What are some common power quality problems confronting medical facilities?
Medical facilities, including hospitals and laboratories, face unique power quality needs because of their reliance on highly specialized and precise diagnostic and treatment equipment. These concerns extend beyond the routine power quality issues common to any operation employing electronics equipment. Three examples of specific power quality issues for medical facilities include: • Computed tomography (CT Scan) system lockup and component failurewas a repetitive problem for a medical clinic. Power to the CT Scan unit was supplied from 480-volt service fed to a 480-to-208 volt isolation transformer. Investigations identified the cause of the disturbance as a utility power factor correction capacitor bank located a block away from the clinic. The attenuation effect of the isolation transformer was not enough to protect the CT Scan system from such a severe transient. An active-tracing filter specifically designed for this type of disturbance was installed on the 480-volt line to protec
