30 ft) distance