This international product family standard applies to transformers, reactors and power supply units covered by the IEC 61558 series of standards. This standard deals with the electromagnetic compatibility requirements for emission and immunity within the frequency range 0 Hz - 400 GHz. No test need to be performed at frequencies where no requirements are specified. Transformers, reactors and power supply units delivered with or incorporated in an appliance or equipment have to follow the relevant EMC standard applicable to that appliance or equipment. However, this standard may be used as a guide to test the transformers, reactors and power supply units separately before incorporating them in the appliance or equipment. This EMC standard covers performance only. Other operations of the transformers, reactors and power supply units (e.g. simulated faults in the electric circuitry for testing purposes or functional safety due to the effects of the electromagnetic phenomena, or evaluation of human being for exposure to electromagnetic fields (EMF)) have not been taken into consideration in this standard. Requirements are specified for each port considered. If requirements are in conflict the most severe takes precedence. NOTE When EUT (Equipment under test) is used, it covers transformers, reactors and power supply units where applicable. This standard does not apply to: uninterruptible power supplies (UPS) covered by IEC 62040; power supply units covered by IEC 61204, (i.e. DC-DC converters, DC power and distribution equipment and power supply units for use in applications covered by IEC 60950-1, IEC 61010-1, IEC 60601-1 and IEC 60065); power supplies and converters for use with or in products covered by IEC 61347.