Installation and Application Considerations of Arc Resistant Medium Voltage Control Equipment

Abstract

Improved medium voltage (MV) control equipment designs, including enhanced structural protection systems, have continued to evolve in support of improved personnel protection. Recent changes to some standards, such as the NFPA-70E; have emphasized the need to look for improved safety compliance to mitigating the risks associated with the operation and maintenance of electrical equipment. The requirements for employee safe work practices have all targeted reducing the risks of electrical arc hazards. However, arcs accompanied by explosions continue to occur in electrical systems. Factors such as inappropriate human interaction with the equipment, equipment malfunctions because of misuse or lack of regular maintenance or unforeseen events continue to contribute to the unexpected release of explosive electrical energy in the workplace. New arc resistant MV control equipment designs provide an additional level of protection if properly installed and applied. This paper will outline the added benefits of arc resistant equipment along with the details surrounding the appropriate installation and site application considerations when arc resistant MV control products are being considered. Also included is a case history where arc resistant medium voltage motor control equipment was installed at a production facility of a large North American chemical company.