Tim Gangnon Assistant Manager of Loss Prevention Metropolitan Airports Commission Minneapolis St. Paul

Transcription

1 Electrical Safety Awareness 2014 ACI-NA Annual Risk Management Conference Tim Gangnon Assistant Manager of Loss Prevention Metropolitan Airports Commission Minneapolis St. Paul

2 Everything is fine, till it s not Great

3 This is a BAD day

4 Electrical Safety Awareness How does it effect your airport? What are the hazards? Electrical Shock ARC Blast Fire Protecting Your Airport Your Employees Contractors

5 Concerns at Your airport 1. Employee(s) or contractors being injured or killed due to an electrical incident. 2. Injuries to the traveling public 3. Damage to your assets and 4. Problems with your airlines. (How is your insurance program?) 5. Meeting Regulations OSHA, NFPA article 110 and 70E

6 So what s the problem?

7 What just happened? Injured employee and fatality (WC+) Damaged gear possible cascading affect. (Property) Powers is out what do I do?. Do you have backup? Can you get new equipment? How long? Business interruption

8 Electrical Harm Estimated Effects of AC Currents (U.S. Standard 60 Hz) 1 milliamp Barely perceptible (ma) 16 ma Maximum current an average man can grasp and let go ma Paralysis of respiratory muscles 100 ma Ventricular fibrillation threshold 2 Amps Cardiac standstill and internal organ damage 15/20/30 Amps Common U.S. household breakers PATH: Harm is related to the path by which current passes through the body. All Shock victims must be checked out medically

9 Fatal Shock Time Current Electrocution Path

10 However, If I move a leg no electrocution Time Current No Electrocution PATH

11 APU

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14 Burn Survival

15 What is Arc Flash? Arc flash results from an arcing fault, where the electric arcs and resulting radiation and shrapnel cause severe skin burns, hearing damage, and eye injuries.

16 Arc Flash An explosive release of energy caused by an electrical arc. An arc flash results from either a phase to ground or a phase to phase fault caused by such occurrences as accidental contact with electrical systems, build up of conductive dust, corrosion, dropped tools, and improper work procedures. During an arc flash, the temperature can reach 35,000 Every year, more than 2,000 people are admitted to burn centers with severe arc-flash burns.

17 Critical Facts Important Temperatures Skin temperature for curable burn Skin temperature causing cell death Ignition of clothing Burning clothing Metal droplets from arcing Surface of sun Arc terminals 176 F 205 F F 1472 F 1832 F 9000 F 35,000 F

18 Skin Damage Skin damage will occur based on the intensity of the heat generated by an electrical arc accident. The heat reaching the skin of the worker is dependant on the following three factors: Power of the arc at the arc location Distance of the worker to the arc Time duration of the arc exposure

19 Electrical Arc 35,000 F Molten Metal > 1800 F Pressure Waves > 2000 lb/psf Cu Sound Waves >140db Copper Vapor: Solid to Vapor Expands by 67,000 times Shrapnel > 740 mph Hot Air >500 F Intense Light

20 The Set up

21 The Explosion

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26 > Indicates Meter Pegged Results of this Test Sound ft. T2 >225 C / 437 F T3 P1 >2160 lbs/sq.ft T1 > 225 C / 437 F 50 C / 122 F

27 How Costly are these events?

28 Incident History This incident occurred at a meat company in Southern Wisconsin It resulted in one employee being in a coma in a burn unit for 3 months. Medical costs associated with this incident are in excess of one million dollars (closer to two million) OSHA Citations in excess of $145, Civil suits

29 Flash Protection Boundary and Limits of Approach Definitions of Boundaries and Spaces The closer you approach an exposed, energized conductor or circuit part, the greater the chance of an inadvertent contact and the greater the injury that an arc flash will cause. NFPA 70E-2004, Annex C defines approach boundaries and work spaces.

30 Flash Protection Boundary and Limits of Approach Flash Protection Boundary When an energized conductor is exposed, you may not approach closer than the flash boundary without wearing appropriate personal protective clothing and personal protective equipment.

31 Limited Approach Boundary Restricted Approach Prohibited Approach Boundary

32 Flash Protection Boundary and Limits of Approach NFPA 70E 2004, Table 130.2(C) NFPA Approach Boundaries to Live Parts for Shock Protection. (All dimensions are distance from live part to employee.) (1) (2) (3) (4) (5) Limited Approach Boundary 1 Nominal System Voltage Range, Phase to Phase Exposed Movable Conductor Exposed Fixed Circuit Part Restricted Approach Boundary 1 ; Includes Inadvertent Movement Adder Prohibited Approach Boundary 1 Less than 50 Not specified Not specified Not specified Not specified 50 to ft 0 in. 3 ft 6 in. Avoid contact Avoid contact 301 to ft 0 in. 3 ft 6 in. 1 ft 0 in. 0 ft 1 in. 751 to 15 kv 10 ft 0 in. 5 ft 0 in. 2 ft 2 in. 0 ft 7 in kv to 36 kv 10 ft 0 in. 6 ft 0 in. 2 ft 7 in. 0 ft 10 in kv to 46 kv 10 ft 0 in. 8 ft 0 in. 2 ft 9 in. 1 ft 5 in kv to 72.5 kv 10 ft 0 in. 8 ft 0 in. 3 ft 3 in. 2 ft 1 in.

33 In response to an inquiry on OSHA's stand on arc flash hazard, Richard S. Terrill, the Regional Administrator for Occupational Safety and Health, US Department of Labor for the Northwest Region at Seattle, concluded as follows: "Though OSHA does not, per se, enforce the NFPA standard, 2000 Edition, OSHA considers NFPA standard a recognized industry practice. The employer is required to conduct assessment in accordance with CFR (d)(1). If an arc flash hazard is present, or likely to be present, then the employer must select and require employees to use the protective apparel. Employers who conduct the hazard/risk assessment, and select and require their employees to use protective clothing and other PPE appropriate for the task, as stated in the NFPA 70E standard, 2000 Edition, are deemed in compliance with the Hazard Assessment and Equipment Selection OSHA standard."

34 What is a Hazard Risk Category (HRC)? HRC level is determined by the minimum amount of calories per square centimeter (ATPV or Cal/cm2). Any treated garment must pass through with a 50% probability of a 2nd or 3rd degree burn occurring, which is how the protective level of the treated clothing is determined. The higher the ATPV, the higher the HRC level attained, the greater the protection that is needed.

35 70E Tables Protective Clothing

36 Arc Flash Hazard Analysis (The One Line)

37 Arc Flash Hazard Analysis 1-Line

38 Labeling ( warning labels) When an arcing fault occurs, the result can be extremely high temperatures, a tremendous pressure blast and shrapnel (equipment parts) hurling at high velocity (in excess of 700 miles per hour).

39 ! WARNING Arc Flash and Shock Hazard Appropriate PPE Required Courtesy E.I. du Pont de Nemours & Co.

40 ! WARNING Arc Flash and Shock Hazard Appropriate PPE Required 24 inch Flash Hazard Boundary 3 cal/cm 2 Flash Hazard at 18 inches 1DF PPE Level, 1 Layer 6 oz Nomex, Leather Gloves Faceshield 480 VAC Shock Hazard when Cover is removed 36 inch Limited Approach 12 inch Restricted Approach V Class 00 Gloves 1 inch Prohibited Approach V Class 00 Gloves Equipment Name: Slurry Pump Starter Courtesy E.I. du Pont de Nemours & Co.

41 OSHA s Stand on Clothing: Apparel. (i) When work is performed within reaching distance of exposed energized parts of equipment, the employer shall ensure that each employee removes or renders nonconductive all exposed conductive articles... (ii) The employer shall train each employee who is exposed to the hazards of flames or electric arcs in the hazards involved. (iii) The employer shall ensure that each employee who is exposed to the hazards of flames or electric arcs does not wear clothing that, when exposed to flames or electric arcs, could increase the extent of injury that would be sustained by the employee. 08/19/1995 Standard Interpretation Guidelines for the Enforcement of the Apparel Standard

42 Employee Training 1. First Aid 2. Lockout/Tagout 3. Specialized equipment as specified by the manufacture. 4. What OSHA will be looking for.

43 Electrically Safe Work Conditions Lockout/Tagout A single qualified person de-energizing one set of conductors. An unqualified person may never perform a lockout/tagout, work on energized equipment, or enter high risk areas.

44 Electrically Safe Work Conditions The equipment is not and cannot be energized: To ensure an electrically safe work condition: Identify all power sources, Interrupt the load and disconnect power, Visually verify that a disconnect has opened the circuit, Locking out and tagging the circuit, Test for absence of voltage, and Ground all power conductors, if necessary.

45 NFPA 70E Boundaries and Spaces Good safety practices minimize risk: Switch remotely if possible. Standing aside and away as much as possible during switching. (LOL) Avoid leaning on or touching switchgear and metallic surfaces. Use proper tools and PPE.

46 OSHA Personal Protective Equipment Hazard Assessment PPE for Electrical Hazards Specific Work Practices NFPA 70E The General Duty Clause

47 NFPA 70E Requirements Arc flash boundaries must be known Safe approach distances established and maintained Marking equipment relative to hazards Electrically safe (voltage rated) tools PPE Training

48 Contractors

49 Host Employer Responsibilities 1. The host employer shall inform contract employers of the following: a. Known hazards that are covered by this standard, that are related to the contract employer s work, and that might not be recognized by the contract employer or its employees b. Information about the employer s installation that the contract employer needs to make assessments required. c. The host employer shall report observed contract employer-related violations of this standard to the contract employer.

50 Ground Fault Circuit Interrupters (GFCI) Monitors current flow between the hot and neutral wires Trip between 4-6 ma in 1/40th of a second

51 GFCI In construction all cords and equipment must be protected*. GFCI in line at the source not down stream. Cord inspection programs

52 Your Contractors- Locates

53 Energized Electrical Work Permit When live parts over 50 volts are not placed in an electrically safe work condition it is considered energized electrical work and must be done under a written permit. Permit gives conditions and work practices needed to protect employee from arc flash or contact with live parts.

54 Energized Electrical Work Permit An Energized Electrical Work Permit will include: Circuit, equipment and location Why working while energized. Shock and arc flash hazard analysis Safe work practices Approach boundaries Required PPE and tools Access control Proof of job briefing

55 Energized Electrical Work Permit

56 Arc Protection Clothing Requirements - OSHA 29 CFR (1)(6)(iii) Arc Protection Clothing Requirements - OSHA 29 CFR (1)(6)(iii) The employer shall ensure that each employee who is exposed to the hazards of flames or electric arcs does not wear clothing that, when exposed to flames or electric arcs, could increase the extent of injury that would be sustained by the employee. Clothing selected for a particular application shall have an arc thermal performance value of (EBT or ATPV) higher than the potential hazard to prevent the onset of 2nd degree burns.

57 ATPV or EBT What is ATPV? An acronym for Arc Thermal Performance Value, APTV is, in arc testing, the incident energy on a fabric or material that results in sufficient heat transfer through the fabric or material to cause the onset of a second degree burn based on the Stoll curve. What is EBT? An acronym for Energy Breakeven Threshold, EBT is the average of the five highest incident energy exposure values below the Stoll curve where specimens do not exhibit breakopen. Note: EBT is similar to ATPV, but is determined when breakopen occurs before the onset of a second degree burn.

58 ARC Rating Explained A value of the energy necessary to pass through any given fabric to cause with 50% probability a second or third degree burn. This value is measured in calories/cm². The necessary Arc Rating for an article of clothing is determined by a Hazard/Risk Assessment and the resulting HRC. Usually measured in terms of ATPV or EBT. Simple put the ARC rating determines the protective characteristics of the fabric. The higher the ARC rating value the greater the protection. When the product is sold to protect workers from arcing faults, clothing manufacturer are required in indicate the ARC rating.

59 Electrical Hazards

60 The Ground May Be Hot! Electricity dissipates with the resistance of the ground As potential drops, fields develop around the electrified machine If you step across a line of unequal potential, you could be electrocuted

61 A downed power line with current flowing will set up a step potential as indicated by the lines and arrows. Down Wire Step Potential

62 Other Issues

63 Self Audit

64 Preventive Maintenance

65 What you need Written Lockout/Tagout Policy PPE program for shock and arc flash Written Electrical Safe Work Practices Hazard assessment to determine shock and arc flash hazards Lockout/Tagout training Qualified electrical maintenance personnel with 70E training Lockout/Tagout equipment Appropriate voltmeters Insulated tools

66 Who can help?

67 For More Information: Check out: NFPA 70E (Current edition) National Electrical Code section 110 (Current edition)

68 Rubber Glove Training

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70 Questions?

71 Thank You Tim

72 ATPV An Arc Thermal Protective Value (ATPV) refers to the maximum incident energy (in calories per centimeter squared) that protective equipment can be exposed to and prevent to onset of a second-degree burn.

73 Maintain Safe Working Clearance All equipment ladders, scaffolds, cranes, trucks, forklifts, etc. MUST maintain a minimum 10 foot clearance from 50 kv or less Add.4 inches for every kv over 50 kv

74 Electrically Rated Tools

75 Labeling ( warning labels) An accidental slip of a tool or a loose part tumbling across live parts can initiate an arcing fault in the equipment. If a person is in the proximity of an arcing fault, the flash can cause serious injury or death. The point of the warning label is to remind qualified workers of the arc flash hazard when working on electrical equipment.

76 NFPA 70E PPE Tables Allows quick assessment of needs. Uses tables broken down by task to determine protective clothing. Based upon worse-case assumptions. Often over protective.

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