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National Electrical Safety Code PowerPoint Presentation
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National Electrical Safety Code

National Electrical Safety Code

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National Electrical Safety Code

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    1. National Electrical Safety Code

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

    3. Basis For Computing Clearances

    4. Rule 230 - General No Significant Changes in 2002

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

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

    7. 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

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

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

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

    11. 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.

    12. 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.

    13. 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.

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

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

    16. 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.

    17. 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.

    18. 234C3d(1) - Attached to Buildings EXCEPTION 1: Where the voltage between conductors cable meets Rule 230C1 Revised Include voltages and cables over 750 volts.

    19. 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)

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

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

    22. 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.

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

    24. 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.

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

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

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

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

    29. 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.

    30. 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.