General Or Gc Electrical Safety

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General Or Gc Electrical Safety

  1. 1. Electrical Safety
  2. 2. AGENDA <ul><ul><li>Electricity's Beginning Onsite </li></ul></ul><ul><ul><li>Temporary Power/Lighting </li></ul></ul><ul><ul><li>GFCI vs. Circuit Breaker </li></ul></ul><ul><ul><li>Power Tools </li></ul></ul><ul><ul><li>Safe Guarding Permanent Power </li></ul></ul><ul><ul><li>Energized Work </li></ul></ul>
  3. 3. Electricity’s Beginning Onsite
  4. 4. Electricity's Beginning On Site <ul><li>The First Point of inspecting an electrical system is at it point of origin (1926.404(c)) </li></ul><ul><li>Ensure Overhead Lines (insulated) will be more than 8 feet away from future or existing buildings (NEC 225-19). </li></ul>
  5. 5. Electricity's Beginning On Site <ul><li>Ensure Service entrance lines have appropriate clearance distances from the ground (NEC 225-18) </li></ul><ul><ul><li>10’ sidewalks, accessible to pedestrians only, ect. </li></ul></ul><ul><ul><li>12’ over residential property and driveways no subject to truck traffic </li></ul></ul><ul><ul><li>15’ Same as 12’ but when voltage exceeds 300V </li></ul></ul><ul><ul><li>18’ Over public streets and areas subject to truck traffic </li></ul></ul>
  6. 6. Electricity's Beginning On Site <ul><li>Ensure the connection at the weatherhead is secure and seems capable of safely holding. </li></ul><ul><li>Ensure underground services are protected from damage (NEC 230-49 refers to table 300-5) </li></ul>
  7. 7. Temporary Power
  8. 8. Temporary Power <ul><li>After the Service entrance has been confirmed as safe the next step is to follow the conduits to the first Panel </li></ul>
  9. 9. Temporary Power <ul><li>Ensure Appropriate warnings and Labels are in place </li></ul><ul><ul><li>Flash Hazard (NEC 110.16) </li></ul></ul><ul><ul><li>Danger High Voltage (110.34 (c)) </li></ul></ul><ul><ul><li>For rooms and other guarded locations – Qualified Persons only (NEC 110.27(c)) </li></ul></ul><ul><ul><li>Reference Index of NEC: </li></ul></ul><ul><ul><ul><li>Labels Required and Warning Signs </li></ul></ul></ul>
  10. 10. Temporary Power <ul><li>Open the Panel and ensure: </li></ul><ul><ul><li>That no energized parts are accessible (1926.405(d)) </li></ul></ul><ul><ul><li>Circuits are identified for disconnecting purposes (1926.403(h)) </li></ul></ul>
  11. 11. <ul><li>Verify that all circuits are in the “on” position. </li></ul><ul><li>This is especially important in verifying that an effective lockout/tagout system is in place. </li></ul><ul><li>If a circuit is off, ask and verify why??? </li></ul>Temporary Power
  12. 12. Temporary Power <ul><li>Ensure that access to electrical rooms and panels are limited to qualified persons NEC 110-27 </li></ul>
  13. 13. Temporary Power <ul><li>Ensure Temporary Power (Plugs) are separate circuits from Temporary Lighting. (1926.405(a)(2)(ii)(c)) </li></ul>
  14. 14. Temporary Lights <ul><li>All bulb types must be protected from accidental contact or breakage at all times. (1926.405(a)(2)(ii)(E)) </li></ul><ul><li>Any empty light socket that does not contain a bulb exposes energized parts that can be a violation of 1926.416(a) or 1926.403(i)(2) exceptions listed A-D </li></ul>
  15. 15. Temporary Lights <ul><li>Temporary Lights are to be installed so as to protect the conductors from damage </li></ul><ul><ul><li>Hang fixtures as designed and not with conductive material. 1926.405(a)(2)(ii)(f) </li></ul></ul><ul><ul><li>Flexible cords are permissible if protected correctly. 1926.405(a)(2) – (ii)(I) and (ii)(J) </li></ul></ul>
  16. 16. GFCI vs. Circuit Breakers
  17. 17. GFCI vs. Circuit Breakers <ul><li>GFCI Specifications </li></ul><ul><ul><li>Will trip at 4-6mA </li></ul></ul>NOTE: A Ground Fault Circuit Interrupter (GFCI) limits the duration of an electrical shock to a period considered safe for healthy people. It does not prevent electric shock. This device does not protect against electric shock due to contact with both circuit conductors or a fault in any wiring supplying this device.
  18. 18. GFCI vs. Circuit Breakers <ul><li>Required to protect all Temporary Power circuits. </li></ul><ul><ul><li>Extension Cords become “temporary Power circuits” when plugged into permanent Receptacles. </li></ul></ul>
  19. 19. GFCI vs. Circuit Breakers <ul><li>Circuit breakers are Overcurrent protection devices which is one part of the overcurrent protection system. </li></ul><ul><li>Breaker/Fuse – Wire – Device </li></ul>
  20. 20. GFCI vs. Circuit Breakers <ul><li>GFCI for Portable Generators </li></ul><ul><ul><li>Required at 5KW (LOI 8/24/77) </li></ul></ul><ul><ul><li>Frame not required to be grounded NEC 250.34 and 1926.404(f)(3) </li></ul></ul><ul><li>GFCI Circuit Breakers </li></ul><ul><ul><li>For any Voltage </li></ul></ul>
  21. 21. Extension Cords
  22. 22. Extension Cords <ul><li>NEC References: </li></ul><ul><ul><li>240.5 Overcurrent Protection </li></ul></ul><ul><ul><li>Table 400.5(a) Flexible Cord allowable amps </li></ul></ul><ul><ul><li>Or 240.5(b)(3) extension cords considered protected when applied within the extension cord listing requirements </li></ul></ul>
  23. 23. Extension Cords <ul><li>guide for cords less than 50 ft. </li></ul><ul><li>#12 gauge - 1920 watts - 16 amps – large bench saws </li></ul><ul><li>#14 gauge - 1440 watts - 12 amps - portable power saws, routers </li></ul><ul><li>#16 gauge - 840 watts - 7 amps –Belt Sanders </li></ul><ul><li>, recip saws </li></ul><ul><li>#18 gauge - 600 watts - 5 amps - drills, small sanders </li></ul>
  24. 24. Extension Cords 25A 14A 9A 7A 10 17A 8.5A 5.7A 4.25A 12 11A 5.5A 3.7A 2.75A 14 50' 100' 150' 200' Cord Size Extension Cord Length Extension 120 V Extension Cord Maximum Ampacity
  25. 25. Extension Cords <ul><li>Prohibited Uses 1926.405(g)(1)(iii) </li></ul><ul><ul><li>as a substitute for the fixed wiring of a structure </li></ul></ul><ul><ul><li>Where run through holes in walls, ceilings, or floors. </li></ul></ul><ul><ul><li>Where run through doorways, windows, or similar openings not protected from pinch points. </li></ul></ul><ul><ul><li>Where attached to building surfaces or concealed behind walls, ceilings, or floors </li></ul></ul>
  26. 26. Extension Cords <ul><li>Shall be designed for hard or extra-hard usage. </li></ul><ul><ul><li>1926.405(a)(2)(ii)(J) </li></ul></ul><ul><ul><li>NEC Table 400.4 </li></ul></ul><ul><ul><li>Common Examples include – S, SO, SJ, SJT </li></ul></ul><ul><li>Shall be used only in continuous lengths without spice or tap. 1926.405(g)(2)(ii) </li></ul><ul><ul><li>#12 or larger may be repaired if spice retains insulation and usage characteristics </li></ul></ul>
  27. 27. Extension Cords <ul><li>NEC 400.21 Insulation shall not be less than specified </li></ul><ul><ul><li>If a visible amount of insulation has been removed it is in need removal or repair </li></ul></ul>
  28. 28. Power Tools
  29. 29. Power Tools From NFPA 70E 110.9(B)(1) <ul><li>Portable equipment must be handled in a manner which will not cause damage. Flexible electric cords connected to equipment may not be used for raising or lowering the equipment. </li></ul><ul><li>Flexible cords may not be fastened with staples or otherwise hung in such a fashion as could damage the outer jacket or insulation. </li></ul>
  30. 30. Power Tools From NFPA 70E 110.9(B)(3) <ul><li>Portable cord and plug connected equipment and flexible cord sets (extension cords) shall be visually inspected before use on any shift for external defects: </li></ul><ul><ul><li>Loose parts </li></ul></ul><ul><ul><li>Deformed or missing pins </li></ul></ul><ul><ul><li>Damage to outer jacket or insulation </li></ul></ul><ul><ul><li>Evidence of possible internal damage </li></ul></ul>
  31. 31. Power Tools <ul><li>If there is a defect or evidence of damage to any electrical tools or equipment… </li></ul><ul><li>Take it Out of Service </li></ul><ul><li>Imagine an employee dies while using the Power tool that you repaired. </li></ul><ul><li>Fatality at Trussville High </li></ul>
  32. 32. Ladders…. <ul><ul><li>Portable ladders must have non-conductive side rails if they are used where a workers or the ladder could contact exposed energized parts. </li></ul></ul><ul><ul><li>Keep all ladder parts at least 10 feet away from overhead power lines </li></ul></ul>
  33. 33. Controlling Permanent Power Through an effective Lock out / Tagout System
  34. 34. Controlling Permanent Power <ul><li>Prior to Energizing Permanent Power There are a few things to check </li></ul>
  35. 35. Controlling Permanent Power <ul><li>Check Main Switch Gear for Empty Conduits </li></ul><ul><ul><li>Why are they empty? </li></ul></ul><ul><ul><li>Are they capped? </li></ul></ul><ul><ul><li>Will Duct Tape work? </li></ul></ul>
  36. 36. Controlling Permanent Power <ul><li>Once the gear is energized there should be no reason to re-enter. </li></ul><ul><ul><li>Re-entering energized gear would require a scheduled “shut-down” with local utility company. </li></ul></ul><ul><ul><li>Or Gear must be designed to shut-down in sections. </li></ul></ul>
  37. 37. Controlling Permanent Power <ul><li>Check to Verify Lockout/Tagout Equipment is available. </li></ul><ul><li>Is there a LO/TO plan, who is the authorized person(s)? </li></ul><ul><li>Reference NFPA 70E 120 Establishing an Electrically Safe Work Condition </li></ul>
  38. 38. Controlling Permanent Power MSG EQ DP2 DP1 PP LP HVAC
  39. 39. Energized Work
  40. 40. Energized Work From NFPA 70E 130 <ul><li>Safety Requirements are the same wither the employee is working on or near energized parts </li></ul><ul><li>Voltage Testing, Trouble Shooting, working in a panel with the main in the off position but the lugs are energized. </li></ul>
  41. 41. Energized Work <ul><li>You must have justification to work on energized circuits or parts </li></ul><ul><ul><li>In short, if you are going to put other people’s lives in danger by turning off the power – you have justification. </li></ul></ul><ul><ul><li>A work permit and Job briefing/planning checklist must be completed before working energized </li></ul></ul>
  42. 42. Energized Work <ul><li>If there is any chance circuits or parts may be energized, they are to be treated as energized until verified as de-energized, meaning PPE required. </li></ul>
  43. 43. Energized Work <ul><li>Use barricades to prevent or limit access to work areas with un-insulated energized conductors or circuit parts </li></ul><ul><li>Or an attendant shall be stationed to warn and protect employees </li></ul>
  44. 44. Topics Discussed <ul><ul><li>Electricity's Beginning Onsite </li></ul></ul><ul><ul><li>Temporary Power/Lighting </li></ul></ul><ul><ul><li>GFCI vs. Circuit Breaker </li></ul></ul><ul><ul><li>Power Tools </li></ul></ul><ul><ul><li>Safe Guarding Permanent Power </li></ul></ul><ul><ul><li>Energized Work </li></ul></ul>
  45. 45. QUESTIONS?

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