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NESC Subcommittee 2

. . . Presentation Objectives: Working Group 2.1 Report- Section 2 Definitions. Definitions for different types of grounded or ungrounded electric supply systems. Subcommittee 2- Section 9, Grounding Methods for Electric Supply and Communications Facilities, 2002 NESC. NESC Grounding Methods. . .

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NESC Subcommittee 2

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    1. NESC Subcommittee 2

    3. NESC Working Group 2.1 Established 1996 -Provide definitions of methods to ground electric supply systems. Proposed Definitions appear in the 2002 NESC Pre-print. Comment period resulted in some revision.

    4. Grounding Definitions Section 2- New definitions related to system grounding. Multigrounded/multiple grounded system Neutral conductor Shield wire conductor Single grounded/unigrounded Ungrounded system

    5. NESC Subcommittee 2 Section 9 revisions Rule number system changed (Example- Rule 93. is now Rule 093.) Metallic (underline is an addition) Part (Strikethrough is a deletion)

    6. Section 9 Revisions Rule 093AMetallic electrical equipment cases or the structural metal frame of a building or structure may serve as part of a grounding conductor to an acceptable grounding electrode.

    7. Section 9 Revisions, Cont.. Rule 093C4. EXCEPTION: Arrester grounding conductors may be copper-clad or aluminum-clad steel wire having not less than 30% of the conductivity of solid copper or aluminum wire of the same diameter, respectively.

    8. Section 9 Revisions, Cont.. Rule 094B2b. Longer rods or multiple rods may be used to reduce the ground resistance. Spacing between multiple rods should be not less than 1.8 m (6 ft) EXCEPTION: Other dimensions or configurations may be used if their suitability is supported by a qualified engineering study

    9. Section 9 Revisions, Cont.. Rule 096C. Multi-grounded systems RECOMMENDATION: This Rule may be applied to shield wire(s) used as lightning protection conductor(s), which is grounded at the source and that meets the multigrounding requirements of this Rule

    10. Section 9 Revisions, Cont.. Rule 097A. (Note 3 has moved to note 4 and a new note 3 is added) 3. Shield wires of power circuits

    11. Section 9 Revisions, Cont.. 097B- The grounding conductors of either of the equipment classes detailed in Rules 97A1, and 97A2, and 97A3 may be interconnected utilizing a single grounding bonding conductor, provided: 2. The secondary neutral, or the grounded secondary phase conductor is common with or connected to primary neutral, or a shield wire...

    12. Section 9 Revisions, Cont.. Rule 097D. Ungrounded or Single-Grounded and Multi-Grounded Systems 1. Ungrounded or Single-Grounded Systems Where the secondary neutral is not interconnected with the primary surge-arrester grounding . The primary grounding conductor, or the secondary grounding conductor, shall be insulated for 600 V.

    13. Section 9 Revisions, Cont.. Rule 097G. Except where separation is required in Rule 97A, communication systems messengers are to be grounded on a joint use structure containing an electric supply grounding electrode conductor, the grounding system of the communication system should be bonded with the grounding electrode conductor of the electric supply system. Where the electric supply utility is maintaining isolation between primary and secondary neutrals, the communication system ground shall be connected to the primary ground conductor.

    14. Section 9 Revisions, Cont.. Rule 099C. Bonding of Electrodes A bond not smaller than AWG No. 6 copper or equivalent shall be placed between the communication grounding electrode and the supply system neutral grounding electrode where separate electrodes are used in or on the same building or on the same served structure.

    15. Section 9 Revisions, Cont.. A bond not smaller than AWG No. 6 copper or equivalent shall be..served structure. RECOMMENDATION : If water piping is used as a bonding means, care must be taken to assure that the metallic path is continuous between electrodes. Note: See NEC Article 800-40(d) for corresponding NEC requirements.

    16. ?? Questions ??

    17. Part 1. Electric Supply Stations

    18. Section 10. Purpose and Scope The purpose of Part 1 is to provide practical safeguarding of persons performing installation, operation, or maintenance duties in electric supply stations.

    19. Section 10. Purpose and Scope The scope covers the electric supply conductors, equipment and structural arrangements in electric supply stations, that are accessible only to qualified personnel including equipment employed primarily for the utilization of electric power used by the utility in the exercise of its function as a utility.

    21. A1. Types of Enclosures Metal fences, when used to enclose electric supply stations having energized electric conductors or equipment, shall have a height not less than 7 ft overall and shall be grounded in accordance with Section 9. 110. General Requirements

    22. A1. Types of Enclosures a. Fence Fabric, 7 ft or more in height b. A Combination of 6 ft or more or fence fabric and utilizing 3 or more strands of barbed wire to achieve an overall height of the fence of not less than 7ft. 110. General Requirements

    23. A2. Safety Clearance Zone Fences or walls, when installed as barriers for unauthorized personnel, shall be located such that exposed live parts are outside the safety clearance zone as illustrated in Figure 110-1 and shown in Table 110-1. 110. General Requirements

    25. B. Rooms and Spaces All rooms and spaces shall comply with the following requirements: 1. Construction They shall be as much as practical noncombustible. NOTE: This Rule is not intended to prevent wood poles from being used to support conductors or equipment in electric supply stations.

    26. B. Rooms and Spaces 2. Use They should be as much as practical free from combustible materials, dust, and fumes and shall not be used for manufacturing or for storage. EXCEPTION 1: Equipment or materials essential for maintenance of installed equipment may be stored if guarded from live parts as required by Rule 124

    27. B. Rooms and Spaces EXCEPTION 2: Materials related to station, transmission, or distribution construction and maintenance work may be stored in the station if located in an area separated from the station electric supply equipment by a fence meeting the requirements of Rule 110A.

    28. B. Rooms and Spaces EXCEPTION 3: Stored material related to station, transmission, and distribution construction and maintenance work in progress may be temporarily located in a storage space meeting all of the following requirements:

    29. B. Rooms and Spaces (1) Guarded or separated from live parts as required by Rule 124 (2) Station exits continue to meet the requirements of Rule 113 (3) Station working space continues to meet the requirements of Rule 125 (4) Access is limited to qualified personnel (5) The storage location and content is such that the risk of fire does not unreasonably jeopardize station operation.

    35. Section 15. Transformers and Regulators

    36. 150. Current-Transformer Secondary Circuits Protection When Exceeding 600 Volts (Old Rule) Secondary circuits, when in a primary voltage area exceed 600 V should, except for short lead lengths at the terminals of the transformer, have the secondary wiring adequately protected by means of grounded conduit or by a grounded metallic covering. Current transformers shall have provision for shorting the secondary wiring.

    37. 150. Current-Transformer Secondary Circuits Protection When Exceeding 600 Volts (New Rule) Secondary circuits, when in the vicinity of primary circuits exceeding 600 V should, except for short lead lengths at the terminals of the transformer, have the secondary wiring adequately protected by means of conduit covering or some other protection. Any metallic covering used shall be effectively grounded, giving appropriate consideration to circulating currents. Current transformers shall have provision for shorting the secondary winding.

    38. Section 17. Circuit Breakers, Reclosers, Switches, and Fuses

    40. National Electrical Safety Code

    41. Summary Introduce Each Rule Category in Section 23 Describe Any Significant 2002 Changes Brief Reason for Each Change

    42. Basis For Computing Clearances

    43. Rule 230 - General No Significant Changes in 2002

    44. Rule 231 - Structures and Other Objects Clearances of Supporting Structures From Other Objects

    45. Rule 231A - Fire Hydrants Not less than 1.2 m (4 ft) ... Revised Rule Clearance changed to recommendation Exception aligned with previous clearance

    46. Rule 231B1 - From Streets, Roads,... Where there are curbs: Revised Rule Included anchor guys Defined redirectional curbs Defined paved or swale-type curbs and placed facilities behind such curbs

    47. Rule 232 - Vertical Clearances Vertical Clearances of Wires, Conductors, Cables, and Equipment Above Ground, Roadway, Rail, or Water Surfaces

    48. Rule 232B3 - Equipment Cases Clearance to Support Arms and Equipment Cases Revised to include Support Arms

    49. Rule 232B4a - Street & Area Lighting a. The vertical clearance of street and area lighting Revised Include vertical clearances of street light luminaries above ground.

    50. Table 232-1, Footnote 13 Where this construction crosses over or runs along alleys, not subject to truck traffic Revised Clarify for use in areas not subject to truck traffic.

    51. Table 232-1, Footnote 26 When designing a line to accommodate oversized vehicles, clearance values shall be increased by the difference between the known height of the oversized vehicle and 4.3 m (14 ft). New Clarify treatment of large vehicles.

    52. Table 232-2 - Category 2a Add footnote 7; lessor clearances for grounded equipment cases to Category 2a; Roads, Streets, and alleys Revised Allow reduced clearances for equipment if it does not overhang roadway.

    53. Rule 233 - Different Structures Clearances Between Wires, Conductors, and Cables Carried on Different Supporting Structures

    54. Rule 234 - Other Installations Clearances of Wires, Conductors, Cables, and Equipment From Buildings, Bridges, Rail Cars, Swimming Pools, and Other Installations

    55. Rule 234C3a - Attached to Buildings Energized service drop conductors 1) For 0 to 750 V, Rules 230C or 230 D 2) For over 750V, Rule 230C1 Revised Include service voltages over 750 volts.

    56. Rule 234C3c - Attached to Buildings Wires or cables attached to and run along side the installation not less than 75 mm (3 in). Revised Calls out a specific value instead of referencing a table.

    57. 234C3d(1) - Attached to Buildings EXCEPTION 1: Where the voltage between conductors cable meets Rule 230C1 Revised Include voltages and cables over 750 volts.

    58. Rule 234F - Grain Bins All portions of grain bins In addition, the following clearances shall also apply a. A clearance not less than 5.5 m (18 ft) b. horizontal clearance not less than 4.6 m (15 ft)

    59. Rule 234F - Grain Bins (cont) Revised Clearances based on physical distances instead of voltage class.

    60. Rule 235 - Same Supporting Structure Clearance for Wires, Conductors, or Cables Carried on the Same Supporting Structure

    61. 235C2b(1) - Between Line Conductors c) For purposes of this determination Adds new rule c) which has summer loading (i), winter loading (ii), and an exception for a single utility with equal cables. Revised Re-organized the rule for clarity under various loading conditions. Excludes cables of same type and single ownership.

    62. Rule 235H - Communication Spacing Clearance and Spacing Between Communication Conductors, Cables, and Equipment New Adds guidance for placing communication equipment on structures.

    63. Rule 235I - Communication Antennas Clearances in Any Direction From Supply Line Conductors to Communication Antennas in the Supply Space Attached to the Same Supporting Structure New Handle communication antennas located in the supply space, which is becoming a common practice.

    64. Rule 236 - Climbing Space Climbing Space No Significant Changes in 2002

    65. Rule 237 - Working Space Working Space No Significant Changes in 2002

    66. Rule 238 - Communication & Supply Vertical Clearances Between Certain Communication and Supply Facilities Located on the Same Structure No Significant Changes in 2002

    67. Rule 239 - Other Facilities On Structure Clearances of Vertical and Lateral Facilities From Other Facilities and Surfaces on the Same Supporting Structure

    68. Rule 239A6 - Guards & Protection 6. Where guarding and protection are required by other Rules, New Clarifies such guards should completely enclose the cable to ensure their protection.

    69. Table 239-1 - Footnote 5 5These clearances may be reduced to not more than 25% New Footnote added to Row 2 of Table. Provide same reduced clearances as conductors from guy insulators.

    71. NESC 2002 Strength & Loading Review NESC 1997 NESC 2002 (Resolved/Final) Comparison

    72. NESC 1997 Winter Storm Combined Ice and Wind Loading (Rule 250B) Heavy (0.5-in. radial ice, 40 mph wind, 0F) Medium (0.25-in. radial ice, 40 mph wind, 15F) Light (0-in. radial ice, 60 mph wind, 30F)

    87. Status of Major Change Proposals Eliminate 60 ft. exemption for Extreme Wind (CP 2151) Rejected (WG 5.8 to study for 2007) Introduce New Combined Ice and Wind Map as alternative to present Storm Loading Map, Rule 250B (CP 2309) Rejected (map incomplete, premature, inaccurate?)

    88. Status of Major Change Proposals (Contd) New Materials: Fiber-Reinforced Composite Poles (CP 2219, ) Rejected (insufficient material data) Major Revision of Strength & Loading Sections 25 - 27 (CP 2372) Rejected (WG 5.2 to continue developing for 2007)

    89. Status of Major Change Proposals (Contd) Uniform Treatment of Wood, Metal, Concrete (Reinforced, Prestressed) Consistent Overload Factors (CP 2233) Accepted All structures without conductors subject to Extreme Wind (CP 2306) Accepted

    90. Consistent Overload Factors (Wood, Metal, Concrete)

    91. Status of Major Change Proposals (Contd) New Extreme Wind Map (CP 2363) Accepted + New Calculation Procedure

    92. New Extreme Wind Map & Calculation Procedure ASCE 7-98 Extreme Wind Map 50 year recurrence (0.02 annual probability) Gusts (3-second average) Open terrain 33 ft. elevation Includes Gust Response Factors Height Span length

    93. New Extreme Wind Map & Calculation Procedure Retains 60 ft. Exemption (Distribution)

    95. New (2002) Extreme Wind Map (3 Second Gusts)

    96. New Extreme Wind Map & Calculation Procedure NESC-1997 load (lbs) =0.00256 (Vmph)2 x shape factor x projected area (ft2) where Vmph = fastest-mile (Figure 250-2, 1997) NESC-2002 load (lbs) =0.00256 (Vmph)2 x shape factor x projected area (ft2) x kz x GRF x I where Vmph = 3-sec. gust (New Extreme Wind Map), kz = velocity pressure exposure coefficient, GRF = gust response factor, and I = importance factor (=1.0)

    97. Structure: kz =2.01 x (0.67h/900)(2/9.5), 60 ft ? h ? 900 ft where h = height structure (ft) Wire: kz =2.01 x (h/900)(2/9.5), 33 ft ? h ? 900 ft where h = height attachment point (ft) minimum kz =0.85 New Extreme Wind Map & Calculation Procedure (Contd)

    98. New Extreme Wind Map & Calculation Procedure (Contd) Structure: GRF =[1 +2.7Es(Bs)0.5]/kv2 Wire: GRF =[1 +2.7Ew(Bw)0.5]/kv2 where Es =0.346 x [33/(0.67h)]1/7 Ew =0.346 x [33/h]1/7 Bs =1/[1 +0.375h/220] Bw =1/[1 +0.8L/220] kv =1.43 L =Design Wind Span (ft)

    99. New Extreme Wind Map & Calculation Procedure (Contd)

    101. NESC 2002 vs. NESC 1997 Comparison Reduced Overload Factor for Metal, Prestressed-Concrete Rule 250B (Combined Ice + Wind) Transverse wind Grade C (not crossing) 1.75 vs. previous 2.20 Affects distribution and transmission Extreme Wind Loading (Rule 250C) 3-sec. gust map & calculation procedure Affects transmission design only (>60 ft.)

    102. NESC 2002 vs. NESC 1997 Comparison (Contd) Distribution Lines (Combined Ice-Wind) Wood, Reinforced-Concrete no change Metal, Prestressed-Concrete reduced design load (transverse, Grade C, )

    103. NESC 2002 vs. NESC 1997 Comparison (Contd) Transmission Lines Wood, Reinforced-Concrete no change in Combined Ice/Wind design loads new Extreme Wind design loads Metal, Prestressed-Concrete reduced Combined Ice/Wind design loads (transverse, Grade C, ) -- 0.80 factor new Extreme Wind design loads

    104. Transmission Lines Structures - Combined Ice & Wind

    105. Transmission Lines Structures - Extreme Wind

    106. Transmission Lines Structures - Extreme Wind

    107. Transmission Lines Conductors - Combined Ice & Wind

    108. Transmission Lines Conductors - Extreme Wind

    109. Examples (Transverse Wind Load)

    111. Heavy Storm District (Wood)

    112. Wood Transmission Heavy Storm Area, Grade B, 250 x 500

    113. Wood Transmission Heavy Storm Area, Grade B, 100 x 2000

    114. Wood Transmission Heavy Storm Area, Grade B, 50 x 2000

    115. Wood Transmission Heavy Storm Area, Grade C, 250 x 500

    116. Wood Transmission Heavy Storm Area, Grade C, 100 x 2000

    117. Wood Transmission Heavy Storm Area, Grade C, 50 x 2000

    118. Heavy Storm District (Steel)

    119. Steel Transmission Heavy Storm Area, Grade B, 250 x 500

    120. Steel Transmission Heavy Storm Area, Grade B, 100 x 2000

    121. Steel Transmission Heavy Storm Area, Grade B, 50 x 2000

    122. Steel Transmission Heavy Storm Area, Grade C, 250 x 500

    123. Steel Transmission Heavy Storm Area, Grade C, 100 x 2000

    124. Steel Transmission Heavy Storm Area, Grade C, 50 x 2000

    125. Medium Storm District (Wood)

    126. Wood Transmission Medium Storm Area, Grade B, 250 x 500

    127. Wood Transmission Medium Storm Area, Grade B, 100 x 2000

    128. Wood Transmission Medium Storm Area, Grade C, 250 x 500

    129. Wood Transmission Medium Storm Area, Grade C, 100x2000

    130. Medium Storm District (Steel)

    131. Steel Transmission Medium Storm Area, Grade B, 250 x 500

    132. Steel Transmission Medium Storm Area, Grade B, 100x2000

    133. Steel Transmission Medium Storm Area, Grade C, 250 x 500

    134. Steel Transmission Medium Storm Area, Grade C, 100x2000

    135. Light Storm District (Wood)

    136. Wood Transmission Light Storm Area, Grade B, 250 x 500

    137. Wood Transmission Light Storm Area, Grade B, 100 x 2000

    138. Wood Transmission Light Storm Area, Grade C, 250 x 500

    139. Wood Transmission Light Storm Area, Grade C, 100 x 2000

    140. Light Storm District (Steel)

    141. Steel Transmission Light Storm Area, Grade B, 250 x 500

    142. Steel Transmission Light Storm Area, Grade B, 100 x 2000

    143. Steel Transmission Light Storm Area, Grade C, 250 x 500

    144. Steel Transmission Light Storm Area, Grade C, 100 x 2000

    146. NESC 2002 vs. NESC 1997 Conclusions Distribution Design Loads Wood ? Same Reinforced-concrete ? Same Metal (Grade C) ? Reduced in Grade C Prestressed-concrete (Grade C) ?Reduced in Grade C

    147. NESC 2002 vs. NESC 1997 Conclusions Transmission design loads depend upon combination of parameters - geographic area - grade of construction - material - conductor diameter - attachment height - span length

    149. Integrated Re-Write of Strength & Loading Based upon CP 2372 (Rejected for NESC-2002) Sags and Clearances also impacted Modified version proposed for NESC-2007 Edition To be available on NESC website (when?) Response form provided for reporting results of application to actual cases!

    150. New Extreme Wind Map and wind pressure calculation procedure (Rule 250C, NESC-2002) Upgraded ASCE 7-98 Combined Ice and Wind Map Replaces Fig.250-1 Loading Districts Construction and Maintenance Loads Integrated Re-Write of Strength & Loading

    151. All loads apply to all structures independent of height, but ... Possible wind reduction if urban/suburban and ? 60 ft. (Ref: Working Group 5.8) Ice thickness reduction for Grade C Velocity pressure exposure coefficient kz and gust response factor GRF (functions of height and span length) applied to wind pressure for both storm loads Integrated Re-Write of Strength & Loading

    152. Consistent Overload and Strength Factors Alternative (Option) to Present (NESC-2002) Method ? Integrated Re-Write of Strength & Loading

    153. Results from actual applications (as reported on response forms) will be considered in developing final proposal for 2007 Edition Integrated Re-write of Strength & Loading (Contd)

    154. WHATS NEW IN 2002? NESC Significant Changes Underground Lines

    156. RANDOM SEPARATION

    157. RANDOM SEPARATION

    158. RARANDOM SEPARATION

    159. RANDOM SEPARATION

    160. IDENTIFICATION MARKING BURIED CABLE

    161. New NESC Rule 323C5 5. Any manhole greater than 1.25 m (4 ft) in depth shall be designed so it can be entered by means of a ladder or other suitable climbing device. Equipment, cables and hangers are not suitable climbing devices. Reason: This rule was added because it was not adequately covered in the code.

    162. New NESC Rule 350H H. The rules in this section also apply to direct buried supply and communications cables installed in duct that is not part of a conduit system. (the section referenced above is section 35, rules for direct buried cables) Also a NOTE will be added at the beginning of section 32 (Underground Conduit Systems) thusly:

    163. New NESC Rule 350H (cont.) For cables installed in a single duct not part of a conduit system, the rules in section 35 apply. Reason: This rule was added to clarify the intent of the code that the direct buried cable rules in Section 35 apply to direct buried cable in duct that is not part of conduit system.

    164. Revised NESC Rule 351A1 351A1 Cables should be located so as to be subject to the least disturbance practical. When cables are Cables to be installed parallel to other subsurface structures, but if this is not practical, the rules on separation in Rule 352 353 or 354 shall should be followed.

    166. Revised NESC Rule 352 and 354 Presently the separation rules require a 12 separation between supply cables and other underground structures, including gas and other fuel lines. If this is not practical, or conditions do not permit it, then a separation of less than 12 (random lay) is OK, provided all parties affected are in agreement and the random lay rules are followed.

    167. Revised NESC Rule 352 and 354 (cont.) The revised rules on separation will be two distinct rules: (1) Revised Rule 353 for deliberate separation (Equal to or Greater Than 12), And (2) Revised Rule 354 for random separation (Less Than 12).

    168. The most significant change is new NESC Rule 354A2 which states: 354A2. Radical separation of supply and communication cables or conductors from steam lines, gas and other fuel lines shall be not less than 12 inches and shall meet Rule 353. The present rules do not allow a supply cable and gas line to have a separation of less than 12 provided all the affected parties agree, but the new Rule 354A2, as stated above, will not allow a radical separation less than 12, even if the parties agree to it, or if they are owned by the same utility. The 2002 edition will have no exceptions.

    169. Reason: This rule was added because of the concerns between supply and communica- tion cables and gas lines as to adequate separation.

    170. Revised NESC Rule 353D1, Table 353-1, Exception Exception: Where conflicts with other underground facilities exist, street light cables operating at not more than 150 volts to ground may be buried at a depth not less than 450 mm (18 in). Reason: This rule was revised because the original intent was to allow a lessor depth only where other underground structures existed. The burial depth should correlate with voltage, not the type of system being installed.

    171. New NESC Rule 380D D. Padmounted equipment, pedestals and otherabove ground enclosures should be located not less than1.2 m (4 ft) from firehydrants. Exception:Where conditions do not permit a clearance of 1.2 m (4ft), a clearance of not less than 900 mm (3 ft) is allowed. Reason: This rule was added because padmounted equipment creates the same problems for firemen, as do overhead structures. It will also now be consistent with the overhead clearance section.

    172. Revised NESC Rule 381G1 381G1. Padmounted and other above ground equipment shall have an enclosure that is either locked or otherwise secured against unauthorized entry. Reason: This rule was revised so that non-padmounted equipment, such as secondary pedestals are included.

    173. NESC Subcommittee 8

    174. NESC Subcommittee 8 Work Rules PURPOSE IS TO PROVIDE PRACTICAL WORK RULES

    175. NESC Subcommittee 8 Work Rules HARMONIZED WITH OSHA FINAL RULES 1910.137 & 1910.269

    176. NESC Subcommittee 8 Work Rules RULE 410A2 - TRAINING DEMONSTRATED PROFICIENCY NESC AND OTHER RULES

    177. NESC Subcommittee 8 Work Rules RULE 411D SIGNS AND TAGS WARNING SIGNS ? EMPLOYEE SAFETY

    178. NESC Subcommittee 8 Work Rules RULE 423C4 AIR SPACE OR BARRIER WITH TORCH OR FLAME NEAR EXPOSED GAS OR FUEL LINE

    179. NESC Subcommittee 8 Work Rules RULE 423D5 SHORING PROVISIONS

    180. NESC Subcommittee 8 Work Rules RULES 431A1 & 431A2 JOINT USE COMMUNICATIONS & SUPPLY ENERGIZED UNTIL DE-ENERGIZED AND GROUNDED

    181. NESC Subcommittee 8 Work Rules RULE 431B ALTITUDE CORRECTION FACTORS MINIMUM APPROACH DISTANCES CORRECTED FOR COMMUNICATION WORKERS

    182. NESC Subcommittee 8 Work Rules TABLE 431 APPROACH DISTANCE ? DISTANCE TO EMPLOYER (MATCH 441 TABLES)

    183. NESC Subcommittee 8 Work Rules RULE 441A DEFINITION OF DE-ENERGIZED

    184. NESC Subcommittee 8 Work Rules RULE 441A TWO TERMS DE-ENERGIZED DE-ENERGIZED AND GROUNDED

    185. NESC Subcommittee 8 Work Rules RULE 441A3b & c AND TABLE 441-6 MAXIMUM USE VOLTAGE

    186. NESC Subcommittee 8 Work Rules RULE 441A4a TRANSIENT OVERVOLTAGE CONTROL VOLTAGES ABOVE 72.5kV

    187. NESC Subcommittee 8 Work Rules RULE 441A5a & b ALTITUDE CORRECTION CALCULATION CLARIFICATION ONLY

    188. NESC Subcommittee 8 Work Rules RULE 441B4a, b & c SPECIAL RULES FOR WORKING ON INSULATOR ASSEMBLIES OVER 72.5kV 3 INSULATORS SHORTED

    189. NESC Subcommittee 8 Work Rules NEW RULE 447 MOVED FROM RULE 276 MORE APPROPRIATE IN PART 4

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