Osborn Engineering was awarded an Arc Flash study project for Great Lakes Water Authority (GLWA). In partnership with GLWA, Osborn surveyed the existing electrical infrastructure for 39 sites located throughout Southeastern Michigan. The survey includes incoming DTE utility services ranging from 4.8 kV to 120 kV, transformers, switchgear, generators, substations, transfer switches, switchboards, motor control centers and panel boards.

The existing site information was used to develop a power system model in SKM Power Tools software to analyze the system. A comprehensive short circuit study and equipment evaluation study was completed to identify any potential deficiencies in the equipment to handle a possible short-circuit current. An overcurrent protective device study was prepared for selected devices to confirm existing device coordination and provide recommendations for setting revisions to improve system reliability. Finally, multiple scenarios were evaluated to calculate the incident energy and associated Personal Protective Equipment (PPE) requirements at each point in the electrical power system. The results of the arc flash incident energy study were used to print ANSI compliant arc flash labels for the electrical infrastructure included in the study.

The power system models and reports were prepared per NFPA 70E (National Fire Prevention Association-Standard for Electrical Safety in the Workplace) recommended practices for Arc Flash Studies. The report and labeling provided by this analysis is an integral tool for the safety and well-being of GLWA maintenance personnel and contractors who work on these power systems.