Abstract: An intelligent electronic device is operable to use a signal derived from an electrical power delivery system to effectively detect an islanding condition. The intelligent electronic device is configured to compare a frequency deviation (from nominal frequency) and a rate-of-change of frequency of the electrical power delivery system to a protection characteristic of the intelligent electronic device to quickly and securely detect islanding conditions thereby enhancing power protection, automation, control, and monitoring performance. The intelligent electronic device uses local measurements of the electrical power deliver system to provide reliable and economical means to properly separate a generation site from the remainder of the electrical power delivery system. Such may be useful to prevent reclosing out of synchronism.