ELECTRICAL SAFETY TASK GROUP Task Group 5 Risk

ELECTRICAL SAFETY TASK GROUP Task Group 5 Risk Assessment and Arc Flash Controls for Normal Operations Greg Christensen, INL Gregory. christensen@inl. gov July 18, 2016

PARTICIPANTS • • • Earl Myott Russ Moder Mike Minard Glen Mirocha Frank Perrotta Glenn Anderson Greg Christensen Robert Fry Ray Joggerst Rick Ramirez Dan Evans Omar Al Atassi • • Scot Winningham Jennifer Martin Jerald Kinz Todd Kujawa Craig Shaw Kevin Gurbisz Tommy Martinez Jaqueline Mirabal. Martinez • Matthew Giardina • Jackie Mc. Alhaney

BACKGROUND NFPA 70 E 2015 Employers are responsible for assessing the risk from the arc hazard for employees that interact with electric equipment

BACKGROUND NFPA 70 E recognizes arc flash hazards may exist even when equipment is in an enclosed condition. This includes operators whose only interaction is with the equipment in an enclosed condition. There are situations where opening or closing a switch or breaker has been a contributing factor to an arc flash event.

GOAL Develop a best practice for: • Risk Assessment and recommendations for verifying proper installation, minimum maintenance requirements and no evidence of impending failure for assigning arc flash controls

BEST PRACTICE Elements of Best Practice • Risk Assessment – Verifying Proper Installation – Minimum inspection, testing and maintenance requirements for overcurrent protection devices (OCPDs) – Verifying no evidence of Impending failure – Additional considerations i. e. engineering controls, configuration, environment, venting, egress, documentation, etc.

ASSESSING RISK – Installed properly – Maintained properly – Doors closed and secured – Covers in place and secured – No evidence of impending failure Documentation required!

THRESHOLDS FOR ARC FLASH ≤ 125 KVA at < 240 V and < 1. 2 cal/cm 2 @480 Volts is exempted (assumes calculated in accordance with approved method in accordance with NFPA 70 E or IEEE 1584)

VERIFY INSTALLATION Electrical Inspection Program – Task Based Risk Assessment 1) Permit - Obtain an Electrical Work Authorization Document or Electrical Installation Permit 2) Engineered - Engineering Design Document that has taken into consideration the environment and application of the equipment to be installed. 3) Inspection or Examination – Inspection performed by a qualified NEC inspector or an AHJ delegated to perform such inspections. 4) Approved or Accepted– The inspection is approved and documented by NEC Inspector or AHJ, & work authorization document or permit is closed. 5) Required Labeling – Visual indication that the installation was performed in accordance with the required by applicable standards. i. e. Stickered

VERIFY INSTALLATION Electrical Inspection Program – Task Based Risk Assessment Qualified Person’s Initial Observation of Equipment Installation – Real Time Risk Assessment 1) Covers in place (screws, fasteners are engaged) 2) All penetrations are closed or sealed (is venting in the front? ) 3) Conduits, Fittings are secured and complete 4) Handle or Switching mechanism is intact (appears functional) 5) Equipment meets field labeling requirements (reviewed in last 5 yrs) 6) No Suspect/Counterfeit/Recalls 7) Field Modifications have been evaluated

VERIFY INSTALLATION Resources: NFPA 70 Definitions: Approved, Qualified Person, Authority Having Jurisdiction NFPA 70 Article 90. 7 & 110. 3 Examination, Identification, Installation and Use of Equipment NFPA 70 Article 110. 2 Approval of Conductors and Equipment NFPA 70 Article 110. 16 Arc Flash Hazard Warning Labels NFPA 70 Article 110. 24 (A) Maximum Available Fault Current Labeling & (B) Modifications NFPA 70 E 2015 Article 130. 5 (D) Arc Flash Risk Assessment Equipment Labeling

OVERCURRENT PROTECTION Need to Maintain overcurrent protection

Power Breakers • • • 3 – 5 year Cycle Cleaning and inspection Lubrication Thermal imaging Torqueing connections Mechanical exercise

Power Breakers Performance Testing Needed • Secondary or primary current injection • Instantaneous test to validate trip mechanism and arc flash calculation • Ground fault, short term and long term delay to validate equipment protection

Molded Case Circuit Breakers • 3 – 5 Year Cycle • Cleaning and inspection, torque connections, • Thermal Imaging - Energized, with loading greater than 40% of rating with covers removed • Torque connections to ensure no hot spots • Mechanical exercise

Molded Case Circuit Breakers Performance tests should be performed: • Instantaneous testing performed to validate trip time of breaker and arc analysis results. • Short Term and Long Term Delay should be performed to validate equipment protection

Fuses • 3 - 5 Year Cycle • Cleaning and inspection • Check fuse clips for tightness

Tools • Torqueing • calibrated tools • Document and record values • Torque per manufacturer’s requirements • Remote racking equipment

Resources and references NFPA 70 E Standard for Electrical Safety in the Workplace 2015 Chapter 2 NFPA 70 B Recommended Practice for Electrical Equipment Maintenance IEEE Recommended Practice for the Selection, Field Testing and Life Expectancy of Molded Case Circuit Breakers for Industrial Applications NEMA AB 4 Guidelines for Inspection and Preventative Maintenance of Molded Case Circuit Breakers Used in Commercial and Industrial Applications

IMPENDING FAILURE

PRACTICAL CONCERNS 25 cal/cm 2 Incident Energy • • Properly installed Properly maintained Cover on and secure no evidence of impending failure Risk = high consequence/low probability Consensus of the group some level of PPE is still recommended for this risk.

RISK Low Probability High Consequence Severity Low Probability Low Consequence High Probability High Consequence High Probability Low Consequence Frequency

PPE for OPERATIONS If bounding conditions are NOT met then arc rated clothing and PPE must meet the available incident energy level • >40 cal/cm 2 remote racking or other engineered control to remove the employee from the hazard zone should be employed • Consider Hierarchy of Controls

PPE for OPERATIONS If risk assessment indicates the conditions for proper installation, maintenance and no evidence of impending failure are met: • Underlayer must be non-melting • Minimum for outer layer is non melting • Arc rated clothing recommended > 1. 2 cal/cm 2

CONCLUSION • Risk assessment to evaluate bounding conditions for proper installation, maintenance and no evidence of impending failure must consider many discreet factors to be effective and provide a high level of safety for breaker operations. See also EFCOG Best Practice #192 “Guide to Incorporating Risk Assessment into ISM for Electrical Safety”

POSSIBLE FUTURE GOALS • Each site should evaluate implementation of this process • Survey workers regarding their questions or concerns • Identify lessons learned for implementation • Study accident trends associated with breaker operations

QUESTIONS?