This standard describes requirements for power line carrier (PLC) transmitter/receiver equipment used to transfer discrete teleprotection signals at power-line-carrier frequencies (30-500 kHz). Test requirements and conditions for determining performance, as well as manufacturing requirements, are defined. This standard does not include broadband or single sideband (SSB) power line carrier equipment used for data transmission, nor does it include terminal equipment used on distribution circuits for the purpose of load management or automation.