The National Electrical Manufacturers Association (NEMA) recently published NEMA WD-AG 1-2017 Application Guide for Isolated Ground Wiring Devices to include new requirements under the 2017 National Electrical Code (NEC). This revision also covers wiring devices and accessories intended to help protect sensitive equipment from malfunction due to electrical noise on the equipment grounding path.
According to David Lutz, chairman of the Wiring Devices Technical Committee, “Isolated ground devices have been around for many years, but their use and installation continue to be misunderstood. This guide is a resource for the correct and safe use and installation of these devices, and has been updated to reflect the current NEC requirements.”
NEMA WD-AG 1 also covers applications, troubleshooting, and maintenance of isolated ground circuits. Canadian requirements were removed from the current edition and will be addressed separately in a Canadian document.
NEMA WD-AG 1-2017 is available as an electronic download at no cost on the NEMA website.