Multichannel carrier-current facilities for a power line

A carrier-current system providing a relatively large number of channels is in service on a high-voltage power line. The facilities provide: 1. Transmission of signals both ways for the opening of the circuit breakers at the remote end by the operation of relays at the near end. 2. Two-way telephone service between any extension telephone at the remote generating station and any telephone connecting to the main telephone switchboard in the central office building. 3. Two-way telemetering (station generation one way and system total generation the other way). 4. Transmission from the systetai operator's office to the station of automatically generated load-control signals used to increase or decrease automatically the station generation. 5. Two channels in each direction for future requirements.