Case Study: CDM Smith improves generator brush maintenance safety with ETAP DC Arc Flash analysis

CDM Smith quantifies DC arc flash hazard with ETAP, including ~6 cal/cm² field discharge energy

CDM Smith, a global engineering and construction firm, faced significant safety risks while performing maintenance on energized generator brush and collector ring assemblies. The challenge was the lack of any recognized DC arc flash standard to quantify the incident energy and determine proper personal protective equipment (PPE), exposing workers to severe hazards from two independent DC energy sources during a fault.

ETAP addressed this by combining its Transient Stability and DC Arc Flash modules to accurately model the generator's field discharge and the exciter's contribution. Using methods like IE subtraction, ETAP provided a realistic estimate of the total incident energy, which was calculated to be approximately 6.43 cal/cm². This enabled CDM Smith to better select PPE and develop safer maintenance practices in the absence of formal standards, significantly mitigating worker risk.

CDM Smith