Arc flash Assessments

NFPA 70E requires an updated arc flash hazard analysis after any substantive change to a plant area's electrical system or on a periodic basis, typically every 3-5 years.  This analysis requires specific electrical engineering knowledge and access to modeling software to complete.  For these reasons, companies typically rely on power study providers for this analysis. 

 A complete power study/arc flash analysis includes the following deliverables: 

• Short Circuit Study 

  • Calculated fault currents  

  • Equipment interrupting ratings 

  • Recommendations for any under-rated devices 

• One-line Impedance Diagram 

  • Electrical one-line diagram format 

  • Transformer KVA, voltage, impedance ratings 

  • Circuit X/R rations and short circuit values 

  • Feeder sizes and lengths 

  • Utility contribution 

  • Motor horsepower 

• Protective Device Coordination Study 

  • List of protective devices with relevant device data 

  • Plotted time-current curves 

  • Determination of correct settings for fuses, circuit breakers, and protective relays 

• Arc Flash Study 

  • Determination of incident energy, arc flash boundary, and PPE requirements for panelboards and switchboards 

  • ANSI compliant color coded arc flash warning labels