IEC Corporation conducted an arc flash analysis study for the Macho Springs Wind Project, Phase 1 collection system and substation and for the project switchyard. The purpose of the analyses was to address electrical safety requirements that were necessary for the safeguarding of personnel during maintenance or exposure to live electrical equipment. To complete the study, IEC modeled the system single line and all electrical components using SKM Power Tools version 6.5.2.5 (Build 4). A single line model of the wind farm collection system and substation was completed using client-supplied drawings as a reference.

Equipment and device ratings used in the model were based on wind farm and substation approved equipment manufacturer drawings and data sheets. IEC performed simulations to determine system bolted fault currents, arc fault currents, duration of faults, and incident arc fault energy for all relevant equipment. The model output data was then used to determine arc flash category, flash hazard boundary and equipment boundary approach. IEC generated arc flash warning labels containing these values for each piece of equipment and provided labels to the client.

The resulting client report identified electrical arcing hazard potential according to the arc flash regulations of NFPA 70E (Standard for Electrical Safety in the Workplace) and IEEE 1584 (Guide for Performing Arc-Flash Hazard Calculations). The results detailed requirements for the proper Personal Protective Equipment (PPE) that were required to be worn by qualified personnel to operate and work on live electrical equipment. The report also included: Single Line drawings (developed for modeling the system in SKM software and an enlarged view of wind turbine model), Arc flash summary report, Protective Device and Bus Arc Flash Safety Labels, Nacelle Enclosure Arc Flash Safety Labels, Protective Device and Bus Arc Flash Safety Labels, Personal Protective Equipment Table, and Work Permits.