Referred to as arc eye, but also sometimes called welder's flash, bake eyes, or snow blindness, this comes from seeing the flash of the arc without the proper eye covering. Photokeratitis – an eye condition similar to sunburn but of the cornea – can cause temporary or long-term vision problems.A sound blast from the incident can be loud enough to cause eardrums to rupture, creating short- or long-term hearing problems.These droplets adhere to clothing or skin and cause deep, severe burns. This can include tools and parts, but it can also include metal that has been melted by the high temperatures, with metal droplets being propelled at high speeds from the flash itself. The explosion caused by an arc flash can propel shrapnel at high speeds.This includes lung damage, nerve damage, and potential heartbeat disruption. It requires field marking for switchboards, panelboards, industrial control panels and motor control centers. Pressure from arc flash waves has been seen to produce more than 2,000 pounds per square foot of force, enough to bruise or cause disruption to body systems and damage tissue. The concussion wave from the arc flash incident can expand quickly, throw workers across rooms, and knock them off ladders.This is hot enough to vaporize nearby objects, humans included. By comparison, the sun's surface only measures up to 9,000 degrees Fahrenheit. These are temperatures that can cause severe burns, even if the worker is ten or more feet away from the flash itself. Temperatures in an arc flash can reach as high as 35,000 degrees Fahrenheit.Available incident energy and the corresponding working distance, or arc flash PPE category in Table 130.7 (C)(15)(A)(b) or Table 130.7(C)(15)(B) for the equipment, but not both.Įxample of an Arc Flash Label containing the NFPA 70E required elements below.The 2018 NFPA 70E® goes into further detail about the labeling requirements in Article 130.5 (H) Equipment Labeling:Įlectrical Equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centers that are in other than dwelling units and are likely to require examination, adjustment, servicing, or maintenance while energized shall be marked with a label containing the following information: The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing, or maintenance of the equipment."Įquipment labeling is the responsibility of the employer when any electrical equipment must require examination, adjustment, servicing, or maintenance while energized. "Electrical Equipment, such as switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures, and motor control centers that is in other than dwelling occupancies and is likely to require examination, adjustment, servicing, or maintenance while energized shall be field marked or factory marked to warn qualified persons of potential electric arc flash hazards. What are the equipment labeling requirements?Įquipment labeling requirements are detailed in both the National Electrical Code (NEC) NFPA 70® as well as in the 2018 NFPA 70E®. Of these three organizations, NFPA provides the most comprehensive standard for safety-related work practices for employers to implement and provide a safe working area for employees relative to the hazards arising from the use of electricity. Plasma Level: Joined: Tue 4:08 pm Posts: 2178 Location: North Carolina NEC has a suggested list of what has to be marked but keep in mind that the list is a guideline and should not be read as an absolute rule. There are multiple national organizations that provide guidelines and standards on the risks and prevention of electrical related hazards in the work place. Post subject: Re: arc flash boundary markings. Exposure to these conditions burns the skin directly, may cause a variety of serious injuries and can even result in death. The temperatures can reach as high as 35,000☏. An Arc Flash is an electric current passing through air between ungrounded conductors or between ungrounded conductors and grounded conductors resulting in an explosive burst of heat, light and a pressure wave.
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