DuPont Arc Guide An Integrated Methodology to Mitigating Electric Arc Hazards

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1 DuPont Arc Guide An Integrated Methodology to Mitigating Electric Arc Hazards

2 Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 2

3 DuPont Safety Culture History Safety has become part of our DNA Powder mill operation began in Safety statistics began in Off-the-job safety program began in the 1950s Belief that all injuries are preventable developed in the 1940s. First safety rules established in Safety is a line management responsibility. No employee may enter a new or rebuilt mill until a member of top management has personally operated it. E. I. du Pont Goal is Zero established in 1990s. 3

4 DuPont Aims to Help Safety Managers with the Challenges Faced by Electric Arc INDUSTRY CHALLENGES... Assess Hazard severity Comply with EU Directives Implementation of risk reduction & protection measures Selection of Appropriate PPE for residual risks DuPont Engineering Research & Technology DuPont Protection Technologies- Makers of Nomex Expert External Consultants 4

5 Our Methodology for Approaching Arc Risk Hazards Re-evaluate YES Predict Severity Results Can we apply further prevention techniques? START Calculate Validate Predict Prevent Risk Reduction Hierarchy of risk controls NO Publish Results & Training Information Training Labelling Publish Protect Apply Protection Measures Residual risk Optimum solutions Residual Risk 5

6 Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 6

7 Arc Flash Hazard Assessment How do we measure the extent of the hazard? Calculate the Incident Energy, which defines the severity of the arc flash at a certain distance Measured in kj/m 2, J/cm 2, or cal/cm cal/cm 2 applied to skin for 1 second: the threshold for the onset of second degree burns Governs the arc flash boundary -Based on IEEE Guide for Performing Arc Flash Hazard Calculations- 7

8 What affects Arc Energy Level? Utility or HV Supply 11kV 400V Transformer AMOUNT OF CURRENT DURATION OF CURRENT Protective device type or characteristic? Panel to be worked upon Fault Level in ka? 8

9 Incident Energy Exposure Level Based on: Equipment type Working Distance Working distance 9

10 Flash Protection Boundary Flash Protection Boundary The boundary within which a person could receive a second degree burn from an arc flash incident. Definition IEEE

11 Effect of distance on Incident Energy 11

12 Online DuPont Arc-Guide 12

13 Sample Calculation Typical European Medium-sized manufacturing company 13

14 Full calculation Projection 14

15 Full calculation Projection 15

16 Full calculation 16

17 Full calculation Select the number of wires in the cable. Choose between copper and aluminum cables Choose the cross-section of the cable Select the number of parallel cables. Enter the cable length. 17

18 Full Calculation Projection 18

19 Full calculation Progose Projection 19

20 Full calculation Projection 20

21 Calculation Projection 21

22 Calculation Projection 22

23 Full calculation Prevention 23

24 First Calculation: Second Calculation: Replacement of NH fuse by ultra-rapid fuse Prevention 24

Prevent: Risk Elimination Safe Systems of work Human Factors The importance of Human Factors Awareness of the hazard Training and competence assessment Electrical

25 Prevent: Risk Elimination Safe Systems of work Human Factors The importance of Human Factors Awareness of the hazard Training and competence assessment Electrical duty holder/champion Processes Written procedures Based upon risk assessment Clearly defined, written instructions Clear responsibilities Contractor competence Prevent 25

26 Protecting against residual risk Residual risk after all mitigation measures in place Personal protective equipment The European legislative framework Body protection Layering Everyday workwear Additional protection Hand face and eye 26

27 Ensuring Fit-for Purpose Garments for Your Situation Arc Rating Body Protection ATPV > 4 cal/cm2 Box Test Class 1 ATPV > 8 cal/cm2 Box Test Class 1 Long Sleeved Business Shirt Long Sleeved Polo Shirt Jacket Trousers Coverall Coat ATPV > 12 cal/cm2 Box Test Class 1 ATPV > 25 cal/cm2 Box Test Class 2 ATPV > 40 cal/cm2 Box Test Class 2 Weather Jacket & Trouser 27

28 Layering with solutions made from NOMEX fabrics Lightweight comfortable layering offering relevant level of protection Ensure worker is not restricted from cumbersome clothing Possible Nomex multi-layer systems include Underwear Shirts/jackets/trousers/coveralls Polo Shirts Sweatshirts Multi-layer jackets and trousers High Visibility Foul weather gear Multi- layer systems for short duration wear for high level incident energy risks Hand Protection Eye/Face/Head Protection Source: Centurion Source: J & K Ross Source:J + K Ross Source: Dehn

29 Publishing of results Risk Assessment Report Forms Training Labelling of switchgear and Control Panels Publish Results & Training 29

30 Publishing of results 30

31 Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 31

32 For Additional Info: Public website Full application & services Risk Assessment: Predict Prevent Protect Publish Access to experts

Appendix A: Energized Work Permit

Appendix A: Energized Work Permit Part I: To be completed by the Supervisor Description of Circuit & Equipment: Job Location: Description of Work to Be Done: Justification of why the circuit cannot be