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Arc Flash Analysis

Arc_Flash

In the past 20 plus years, Arc Flash has progressed from a known but often ignored event to the fore front of electrical safety. Arc Flash was first introduced into the NFPA 70E, Standard for Electrical Safety Requirements for Employee Workplaces, Edition #5 in 1995. It introduced the concepts of limits of approach and the establishment of an arc. Subsequent editions expanded upon the establishment of arc flash boundaries and the use of personal protective equipment (PPE). In 2004, this document underwent significant changes and was renamed to NFPA 70E, Standard for Electrical Safety in the Workplace. In all of these editions, arc flash analysis and safety recommendations were focused on AC power sources. In 2012, the NFPA 70E has started to address DC systems from the informational perspective.

During a seven-year study conducted by the U.S. Dept. of Labor’s Bureau of Labor Statistics, 2,576 U.S. workers died and another 32,807 sustained lost-time injuries, missing an average of 13 days away from work due to electrical shock or burn injuries. These statistics were validated in a second study involving more than 120,000 employees that determined arc flash injuries accounted for 77% of all recorded electrical injuries. The average cost of medical treatment for survivors of arc flash incidents is $ 1,500,000. -“THE EVOLUTION OF DC IN NFPA 70E

For more information on IEEE & NFPA’s continues effort to educate others about arc flash, please see their webpage…[read more]

Why should DC Systems be evaluated? 

  • Employers should provide a safe work environment for their employees and contractors that are working on electrical systems. Part of this is to provide information regarding the hazards and required PPE necessary to minimize the risks when working on or near electrical systems.
  • Battery systems present unique hazards to personnel. Batteries do not have an “OFF” switch that can de-energize it.
  • Battery plants will respond differently to an electrical fault condition. While a faulted battery string may not initiate an arc blast, it can supply sufficient fault current to damage equipment and injure people.
  • DC arc flash safety requirements will continue to grow as more research is done on DC systems.

We can provide the following DC system analysis services:

  • DC Short Circuit – ANSI standard 399 and 946, calculates the initial rate of rise and peak fault current.
  • DC Short Circuit – IEC standard 61660, calculates the peak fault current, time constants, time to peak, and steady state conditions.

We will conduct the necessary field survey work and provide a comprehensive report for your systems.

Your DC system analysis will be performed and reviewed by a licensed professional electrical engineer. Each analysis will include a comprehensive report and appropriate labels that can be applied to your equipment. The DC analysis can be performed independently of the AC systems. Therefore, it is not necessary to perform a new AC analysis or upload an existing study.

The DC analysis can include any or all of the following components:

  • Lead-Acid Battery
  • Nickel-Cadmium Battery
  • Rectifier
  • DC Cable
  • DC Bus/Node
  • DC Load
  • DC Motor
  • Train
  • DC Generator
  • Inverter/UPS
  • DC-DC Converter
  • DC Capacitors