CRB Mission Critical Newsletter / Edition 1


	Today more than ever, many companies are becoming "financially painfully" aware of the dangers associated with an arc flash explosive incident. They are employing procedures to protect their employees against possibly fatal burns that can result from an arc flash incident. NFPA statistics report that an arc flash recordable event can occur as often as every 10 minutes in the United States. Since coming to work at CRB , I have been given the latitude to write or speak about topics that are important to me as it pertains to my mission critical role. Having lost a friend a few years ago to an arc flash explosive event, I have chosen to write my first CRB newsletter to help businesses understand the challenging process of developing and enforcing an arc flash safety program. CRB has a concise understanding of this process and can be relied on to help with this task. If you have questions after reading this article, I'd be happy to talk with you about your arc flash protection program and how we can help. Sincerely, Tom Brink Global Director, Mission Critical Facilities tom.brink@crbusa.com 816-880-9800

	An arcing fault is the flow of current through air between phase conductors or a phase conductor and a grounded conductor. An arcing fault can release large amounts of radiant energy at the point of the arc in a few milliseconds resulting in extremely high temperatures, a tremendous pressure blast and potential shrapnel moving at a high velocity. Arc flash protection was first requested for personnel safety in 2002. Arc flash labels can now be seen on most major power distribution equipment in large industrial and commercial facilities. Arc flash labeling is derived from accurate calculations performed by an electrical engineer. The 2009 edition of NFPA 70E, Electrical Safety in the Workplace, requires labels to include the required level of personal protective equipment (PPE) to be worn for servicing that specific piece of equipment energized and the available incident energy with a limited approach distance for unprotected personnel. Arcs can be initiated by a variety of causes. At all times when an arc flash can occur, the electrical equipment is energized. Sometimes an arc flash can occur when a worker thinks the equipment is de-energized. Other occurrences can happen when a worker accidentally creates a fault condition with a tool in the energized panel. Dust, water and other contaminates can accumulate over time and aid in the deterioration and breakdown of insulation or create a direct fault that results in an arc. Exposure to an arc flash frequently results in a variety of serious injuries and, in some cases, death. Workers can be injured even if they are several feet away from the arc center. Worker injuries can include damaged hearing, damaged eyesight, and severe burns. Incident energy is expressed in calories per cubic centimeter squared (cal/cm2). An arc fault can result in extensive equipment damage resulting in an extended downtime period and expensive repairs or replacement. Dependent upon the facility type and its specific operations, arc fault damage can result in significant delays or loss of production time, ultimately leading to a loss of revenue. In the event someone should be injured in an arc fault accident, the cost of treatment for the injured worker can exceed $1,000,000 per case. Significant litigation fees, insurance increases, fines and accident investigation costs can occur. Preventive maintenance, worker training and an effective safety program can significantly reduce arc flash exposure. Preventive maintenance should be conducted on a routine basis to ensure safe operation. As part of a preventive maintenance program, equipment should be thoroughly cleaned and routine inspections should be conducted by qualified personnel who understand how to uncover loose connections, overheated terminals, discoloration of nearby insulation and pitted contacts.
	Safety Programs An electrical safety program must be established for every facility using facility specific information. If the work cannot be performed concurrently, the safest way to perform maintenance and repairs on electrical equipment is to perform this work only when the equipment is de-energized. The fact that many facilities operate 24/7 sometimes does not make that possible. Therefore the electrical safety program must enforce procedures to address the hazards of working on energized equipment. PPE must be worn when any work is conducted on energized equipment within the flash protection boundary for that equipment. The discipline of an electrical safety program should be to remove the electrician from an electrical hazard and eliminate the possibility of an arc flash.
	Hazard Analysis An arc flash hazard analysis defines the flash protection boundary distance and the PPE required for working on energized circuitry. An arc flash study requires a great attention to detail. During a study, the following items are addressed specifically: • Due diligence to determine electrical system and installation data • Define equipment modes of operation/automation • Calculate bolted fault current • Provide proper protective device characteristics • Record system voltages and equipment classification • Calculate arc fault current • Define the safe working distances • Calculate the incident energy (cal/cm2) • Find Protective Device Characteristics and Duration of Arcs An arc flash hazard analysis provides up-to-date equipment information, load capacities, short circuit studies, protective device coordination studies and equipment evaluations to determine that the current ratings are correct, safe and as designed. For facilities with backup generators, a fault coordination study should also be performed. This analysis will provide incident energy calculations and arc flash boundaries for each location in a specific power distribution network. Warning labels and safety programs can then be put into action. Tables and guidelines for calculating incident energy are available in NFPA 70E, with more detailed calculations in IEEE 1584. Engineering decisions might include replacing switchgear with arc flash resistant technology, adding a secondary main trip relay, or replacing incorrect fuses. Procedures for remote racking and operation of motorized circuit breakers should be up-to-date and available. Accurate incident energy levels are vital in setting the level of proper PPE required for work within the flash protection boundary. About 5-7% of all workplace injuries and deaths are related to electrical equipment. Arc flash incidents are responsible for a significant portion of these deaths and injuries. Arc flash dangers such as shock, electrocution, and arc blast will always be present, but proper awareness, training and the development of arc flash safety personal protection strategies can minimize the likelihood of injury and fatality. Businesses cannot afford to ignore the safety issues surrounding arc flash incidents. The Occupational Safety & Health Administration (OSHA) enforces new standards for employee safety protection in potential arc flash situations. Arc flash studies began in the early 1980s to take steps to establish best practices to protect employees working on electrical equipment. Since then, this work has continued with OSHA, NFPA and IEEE. Now companies are required to perform an arc flash hazard analysis to determine flash protection boundaries and appropriate PPE for employees. Electrical equipment with potential for arc flash must be marked with a warning label with facility equipment specific information. It is the responsibility of the facility owner, not the manufacturers, to provide the arc flash calculations and appropriate labels for equipment in the facility.
	Industry Safety Standards Four main regulating standards exist for arc flash calculations and evaluations. They are as follows: • OSHA Standards 29-CFR, Part 1910. • (NFPA) Standard 70. “The National Electrical Code” (NEC) • NFPA 70E • The Institute of Electronics and Electrical Engineers (IEEE) 1584 CRB has qualified staff who can assist you in performing an arc flash study. If you would like additional information, please contact Brad Watford at brad.watford@crbusa.com, Dan Boresch at dan.boresch@crbusa.com, or myself at tom.brink@crbusa.com.