ARC Flash Study
WHAT IS ARC FLASH?
An Arc Flash is a dangerous condition associated with the explosive release of energy caused by an electrical arc due to either a phase to ground or phase to phase fault.
Arc Flash occurs when the phase conductors are shorted and ionization of the air occurs. When this happens, the arc faults create large amounts of heat that can severely burn human skin and set clothing on fire. At this time molten metal is also thrown from the fault location in a radial direction potentially injuring workers. The heat during this event can reach or exceed 35,OOO°F.
WHAT DOES OSHA & NFPA SAY?
Workplace safety is governed by OSHA. OSHA has adopted the NFPA 70E as the standard for electrical safety. OSHA details the importance of electrical preventive maintenance and a
OSHA Part 1910.132(d)(1) -"The Employer shall assess the workplace to determine if hazards are present, or are likely to be present, which necessitate the use of personal protective equipment (PPE) ...."
OSHA Part 1910.132 (d)(1 )(1) -"Select, and have each affected employee use, the types of PPE that will protect the affected employee from the hazards identified in the hazard assessment; ... "
OSHA Part 1910.132(d)(2) -"The employer shall verify that the workplace hazard assessment has been performed through a written certification that: identifies the workplace evaluated; the person certifying that the evaluation has been performed; the date(s) of the hazard assessment; and which identified the document as a certification of hazard assessment."
OSHA Part 1910.335(1)(1) -"Employees working in areas where there are potential electrical hazards shall be provided with, and shall use, electrical protective equipment that is appropriate.."
NFPA 70E-2004, Part II, 2-1.3.3 states that a flash hazard analysis must be performed in order to determine the level of hazard and appropriate PPE for given tasks.
WHAT IS AN ARC FLASH LABEL?
The 2005 NEC states in Section 110.16 that "Switchboards, panel boards, industrial control panels, and motor control centers that are in other than dwelling occupancies and are likely to require examination, adjustment, servicing or maintenance while energized shall be field marked to warn qualified persons of potential electrical arc flash hazards. The marking shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicinq or maintenance of the equipment"
WHAT IS A QUALIFIED PERSON?
OSHA/70E Define a "Qualified Person" as "One familiar with the construction and operation of the equipment and hazards involved"
NFPA 70E Part II Ch. 1 1-5.4.1 " The decision-making process necessary to determine the degree and extent of the hazard and personal protective equipment and job planning necessary to perform the task safely."
This means your employees need to be trained in how to determine what levels of PPE will be needed to perform an individual task or they may not be considered "Qualified", which could restrict their access within the Flash Protection Boundary.
WHO AND WHAT DOES THIS APPLY TO?
This standard applies to Medium & High Voltage SWitchgear, Metal Clad SWitchgear. Meter Bases and Banks, Motor Control Centers, Motor Starters, Industrial Control Cabinets, Panel boards, Switchboards, Transformers, Distribution Panels, and all live Equipment over SOv.
It is enforced in Industrial, Healthcare, Education, Institutional, and Commercial Facilities.