This part of IEC 61334 is applicable to MV phase-to-earth capacitive and screen-to-earth intrusive inductive coupling devices for medium voltage (MV) distribution line carrier (DLC) systems. Non-intrusive inductive coupling devices are not within the scope of this standard. The coupling device ensures a) the efficient transmission/reception of carrier-frequency signals between the DLC transceiver and the power line; b) the safety of personnel and the protection of the low-voltage parts of the installation against the effects of the power-frequency voltage and transient overvoltages. The object of this part of IEC 61334 is to establish definitions, requirements, methods of testing and rated values for phase-to-earth capacitive and screen-to-earth intrusive inductive coupling devices to be used in MV-DLC systems.