Understanding and Quantifying Arc Flash Hazards in the Mining Industry

Arc flash generally refers to the dangerous exposure to thermal energy released by an arcing fault on an electrical power system, and in recent years, arc flash hazards have become a prominent safety issue in many industries. This problem however, has not been effectively addressed in the mining industry. MSHA data for the period 1990 through 2001 attributes 836 injuries to non-contact electric arc burns , making it the most common cause of electrical injury in mining. This paper presents results from several elements of a recent NIOSH study of arc flash hazards in mining, and provides information and recommendations that can help reduce these injuries. Characteristics of past arc flash injuries in mining are first outlined, such as the electrical components and work activities involved (based on MSHA data). This is followed by a review of important concepts and terminology needed to understand this hazard. Next, methods for identifying, measuring, and managing arc flash hazards on a power system are covered, with emphasis on recommendations found in NFPA 70E, Standard for Electrical Safety in the Workplace. Finally, results are presented from a detailed arc flash hazard analysis performed on a sample mine electrical power system using IEEE 1584-2004a, focusing on components and locations presenting severe hazards as well as engineering solutions for reducing the risk to personnel. Index terms - electrical arcing, electrical burns, mining, arc flash hazard analysis2007835

Topics in construction safety and health : contact with electricity : an interdisciplinary annotated bibliography

"These referenced articles provide literature on construction workers and their contact with electricity on the job." - NIOSHTIC-2NIOSHTIC no. 20068244Production of this document was supported by cooperative agreement OH 009762 from the National Institute for Occupational Safety and Health (NIOSH). The contents are solely the responsibility of the authors and do not necessarily represent the official views of NIOSH.Contact-with-Electricity-annotated-bibliography.pdfcooperative agreement OH 009762 from the National Institute for Occupational Safety and Healt

APPENDIX A: RAW DATA COLLECTED FROM SELECTED STUDIES

APPENDIX A: RAW DATA COLLECTED FROM SELECTED STUDIE

Safety for Particle Accelerators

The use of non-standard technologies such as superconductivity, cryogenics and radiofrequency pose challenges for the safe operation of accelerator facilities that cannot be addressed using only best practice from occupational safety in conventional industry. This book introduces readers to different occupational safety issues at accelerator facilities and is directed to managers, scientists, technical personnel and students working at current or future accelerator facilities. While the focus is on occupational safety – how to protect the people working at these facilities – the book also touches on “machine safety” – how to prevent accelerators from doing structural damage to themselves. This open access book offers a first introduction to safety at accelerator facilities. Presenting an overview of the safety-related aspects of the specific technologies employed in particle accelerators, it highlights the potential hazards at such facilities and current prevention and protection measures. It closes with a review of safety management and organization at accelerator facilities

Defining lightning-safe structures for all socio-economic communities

Four levels of lightning-safe structures are defined based on the protection expected from various lightning injury mechanisms under thunderstorm conditions. This work, therefore, provides clarification for the long-standing issue of determining the most suitable recommendation for lightning safety in various socio-economic layers of society, especially in underprivileged communities. These globally uniform and consistent guidelines will help standard development committees, lightning safety seekers and donors of protection systems, state policy developers on disaster management, the insurance sector and industries that provide lightning protection, in determining the most appropriate lightning safety measures for a given target, based on the safety requirements, societal behaviour and affordability. Significance: Lightning safety module developers could confidently adopt the definition of safe structures provided here in their guidelines. The ambiguity on both indigenous and commercial lightning safe structures (purpose made) is cleared. Standards could specify the essential features of a structure that can be considered lightning safe

PREDICTIVE MODELING OF DC ARC FLASH IN 125 VOLT SYSTEM

Arc flash is one of the two primary hazards encountered by workers near electrical equipment. Most applications where arc flash may be encountered are alternating current (AC) electrical systems. However, direct current (DC) electrical systems are becoming increasingly prevalent with industries implementing more renewable energy sources and energy storage devices. Little research has been performed with respect to arc flash hazards posed by DC electrical systems, particularly energy storage devices. Furthermore, current standards for performing arc flash calculations do not provide sufficient guidance when working in DC applications. IEEE 1584-2002 does not provide recommendations for DC electrical systems. NFPA 70E provides recommendations based on conservative theoretical models, which may result in excessive personal protective equipment (PPE). Arc flash calculations seek to quantify incident energy, which quantifies the amount of thermal energy that a worker may be exposed to at some working distance. This thesis assesses arc flash hazards within a substation backup battery system. In addition, empirical data collected via a series of tests utilizing retired station batteries is presented. Lastly, a predictive model for determining incident energy is proposed, based on collected data

Power Grid Recovery after Natural Hazard Impact

Natural hazards can affect the electricity supply and result in power outages which can trigger accidents, bring economic activity to a halt and hinder emergency response until electricity supply is restored to critical services. This study analyzes the impact of earthquakes, space weather and floods on the power grid recovery time. For this purpose, forensic analysis of the performance of the power grid during 16 earthquakes, 15 space weather events and 20 floods was carried out. The study concluded that different natural hazards affect the power grid in different ways. Earthquakes cause inertial damage to heavy equipment and brittle items, and ground failure and soil liquefaction can be devastating to electric infrastructure assets. Recovery time is driven by the balance of repairs and capabilities. Poor access to damaged facilities, due to landslides or traffic congestion, can also delay repairs. In this study, recovery time ranged from a few hours to months, but more frequently from 1 to 4 days. Floods are commonly associated with power outages. Erosion due to the floodwaters and landslides triggered by floods undermine the foundations of transmission towers. Serious, and often explosive, damage may occur when electrified equipment comes in contact with water, while moisture and dirt intrusion require time-consuming repairs of inundated equipment. Recovery time was driven by the number of needed repairs, and site access, as repairs cannot start until floodwaters have receded. In this study, power was back online from 24 hours up to 3 weeks after the flood. However, longer recovery times (up to 5 weeks) were associated with floods spawned by hurricanes and storms. Space weather affects transmission and generation equipment through geomagnetically induced currents (GICs). In contrast to earthquakes and floods, GICs have the potential to impact the entire transmission network. Delayed effects and the potential for system-wide impact were the main drivers of recovery time in this study. When damage is limited to tripping of protective devices, restoration time is less than 24 hours. However, repairs of damaged equipment may take up to several months. The study concludes with a number of recommendations related to policy, hazard mitigation and emergency management to reduce the risks of natural hazards to electric infrastructure and to improve crisis management in the aftermath of a natural disaster.JRC.E.2-Technology Innovation in Securit