Arc Flash Protection personal equipment
Personal protective equipment, or PPE is designed to protect employees from serious workplace injuries or illnesses resulting from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards. Besides face shields, safety glasses, hard hats, and safety shoes, Personal protective equipment, or PPE includes a variety of devices and garments such as goggles, coveralls, gloves, vests, earplugs, and respirators.In order to select the proper PPE, incident energy must be known at every point where workers may be required to perform work on energized equipment. These calculations need to be performed by a qualified person such as an electrical engineer. All parts of the body that may be exposed to the arc flash need to be covered by the appropriate type and quality of PPE. Proper PPE can include Flame Resistant clothing, helmet or headgear, face shield, safety glasses, gloves, shoes, etc. depending upon the magnitude of the arc energy.
What is my risk to being exposed to arc flash? The exposure to arc flash depends on the following:
Number of times the workers perform a task involving exposed live equipment Complexity of the task performed, need to use force, available space, safety margins, reach, etc. Training, skills, mental and physical agility, coordination with helper Tools used Condition of equipment Exposure to an arc flash frequently results in a variety of serious injuries and in some cases death. Workers have been injured even though they were ten feet or more away from the arc center. Worker injuries can include damaged hearing, eyesight, and severe burns requiring years of skin grafting and rehabilitation.
Equipment can be destroyed causing extensive downtime and requiring expensive replacement and repair. The cost of treatment for the injured worker can exceed $1,000,000/case. This does not include very significant litigation fees, insurance increases, fines, accident investigation, etc. This also does not include process loss to the employer.
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.
A comprehensive preventive maintenance plan should also include:
Using corrosion resistant terminals and insulate exposed metal parts if possible
Sealing all open areas of equipment to ensure rodents and birds cannot enter Verifying that all relays and breakers operate properly
Arc Flash first became popular in the early 1980's with the publication by Ralph Lee titled, "The Other Electrical Hazard: Electric Arc Blast Burns." Similar studies illustrated that too many people were suffering injuries as a result of arc flash incidents. Therefore, early adopters in the petrochemical industry took steps to establish the first set of practices designed to better protect employees and electrical contractors. Soon other industries recognized the need for additional protection against arc flash hazards. These new industry standards developed by the NEC and others were designed to keep electrical workers free from the hazards of shock, electrocution, arc flash, and arc blast.
There are four main regulations governing arc flash.
They include:
OSHA Standards 29-CFR, Part 1910. Occupational Safety and Health Standards. 1910 sub part S (electrical) Standard number 1910.333 specifically addresses Standards for Work Practices and references NFPA 70E.
The National Fire Protection Association (NFPA) Standard 70 - 2002 "The National Electrical Code" (NEC) contains requirements for warning labels.
NFPA 70E 2009 provides guidance on implementing appropriate work practices that are required to safeguard workers from injury while working on or near exposed electrical conductors or circuit parts that could become energized.
The Institute of Electronics and Electrical Engineers (IEEE) 1584 - 2002 Guide to Performing Arc-Flash Hazard Calculations.
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