NEMA PB 2.2-2014包含GFP设备的安全和正确应用说明。GFP装置包括电流传感装置、继电器设备或电流传感装置和继电器设备的组合，或其他等效保护设备，其操作将导致断开装置以预定的接地故障电流和时间值断开所有未接地导体。

NEMA PB 2.2-2014 contains instructions for the safe and proper application of GFP devices. GFP devices include current-sensing devices, relaying equipment or combinations of current-sensing devices and relaying equipment or other equivalent protective equipment that will operate to cause a disconnecting means to open all ungrounded conductors at predetermined values of ground-fault current and time.