MDS Engineering performed a comprehensive arc flash hazard analysis for 1999 K Street NW, incorporating a detailed electrical power systems study that included short circuit analysis, protective device coordination, and arc flash risk evaluation. This effort was aimed at ensuring electrical safety compliance and operational reliability for building personnel and maintenance staff.

The short circuit analysis calculated the maximum available fault currents at key points throughout the electrical distribution system. The study revealed a bolted three-phase fault current of up to 38,994 amps at the switchboard SWBD-A, and similar high fault levels at various downstream panels, which informed the basis for equipment ratings and protective device selection.

The protective device coordination study evaluated the time-current characteristics of breakers and fuses to ensure that faults are cleared selectively, without disrupting power to unaffected parts of the facility. For example, main circuit breakers in the distribution panelboards were coordinated with branch circuit breakers to maintain proper selectivity and minimize service interruptions. The study utilized time-current coordination curves to refine device settings for breakers protecting transformers, lighting panels, and HVAC equipment.

The arc flash analysis was performed under IEEE 1584 guidelines and calculated the incident energy levels and flash protection boundaries for each panel and piece of switchgear. Based on the study, some locations required PPE rated up to Category 3 (25.3 cal/cm²), with arc flash boundaries extending as far as 71 inches in areas of high fault current potential. Warning labels were generated for installation on electrical equipment, providing detailed PPE, voltage, and incident energy data to ensure compliance with NFPA 70E safety requirements.

This power systems study enabled informed decision-making for electrical maintenance planning and reduced the risk of injury due to arc flash incidents, while aligning the facility’s electrical infrastructure with applicable safety and reliability standards.