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Implementing NFPA 70E Electrical Safety Standards

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Presentation on theme: "Implementing NFPA 70E Electrical Safety Standards"— Presentation transcript:

1 Implementing NFPA 70E Electrical Safety Standards
St Louis, MO May 26, 2010

2 Topics Electrical hazards/injuries OSHA 1910 Subpart S
NFPA 70E requirements “Qualified” Worker”? Electrical Safe Work Practices Understanding arc flash hazard categories & PPE Understanding approach boundaries Implementing 70E and qualifying employees

3 Why it’s important…… 1,213 electrical related workplace fatalities from 2003 to 2007* 13,150 severe injuries* *Electrical Safety Foundation International 2008 Survey

4 Injuries from Electric Shock
Electrical Injuries Electrocution Electrical burns Nerve, muscle, tissue damage Internal bleeding Secondary injuries Falls Secondary injuries Burns Thermal burns Muscle, nerve, and tissue destruction Cardiac arrest and respiratory failure © Business & Legal Reports, Inc. 0912

Received when current passes through the body Severity of the shock depends on: Path of current through the body Amount of current flowing through the body Length of time the body is in the circuit LOW VOLTAGE DOES NOT MEAN LOW HAZARD Ground Exit

6 Electrical Safety Standards

7 OSHA Standards 29 CFR 1910

8 OSHA Standards 1910 Subpart S – Electrical
– .308 = Safe installation – .330 = Reserved – .335 = Work practices – .398 = Reserved – Definitions Appendix A – Reference Documents

9 Scope Applies to qualifed and unqualified employees performing work on: Premises wiring Connecting to supply Other wiring Optical fiber cable Does NOT apply to generation, distribution, or communication (specific standards for these) Refers to for definition of qualified persons.

10 “Qualified Person” – OSHA 1910.399
One who has received training in and has demonstrated skills and knowledge in the construction and operation of electrical equipment and installation and the hazards involved.

11 Training Employees who face a risk of electric shock that is not reduced to a safe level installation requirements must be trained. Occupations in Table S-4 must be trained. Other employees if they face a risk of shock.

12 Table S-4 Blue collar supervisors Electrical and electronic engineers
Electrical and electronic equipment assemblers Electrical and electronic technicians Electricians Industrial machine operators Material handling equipment operators Mechanics and repairers Painters Riggers and roustabouts Stationary engineers Welders Footnote(1) Workers in these groups do not need to be trained if their work or the work of those they supervise does not bring them or the employees they supervise close enough to exposed parts of electric circuits operating at 50 volts or more to ground for a hazard to exist.

13 1910.332 Training Training focused on: Recognizing live parts
Determining voltage of live parts Clearance distances specified in

14 1910.333 Selection and Use of Work Practices
Focused on work near exposed energized or potentially energized parts. Locking and tagging Deenergization Verifying deenergized condition Reenergizing Overhead power lines (clearance distances) Illumination Several other tasks

15 1910.333 Selection and Use of Work Practices
"Deenergized parts." Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations. Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs.

16 1910.334 Use of Equipment Covers things like: Portable equipment
Plugs and cords Reclosing circuits Inspection of equipment

17 1910.335 Safeguard for Personnel Protection
Personal Protective Equipment Must use when exposed Maintenance Inspection Insulated hand tools Guarding of exposed parts during work

18 NFPA 70E

19 Electrical Hazards NFPA 70E – A dangerous condition such that contact or equipment failure can result in: Electric Shock Arc flash burn Thermal burn Arc blast

20 Arc Flash & Arc Blast Arc Flash – electrical short circuit that occurs when air flashes from an exposed live conductor, to either another conductor or to ground. Arc Blast – pressure wave caused by the arc flash.

21 Arc Flash/Blast Concentrated energy explodes outward
High intensity flash Temperatures can reach 35,000 Pressure wave can reach 200lbs/sq. inch Vaporize conductors and copper and explode particles like buckshot.

22 Arc Flash Effects Severe burns Broken bones Vision damage Hearing loss
Brain/internal injuries Punctures and lacerations Death

23 Causes of Arc Flash Improper training Improper work procedures
Dropped tools Accidental contact with electrical systems Installation failure Inadequate SCCR Voltage testing with inappropriate equipment

24 Causes of Arc Flash (cont.)
Buildup of dust, corrosion on insulating surfaces Improper maintenance Sparks produced during racking of breakers, replacement of fuses and closing into faulty lines. Inattentiveness/Overconfidence

25 We’re in Missouri, so show me!
Racking a Breaker Breaker Box Demonstration

26 “Qualified Person” – NFPA 70
One who has the skill and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved. May be considered qualified with respect to certain equipment & method but still unqualified for others.

27 Qualified Persons Training Requirements
Understand specific electrical hazards Knowledgeable of the construction and operation of the equipment Identify & understand the relationship between electrical hazards and possibly injury Distinguish exposed live parts Able to determine voltage of live parts Understands and complies with arc flash and shock hazard boundaries.

28 Qualified Persons Training (cont.)
Proper use of precautionary techniques PPE, including arc-flash & shock protection Insulated tools Demonstrate how to select and use a voltage meter Decision-making process used to determine the degree and extent of the hazard

29 Justification for Work NFPA 70E 130.1
Energized electrical conductors and circuit parts to which an employee might be exposed shall be put into an electrically safe work condition before an employee works within the Limited Approach Boundary of those conductors or parts. Unless – the employer can demonstrate that de-energizing introduces additional hazards or is infeasible. Interruption of life support systems Deactivation of emergency alarm systems Shutdown of hazardous location ventilation systems Circuits and conductors that operate at less than 50 volts

30 Justification for Work NFPA 70E 130.1 (cont.)
Other work that may be performed within the limited approach boundary of exposed energized electrical conductors or circuits: Testing Troubleshooting Voltage measuring

31 Safe Work Practices De-energize-Lockout Policy
Don’t wear conductive apparel Work area must be illuminated Never reach into blind spots Don’t allow conductive liquids near electrical work or equipment Buddy system (over 1,000 volts, work in pairs) Do not defeat electrical interlocks Use nonconductive ladders

32 Steps to NFPA 70E Compliance
Have an arc hazard survey completed. Implement any recommendations to reduce the hazards. Develop and implement a labeling system. Determine what tasks will be performed and at what hazard category. Train (qualify) employees and provide PPE.

33 Arc Hazard Survey Conducted by an engineering firm Survey includes:
Single line diagram of electrical system Incident energy levels Current limiting device coordination Calculates a hazard risk category and approach boundaries Develops recommendations to reduce high hazard risk categories

34 Reduce the hazards! Some examples: Change fuses
Develop a maintenance program Adjust circuit breakers Install additional disconnects

35 Arc Flash Label

36 Arc Flash Label

37 Arc Ratings Hazard/Risk Category Incident Energy (cal/cm2) 0 - 1.2 1
1 2 4 - 8 3 8 - 25 4 Dangerous Over 40 *NFPA 70E Table 130.7(C)(11)

38 NFPA 70E Approach Boundaries

39 NFPA 70E Approach Boundaries (cont.)
The qualified worker is responsible for ensuring physical barriers are in place and all approach boundaries are enforced during work. Warning label provides boundary information Flash Boundary – 4 ft. or calculated Limited Prohibited Restricted

40 Specific Tasks Troubleshooting only! NO “WORK!”
Checking / replacing fuses Checking motor starters Checking amp draw Checking relays

41 Train….Train….Train….Train
3-step process…. Controls 101 Arc Flash Hazard Training Equipment Specific Training Hands on!

42 Arc Flash Hazard Training
Labeling system Glove selection and testing Shock protection Arc flash rated clothing Arc flash protection

43 Glove Labeling Chart Choose the right glove by voltage rating

44 Voltage-rated Gloves Salisbury video First line of defense
Choose the right size Leather protectors must be worn over the rubber gloves Gloves must be tested Before first issue and every 6 months If tested, but not issued for service, glove may not be put into service unless tested within previous 12 months. Checked before use Roll-up test Inflator test Salisbury video

45 Arc-Rated FR Clothing & PPE
Layering Outer layers must be flame resistant Under layers must be non-melting Fit – Clothing shall fit properly (loose), w/ least interference Coverage – Clothing must cover potentially exposed areas (wrist, neck) Care & Maintenance Inspect before use Launder according to mfg’s instructions *Photo courtesy of Salisbury

46 PPE - Hazard Risk Category 0 0-1.2 cal/cm2
100% cotton long sleeve shirt Long pants Safety glasses Hearing protection Leather and insulated gloves (as required) Leather work boots

47 PPE - Hazard Risk Category 1 1.2 - 4 cal/cm2
4+ cal long sleeve shirt & long pants (or) coveralls Hardhat Safety glasses Arc rated faceshield Hearing protection (inserts) VR gloves Leather gloves Leather work boots

48 PPE - Hazard Risk Category 2 4 - 8 cal/cm2
8+ cal long sleeve shirt & long pants (or) coveralls Hardhat Safety glasses Arc rated faceshield Hearing protection (inserts) VR gloves Leather gloves Leather work boots

49 PPE - Hazard Risk Category 3 8 - 25 cal/cm2
25+ flashsuit w/ hood over long sleeve shirt and long pants Safety glasses Arc rated faceshield Hearing protection (inserts) VR gloves Leather gloves Leather work boots

50 PPE - Hazard Risk Category 4 25 - 40 cal/cm2
40+ flashsuit w/ hood over FR long sleeve shirt and long pants Safety glasses Arc rated faceshield Hearing protection (inserts) VR gloves Leather gloves Leather work boots

51 Hands-On Training How to use a multi-meter Set up a safe scenario
Lockout upstream before class! Trainee performs Unacceptable performance = NOT qualified!

52 Qualification All steps completed Employees qualified Survey
Calculations PPE determination Training Employees qualified

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