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At least 19 records

Changing An Electrical Safety Culture - The Importance of Understanding Why.

Abstract – Electrical workers, regardless of experience, are faced with a major barrier when first introduced to NFPA 70E, “The Standard for Electrical Safety in the Workplace,” and an erroneous electrical safety culture pre-exists. This paper describes, from the author’s point of view, the barrier that he and other electrical workers have experienced and his insight into overcoming the barrier. The author in conclusion will present a series of techniques that can be used to assist other electrical workers in overcoming the barrier.

Barrier↗

Electrical Safety Program: Nonelectrical Crafts at LANL, Live #12175

Los Alamos National Laboratory (LANL) and the federal government require those working with or near electrical equipment to be trained on electrical hazards and how to avoid them. Although you might not be trained to work on electrical systems, your understanding of electricity, how it can hurt you, and what precautions to take when working near electricity could save you or others from injury or death. This course, Electrical Safety Program: Nonelectrical Crafts at LANL (12175), provides knowledge of basic electrical concepts, such as current, voltage, and resistance, and their relationship to each other. You will learn how to apply these concepts to safe work practices while learning about the dangers of electricity—and associated hazards—that you may encounter on the job. The course also discusses what you can do to prevent electrical accidents and what you should do in the event of an electrical emergency. The LANL Electrical Safety Program is defined by LANL Procedure (P) 101-13. An electrical safety officer (ESO) is well versed in this document and should be consulted regarding electrical questions. Appointed by the responsible line manager (RLM), ESOs can tell you if a piece of equipment or an operation is safe or how to make it safe.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Designing Crane Controls with Applied Mechanical and Electrical Safety Features

The use of overhead traveling bridge cranes in many varied applications is common practice. In particular, the use of cranes in the nuclear, military, commercial, aerospace, and other industries can involve safety critical situations. Considerations for Human Injury or Casualty, Loss of Assets, Endangering the Environment, or Economic Reduction must be addressed. Traditionally, in order to achieve additional safety in these applications, mechanical systems have been augmented with a variety of devices. These devices assure that a mechanical component failure shall reduce the risk of a catastrophic loss of the correct and/or safe load carrying capability. ASME NOG-1-1998, (Rules for Construction of Overhead and Gantry Cranes, Top Running Bridge, and Multiple Girder), provides design standards for cranes in safety critical areas. Over and above the minimum safety requirements of todays design standards, users struggle with obtaining a higher degree of reliability through more precise functional specifications while attempting to provide "smart" safety systems. Electrical control systems also may be equipped with protective devices similar to the mechanical design features. Demands for improvement of the cranes "control system" is often recognized, but difficult to quantify for this traditionally "mechanically" oriented market. Finite details for each operation must be examined and understood. As an example, load drift (or small motions) at close tolerances can be unacceptable (and considered critical). To meet these high functional demands encoders and other devices are independently added to control systems to provide motion and velocity feedback to the control drive. This paper will examine the implementation of Programmable Electronic Systems (PES). PES is a term this paper will use to describe any control system utilizing any programmable electronic device such as Programmable Logic Controllers (PLC), or an Adjustable Frequency Drive (AID) 'smart' programmable motion controller. Therefore the use of the term Programmable Electronic Systems (PES) is an encompassing description for a large spectrum of programmable electronic control devices.

Lytle, Bradford P.↗

Electrical Safety Practices Developed for Automotive Lithium Ion Battery Dismantlement

ORNL is developing electrical safety practices for handling and disassembling automotive lithium ion batteries in a research environment. Online literature searches did not reveal any standard electrical safety practices for disassembling lithium ion battery stacks from automobiles. Until recently, there has been insufficient motivation to recycle or refurbish spent automotive lithium ion batteries due to limited volumes entering the secondary market. However, a growing volume of spent lithium ion batteries are beginning to collect in automobile salvage yards, recycling facilities, landfills, and other places due to a shortage of economically and environmentally viable end-of-life options. ORNL studied automotive battery pack, module, and cell dismantlement to understand the risks, hazards, and controls necessary to perform dismantlement safely and economically. Packs, modules, and cells were manually taken apart, while wearing appropriate personal protective equipment, with insulated hand tools. These dismantlement studies point out the hazards and risks associated with dismantling automotive lithium ion batteries and describe practices for controlling such hazards and risks while demonstrating the controls through a case study of a first-generation Chevrolet Volt battery pack.

25 ENERGY STORAGE↗

Electrical safety for high voltage arrays

A number of key electrical safety requirements for the high voltage arrays of central station photovoltaic power systems are explored. The suitability of representative industrial DC power switchgear for control and fault protection was evaluated. Included were AC/DC circuit breakers, electromechanical contactors and relays, load interruptors, cold disconnect devices, sectionalizing switches, and high voltage DC fuses. As appropriate, steady state and transient characteristics were analyzed. Failure modes impacting upon operation and maintenance safety were also identified, as were the voltage withstand and current interruption levels.

Marshall, N. A.↗

R&D DC Electrical Safety [Slides]

Objectives: Recognize DC and pulsed electrical hazards; Improve risk assessment skills; Concepts to improve worker safety; Engineered vs. administrative controls; tools of the trade.

42 ENGINEERING↗

Electrical safety requirements: Implications for the module designer

Commercial photovoltaic array installations, which include residential and intermediate applications, are subject to building and electrical codes and to product safety standards. The National Electrical Code (NEC) Article 690, titled Solar Photovoltaic Systems, contains provisions defining acceptable levels of system safety and emphasizes the system design and its installation. The Underwriters Laboratories, Inc. (UL), document titled: Proposed First Edition of the Standard for Flat Plate Photovoltaic Modules and Panels, UL-1703, identifies module and panel construction requirements that ensure product safety. Together these documents describe requirements intended to minimize hazards such as shock and fire. Although initial focus of these requirements is on single crystal silicon modules, they are generic in nature, and are equally applicable to high voltage ( 30 Vdc), multikilowatt, thin film systems. A major safety concern is insulation breakdown within the module or array wiring system, or discontinuities within the electrical conductors. These failures can result in ground faults, in circuit arcs, or exposure to hazardous electrical parts. Safeguards are discussed.

Sugimura, R. S.↗

Offshore Wind Electrical Safety Standards Harmonization (Workshop Proceedings)

Offshore wind (OSW) development activity is accelerating in the United States, with over 10 gigawatts (GW) of capacity likely to be installed on the Atlantic coast before 2030. In addition, states have committed to procure over 29 GW of offshore wind. Experienced European offshore wind energy developers are beginning to make large investments into offshore wind projects in American waters, and some U.S. developers have submitted key design documents for regulatory review. European offshore wind developers possess extensive experience in other geographic markets, which greatly increases confidence that the U.S. offshore wind industry will be successful. Nonetheless, existing U.S. electrical standards and European electrical standards are significantly different. If not addressed, these differences could potentially impact worker safety.

17 WIND ENERGY↗

Clarkson Facility Electrical Safety

Anybody can design a system that works. Our mission is to design a system that, when it fails, will fail in an orderly manner that will result in a minimum of injury or loss of life There is no such thing as “safe,” or “working safely.”

42 ENGINEERING↗

Solid-state Architecture Batteries for Enhanced Rechargeability and Safety for Electric Aircraft

All electric vertical take-off and landing vehicles (eVTOL) for urban air mobility (UAM) concepts face numerous challenging technical barriers before their introduction into the consumer marketplace. The most challenging of these technical barriers to overcome is developing an energy storage system capable of meeting the rigorous aerospace safety and performance criteria. The performance metrics for eVTOL craft are at least 2 times greater than those of electric automobiles. Furthermore, safety is essential for operation of commercial electric aerovehicles. Preliminary systems level analysis has indicated that there are five key properties which must be optimized for successful implementation of battery systems. Those five key criteria are: safety, energy density, power, packaging design and scalability. Current state-of-the-art (SOA) lithium-ion batteries meet or exceed the requirements for electric aviation in the areas of power and scalability, yet are insufficient in the key performance criteria of energy, safety and packaging design. The SABERS concept proposes a battery that meets all five key performance criteria through development of a solid-state architecture battery utilizing high energy density and power density sulfur-selenium cathode with a lithium metal anode. The combination of sulfur and selenium offers a balanced energy-to-power density ratio, which can be tailored to the specific application by altering the stoichiometric ratios of sulfur to selenium. This cathode will be developed by implementing NASA patented holey graphene technology as a highly conductive, ultra-lightweight electrode scaffold. A solid-state electrolyte will be used as a safe, non-flammable replacement to the highly flammable liquid organic electrolytes currently used in SOA lithium-ion batteries. This solid-state lithium-sulfur-selenium cell will be designed into a serial stacking configuration to enable dense packaging of the battery cells. The serial stacking configuration is termed a bipolar stack, which has the advantages of reducing overall cell weight, reducing the amount of interfaced connections for the cell, and minimizing the cooling requirements for the cell. Lastly, optimization of battery components will occur through a robust and rigorous combination of various computational modeling techniques covering multiple length scales. The expected result will be a fully solid-state battery with operational temperatures from 0 °C to 150 °C which provides the required energy density, discharge rates, and inherent safety to meet the strict aerospace performance criteria. This presentation will show initial results that demonstrate the SABERS Team has developed a composite carbon-sulfur cathode which exceeds 1100 Wh/kg at a discharge rate of 0.4C, and 804 Wh/kg at a discharge rate of 1C. Additionally, this presentation will show the SABERS Team multiscale computational modeling approach and has produced a novel particle dynamics method called Solid Electrolyte Sphere Approximation Model (SESAM). SESAM is on the 1-10 µm scale and provides electromechanical and grain interactions for predictive design guidelines for the experimental team to follow.

Urban Air Mobility (UAM) Vehicles↗

Computational Modeling Development of Solid-state Architecture Batteries for Enhanced Rechargeability and Safety for Electric Aircraft

All electric vertical take-off and landing vehicles (eVTOL) for urban air mobility (UAM) concepts face numerous challenging technical barriers before their introduction into the consumer marketplace. The most challenging of these technical barriers to overcome is developing an energy storage system capable of meeting the rigorous aerospace safety and performance criteria. The performance metrics for eVTOL craft are at least 2 times greater than those of electric automobiles. Furthermore, safety is essential for operation of commercial electric aerovehicles. Preliminary systems level analysis has indicated that there are five key properties which must be optimized for successful implementation of battery systems. Those five key criteria are: safety, energy density, power, packaging design and scalability. Current state-of-the-art (SOA) lithium-ion batteries meet or exceed the requirements for electric aviation in the areas of power and scalability, yet are insufficient in the key performance criteria of energy, safety and packaging design. The SABERS concept proposes a battery that meets all five key performance criteria through development of a solid-state architecture battery utilizing high energy density and power density sulfur-selenium cathode with a lithium metal anode. The combination of sulfur and selenium offers a balanced energy-to-power density ratio, which can be tailored to the specific application by altering the stoichiometric ratios of sulfur to selenium. This cathode will be developed by implementing NASA patented holey graphene technology as a highly conductive, ultra-lightweight electrode scaffold. A solid-state electrolyte will be used as a safe, non-flammable replacement to the highly flammable liquid organic electrolytes currently used in SOA lithium-ion batteries. This solid-state lithium-sulfur-selenium cell will be designed into a serial stacking configuration to enable dense packaging of the battery cells. The serial stacking configuration is termed a bipolar stack, which has the advantages of reducing overall cell weight, reducing the amount of interfaced connections for the cell, and minimizing the cooling requirements for the cell. Lastly, optimization of battery components will occur through a robust and rigorous combination of various computational modeling techniques covering multiple length scales. The expected result will be a fully solid-state battery with operational temperatures from 0 °C to 150 °C which provides the required energy density, discharge rates, and inherent safety to meet the strict aerospace performance criteria. This presentation will show initial results that demonstrate the SABERS Team has developed a composite carbon-sulfur cathode which exceeds 1100 Wh/kg at a discharge rate of 0.4C, and 804 Wh/kg at a discharge rate of 1C. Additionally, this presentation will show the SABERS Team multiscale computational modeling approach and has produced a novel particle dynamics method called Solid Electrolyte Sphere Approximation Model (SESAM). SESAM is on the 1-10 µm scale and provides electromechanical and grain interactions for predictive design guidelines for the experimental team to follow.

Urban Air Mobility (UAM) Vehicles↗