ARC FLASH HAZARD OVERVIEW. Presented August 13, 2015 WWOA Lake Michigan District by Mead & Hunt, Inc.

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1 ARC FLASH HAZARD OVERVIEW Presented August 13, 2015 WWOA Lake Michigan District by Mead & Hunt, Inc.

2 ARC FLASH EXPERIENCE Christopher J. DeWaal, MS, MEM, PE, LEED AP, HACCP How did I get involved? A client had an electrical incident that resulted in injury in 1998 and I was asked to help make their work environment safer. Engineers Thought Process: Will it work? Can we afford it? Safety...? This is the law! Wisconsin Administrative Code Chapter A-E 8.

3 COST OF UNSAFE SYSTEM Liability Costs 1999 Case Study by EPRI for CapSchell put the cost per incident (death) at $15.75 million 1998 National Electrical Contractors Association study put the cost per incident (injury) at $6 million Lost time, medical bills, lawyer s fees

4 SO WHAT? How common are electrical accidents? According to : NFPA 70E-2004, of the 350 Deaths in 2003 because of electricity, 50% were by arc flash CapSchell, there are 5-10 arc flash events every day in the US, resulting in 1-2 deaths per day NFPA 70E-2012, more than 2000 people are admitted to burn centers per year because of arc flash

5 WORKPLACE FATALITY STATISTICS

6 ELECTRICAL CURRENT EFFECTS ON THE BODY Estimated Effects of 60 Hz AC Currents Shock

7 WHAT IS ARC FLASH? It is not electrocution or shock. Arc Flash is the energy produced in an electrical circuit or electrical piece of equipment when an arc is produced.

8 WHAT CAUSES ARC FLASH? Worker s tools in contact with live parts Squirrel between transformer bushings Other conductive material in area

9 ARC FLASH EFFECTS According to Bussmann research, a fault producing 41 MVA will result in a temperature of 35,000 degrees F and up to 2,000 lbs./sq.ft. of pressure Surface of the Sun: 5k 9k degrees F 3rd Degree Burn: degrees F for 1 second Eardrum Rupture: 720 lbs./sq.ft.

10 ELECTRICAL SAFETY RULES NFPA 70E Standard for Electrical Safety Requirements for Employee Workplaces Installation Methods Safe Usage of Electrical Equipment Lock-Out, Tag-Out Arc Flash Limits of Approach

11 WORKER SAFETY RESPONSIBILITY NFPA 70E RESPONSIBILITY The employer shall provide the safety-related work practices and shall train the employee, who shall then implement them. Your safety is your responsibility!

12 ELECTRICAL SAFETY PROGRAM NFPA 70E ELECTRICAL SAFETY PROGRAM Created and maintained by the employer Must consider condition of maintenance of electrical equipment and systems 110.1(B) Must provide an awareness of the potential electrical hazards 110.1(C) Annex E gives examples

13 ELECTRICAL SAFETY PROGRAM NFPA 70E 110.1(G) RISK ASSESSMENT PROCEDURE 1. Identify hazards 2. Assess risks 3. Implement risk control according to hierarchy of safety controls: 1) Elimination 2) Substitution 3) Engineering Controls 4) Awareness 5) Administrative Controls 6) PPE

14 ELECTRICAL SAFETY PROGRAM NFPA 70E 110.1(H) JOB BRIEFING Before starting each job, the employee in charge shall conduct a job briefing with the employees involved. NFPA 70E 110.1(I) ELECTRICAL SAFETY AUDITING Program audited every 3 years Field work (LOTO, Arc Flash) audited every year Audits shall be documented

15 TRAINING REQUIREMENTS NFPA 70E 110.2(A) & (B) The training requirements contained in this section shall apply to employees exposed to an electrical hazard when the risk associated with that hazard is not reduced to a safe level by the applicable electrical installation requirements. Training can be classroom, on-the-job or a combination. NFPA 70E 110.2(C) EMERGENCY RESPONSE TRAINING Employees responsible for responding shall be trained in CPR, AED and first aid. Training shall be verified annually and documented

16 QUALIFIED & OUTSIDE PERSONNEL Qualified Person (NFPA 70E, 110.2(D)(1)) NFPA 70E 110.3(A), (B) & (C) Host Employer: Must inform contract employers of known hazards covered by NFPA 70E, give information about the installation that the contractor needs to made the assessments covered by NFPA 70E and report observed violations of this standard by contract employees to the contract employer Contract Employer: Must inform contract employees of known hazards covered by NFPA 70E as directed by host, insure that contract employees follow the work practices required by NFPA 70E and the host employer, and report unique hazards or hazards not mentioned by the host employer to the host employer. All meetings must be documented.

17 NFPA 70E ARTICLE 120 Verification of an Electrically Safe Work Condition Determine all possible sources of electrical supply, check applicable, up-to-date drawings 2. Open the disconnecting device(s) 3. Visually verify operation of disconnecting device(s) 4. Apply lockout/tagout devices (LOTO: pages) 5. Test each phase conductor or circuit part phase-to-phase and phase-to-ground 6. Ground phase conductors if induced or backfed electrical energy could exist (120.3)

18 NFPA 70E ARTICLE 130 Work Involving Electrical Hazards 130.2: Energized electrical conductors and circuit parts shall be put into an electrically safe work condition unless: 1. De-energizing introduces additional hazards or increased risk (life support systems, emergency alarm systems, hazardous location ventilation), or 2. Is infeasible in a de-energized state due to equipment design or operational limitations (diagnostics, testing, start-up, troubleshooting and work on circuits that form part of a continuous process).

19 NORMAL OPERATION (A)(4): Normal operation of electric equipment shall be permitted where all of the following conditions are satisfied: 1. The equipment is properly installed. 2. The equipment is properly maintained. 3. The equipment doors are closed and secured. 4. All equipment covers are in place and secured. 5. There is no evidence of impending failure.

20 NFPA 70E ARTICLE (B): Energized Electrical Work Permits are required when working within restricted approach boundary of exposed live parts that are not put into an electrically safe work condition or when the employee interacts with the equipment when it is not exposed, but a increased likelihood of injury from exposure to arc flash exists (B)(3): Exception for testing, troubleshooting, voltage measuring, thermography, visual inspection, access to or egress from the area or general housekeeping by QUALIFIED PERSONS

21 NFPA 70E ARTICLE : Approach Boundaries to Live Parts for Shock Protection Shock Protection Boundaries Limited and Restricted Approach Boundaries Limited Boundary - The closest an unqualified person can get to an exposed, energized circuit Restricted Boundary - Only qualified persons are allowed inside this boundary with proper PPE

22 APPROACH BOUNDARIES AC SYSTEMS

23 ARC FLASH RISK ASSESSMENT ARC FLASH RISK ASSESSMENT Shall be performed and shall: 1. Determine if an arc flash hazard exists. If one does, the assessment shall determine appropriate safety-related work practices, arc flash boundary and appropriate PPE. (Table 130.7(C)(15)(A)(a)) 2. Be updated when a major modification or renovation takes place. It shall be reviewed at least every 5 years. 3. Take into consideration the design of the OCPD, OCPD opening time and the condition of maintenance. The results of the assessment shall be documented.

24 ARC FLASH RISK ASSESSMENT 130.5(B) - ARC FLASH BOUNDARY Distance from energized circuit where a worker could receive an incurable burn (1.2 cal/sq. cm.) 130.5(C) ARC FLASH PPE One of the following methods (but not both) shall be used for the selection of PPE: 1. Incident Energy Analysis Method (Arc Flash Study) 2. Arc Flash PPE Categories Method (NFPA 70E Tables)

25 INCIDENT ENERGY ANALYSIS METHOD 1. Determine Energy Levels Short Circuit (SC) Study Power Protective Device Coordination (PDC) Study Time Arc Flash Hazard Analysis Power X Time = Energy 2. Recommendations Made to Reduce Energy Levels 3. Determine Appropriate Protective Equipment 4. Other Benefits: One-lines, system health assessment, etc.

26 ARC FLASH PPE CATEGORIES METHOD Table 130.7(C)(15)(A)(b) for AC systems Gives PPE categories for different equipment pieces Need to know available short circuit current, device clearing times and working distances (How do you do this?) Table 130.7(C)(15)(B) for DC systems similar to AC systems Table 130.7(C)(16) for PPE Categories

27 ARC FLASH LABELS Equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures and motor control centers shall be labeled with the following: 1. Nominal system voltage 2. Arc flash boundary 3. At least one of the following: a. Available incident energy / working distance or PPE category from NFPA 70E tables, but not both b. Minimum arc rating of clothing c. Site-specific level of PPE

28 ARC FLASH LABELS - EXISTING

29 PPE HARDHAT & FACESHIELD Hardhats w/ faceshield 8-12 Cal/cm2 Ultraviolet (UV) Infrared (IR) PROTECTION

30 ARC RATED CLOTHING Coveralls (shown) Hooded Parkas Bib Overalls Lab Coats

31 ARC FLASH CLOTHING

32 INSULATED HAND TOOL REQUIREMENTS All tools must be marked with the international safety symbol for 1000 Volts All tools must state the rating of 1000V All tools must have the name of manufacturer All tool must have the year of manufacture All tools must have the part number or code number All of this information must be marked on every tool These must be used inside the limited approach boundary

33 GLOVES FOR ELECTRICAL WORK

34 FACE SHIELD, ARC SUIT, COOLING VEST

35 ARC FLASH ENERGY MITIGATION Evaluate requirements Review circuit breaker settings to reduce incident energy Review fuse size and type to reduce incident energy Look at adding protective devices where necessary to reduce incident energy

36 ARC FLASH ENERGY MITIGATION Power Electronics VFD s do not allow current to flow back into fault, thus reducing energy in arc flash Cost savings in reduced energy and increased control Add impedance: Add or change transformers Dual Purpose: harmonics mitigation Dual Purpose: changing downstream load voltage Cost-effective during design and in retrofit Size cables closer to load Often oversized for future loads Dual Purpose: smaller wire = less cost Only cost-effective during design