Arc Flash Phases of Completion
What is the process for performing an arc flash analysis?
HIPP performs arc flash assessments to critically analyze electrical systems, identify potential hazards, and provide recommendations to mitigate the risk of an arc flash incident using the following arc flash analysis process and software - highlighting the importance of complying with industry standards and regulations to ensure worker safety and proper functioning systems.
Typical steps involved in performing an arc flash study:
Project Kick-off: Prior to starting a project, we educate our clients on the project stages and update the client contact once each phase is complete.
Data Collection: The second step is a labor-intensive effort to gather electrical system information through document collection and field surveys. Field surveys are performed by qualified persons (as defined by OSHA and NFPA 70E) in appropriate PPE; preferably assisted by a qualified facility employee or someone knowledgeable of the plant electrical equipment and facility layout.
Data collected includes items such as transformer nameplates, conductor sizes / number per phase/lengths, motors larger than 50HP, circuit breaker catalog numbers and settings, fuse catalog numbers, utility metering point, and on-site generator nameplates.
Data Review: Next HIPP reviews all of the collected field data in addition to electrical system drawings such as one-line diagrams, power plans, previous arc flash reports, panel schedules, and equipment data.
Power System Modeling + One-Line Updates: Using the information gathered, the power system’s one-line diagrams are updated. This ensures the one-lines represent the actual facility power distribution system and path from the incoming power source to all loads and equipment. Next, a model of the electrical distribution system is built in a specialized electrical analysis program (SKM or Easypower) to perform the study according to IEEE 1584 +NFPA 70E standards.
Perform a short-circuit analysis: A short-circuit analysis is performed to determine the available fault current at each point in the electrical system. This analysis helps to identify potential arc flash hazards and determine the level of protective devices required to mitigate the risk as follows:
Ensure all equipment is properly rated to withstand a short circuit current
Determination of system operating modes and conditions that can impact short circuit currents and arc flash hazard energy level
Determine bolted fault current
Calculate arc fault current
Perform a protective device coordination study: A protective device coordination study is performed to ensure that the protective devices in the electrical system are properly coordinated to provide effective protection against overcurrent events. This study helps to prevent false tripping of protective devices and minimize the impact of a fault on the electrical system as follows:
Determine “Total Clearing Time” at fault currents
Determine probable sequence of which device will open during a fault
Find protective device characteristics and arc duration
Ensure electrical system reliability and determine if arc flash hazard energy levels can be reduced
Perform an arc flash analysis: An arc flash analysis is performed using specialized software to simulate possible fault scenarios and predict the level of incident energy that could be released in the event of an arc flash. The incident energy is the amount of energy that could be absorbed by a person or equipment located at a specific distance from the arc flash. The analysis is performed as follows:
Calculate Incident Energy
Calculate Arc Flash Hazard Boundaries
Determine Arc Flash Hazard / Risk Category
Specify PPE Requirements
Develop Report noting Hazards and Recommend Hazard Mitigations: A written report detailing and documenting the results from the data collection, engineering studies and recommended solutions for mitigating hazards and improving the electrical distribution system. These recommendations may include changes to the electrical system configuration, modifications to protective devices, changes to work practices, and the use of personal protective equipment (PPE). The report includes:
Inadequate Interrupting Ratings
Improper Coordination Problems
Potentially Dangerous Arc Flash Energy
Opportunities to reduce Arc Flash Hazard / Risk category level and level of PPE required.
Recommendations for improving the electrical distribution system.
Presentation and Client Review: This step includes delivery of the report and a brief presentation of the results of the engineering studies completed including Arc Flash Hazard Analysis and recommended solutions for improving the electrical distribution system. As part of collaborative presentation, the presenter will answer questions and encourage a discussion of the results and report. The report is accompanied by updated electrical one-line diagrams and electrical models on a CD.
Arc Flash + Shock Hazard Labeling: Next, our team prints and provides Labels according to NEC® and NFPA 70E requirements, informing the worker of the flash protection boundary, incident energy, work distance, required PPE level, and the shock hazard voltage and boundaries. The labels proposed will be high-quality labels, color-coded to assist the workers in determining the arc flash Hazard / Risk Category. Colors based on ANSI Z535.4 are:
Orange for H/R Category 0, 1 and 2
Red for H/R Category 3 and 4
Red “Danger” for H/R above Category 4
Each piece of equipment analyzed will have a printed arc flash hazard label with an identification number to match the equipment.
Post Arc Flash Analysis Support: Conduct training and implement recommendations: After your arc flash study is completed and labels applied, HIPP will continue to support your electrical infrastructure, safety, and arc flash program with the following services:
Updates on changes to electrical codes and standards and electrical safety practices
A best-practices program for tracking changes to your electrical system for future arc flash study and labeling updates.
Provide training program feedback as needed.