DuPont Arc Guide An Integrated Methodology to Mitigating Electric Arc Hazards
Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 2
DuPont Safety Culture History Safety has become part of our DNA Powder mill operation began in 1802. Safety statistics began in 1912. Off-the-job safety program began in the 1950s. 1800 1850 1900 1950 2000 Belief that all injuries are preventable developed in the 1940s. First safety rules established in 1811. 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
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
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
Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 6
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 2 1.2 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 1584-2002 IEEE Guide for Performing Arc Flash Hazard Calculations- 7
What affects Arc Energy Level? Utility or HV Supply 11kV 400V Transformer AMOUNT OF CURRENT DURATION OF CURRENT 1 2 3 4 Protective device type or characteristic? Panel to be worked upon Fault Level in ka? 8
Incident Energy Exposure Level Based on: Equipment type Working Distance Working distance 9
Flash Protection Boundary Flash Protection Boundary The boundary within which a person could receive a second degree burn from an arc flash incident. Definition IEEE1584 10
Effect of distance on Incident Energy 11
Online DuPont Arc-Guide 12
Sample Calculation Typical European Medium-sized manufacturing company 13
Full calculation Projection 14
Full calculation Projection 15
Full calculation 16
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
Full Calculation Projection 18
Full calculation Progose Projection 19
Full calculation Projection 20
Calculation Projection 21
Calculation Projection 22
Full calculation Prevention 23
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 duty holder/champion Processes Written procedures Based upon risk assessment Clearly defined, written instructions Clear responsibilities Contractor competence Prevent 25
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
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
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
Publishing of results Risk Assessment Report Forms Training Labelling of switchgear and Control Panels Publish Results & Training 29
Publishing of results 30
Agenda 1. Introduction 2. Arc Hazard Risk Methodology - Predict - Prevent - Protect - Publish Predict Publish Prevent Protect 3. Wrap-up and closure 31
For Additional Info: www.arcguide.dupont.com Public website Full application & services Risk Assessment: Predict Prevent Protect Publish Access to experts