According to one embodiment, an electronic apparatus connectable to a partial power system which is a part of a power system and comprises a first power source apparatus, power supply of the first power source apparatus stopped in response to detecting an islanding of the partial power system, includes: controlling circuitry configured to output to the partial power system a first signal to disable detecting the islanding of the partial power system by the first power source apparatus during at least part of a period during which the partial power system is electrically separated from the power system.