Understanding Arc Flash Safety Compliance
What is an Arc Flash?
An arc flash occurs when short circuit current flows across a gap creating an arc and can be anything from minor embarrassing sparks to a deadly explosion.
The Arc Flash is usually caused by accidental contact between energized conductors from events such as dropping a screw driver or touching a wire. It can produce temperatures in the thousands of degrees, create extreme blast pressure, launch projectiles at hundreds of miles per hour, produce ultra-violet light that can blind. It can and does kill people!
The IEEE 1584 Working Group has been studying the effects of Arc Flash through testing and analysis which lead to the development of: IEEE Std.1584tm, IEEE Guide for Performing Arc Flash Hazard Calculations which defines formulas and procedures used to calculate the amount of incident energy that can be released during and arcing short circuit.
What Does OSHA Say About Arc Flash?
According to OSHA 1910.132(d) the employer is responsible to assess the hazards in the work place, select, have, and use the correct Personal Protective Equipment (PPE) and document the assessment. The use of NFPA 70E and other related industry consensus standards has been used to demonstrate whether an employer acted reasonably when there is a possible OSHA enforcement action taken.
So although NFPA 70E is not directly part of OSHA standards, it can be used as evidence of whether an employer acted reasonably in complying with OSHA standards and addressing “recognized hazards”.
There are more specific links within the OSHA standards as well. A typical example is found in 1910.335, Safeguards for personnel protection which requires:
“(a)(1)(i) Employees working in areas where there are potential electrical
hazards shall be provided with, and shall use, electrical protective equipment
that is appropriate for the specific parts of the body to be protected and for
the work to be performed.
This regulation requires that employees must be properly protected from potential electrical hazards, by using adequate PPE, but it does not provide specific detail of what specific personal protective equipment is necessary to achieve the objective. It might be considered that based on this generalized statement, the selection of the correct PPE is open to interpretation however, this would be incorrect and an Arc Flash study should be performed. NFPA 70E defines many of the methods.”
NFPA 70E and Arc Flash
NFPA 70E Section 130.3(B) requires that an Arc Flash Hazard analysis
shall determine, and the employer shall document, the incident energy exposure of the worker (in calories per square centimeter). The incident energy exposure level shall be based on the working distance of the employee’s face and chest areas from a prospective arc source for the specific task to be performed. It further states that …flame-resistant (FR) clothing and personal protective equipment (PPE) shall be used by the employee based on the incident energy exposure associated with the specific task.”
NFPA 70E compliance also requires determining the arc flash protection boundary, which is the distance from a potential arc source where the incident energy falls to a value of 1.2 cal/cm2. This value is considered to be the point at which the onset of a second-degree burn occurs. Live work performed outside of the flash protection boundary does not require PPE, although the risk of some injury still exists.
The concept of these requirements is simple. At each location, the arc flash study is used to determine:
- The incident energy exposure for a worker’s chest and face if an arc
flash occurs.
. The level of PPE a worker must wear based on The possible incident energy exposure.
. The arc flash protection boundary.
NFPA 70E provides generalized hazard risk tables that can be used as a simplified alternative for PPE selection. This information, as well as data regarding electric shock protection and approach limits, is used as part of an electrical safety program.
Before conducting live work, a qualified worker must perform the shock hazard and flash hazard analysis that NFPA 70E requires.
Jim Phillips, P.E. is a member of the IEEE 1584 Working Group “Guide for Performing Arc Flash Hazard Calculations” and has developed 26 electrical training programs based on his vast experience with electrical utilities, large industrial companies and government agencies. Read more about Jim’s arc flash training courses, including How to Perform an Arc Flash Study Article Source:http://www.articlesbase.com/management-articles/understanding-arc-flash-safety-compliance-1496914.html
Share this:
Read also:
- Achieve your Objectives with Effective Seminar Management
- Consulting Clients: How to Get Them - Using Your Network and Offline Methods
- Effective Policy Making and Business Management
- Finding a Quality Small Business Management Online Company
- Why Some Small Businesses Fail to Grow
- How to protect a partnership in the recession by using a Partnership Arrangement