As used in this chapter, unless the context otherwise clearly requires:

1.    “Electrical supply lines” shall mean those electrical conductors and their necessary supporting and containing structures which are used for transmitting a supply of electrical energy.

2.    “Operation” shall be construed and applied only in relation to the manner of operating the lines referred to so as to avoid or minimize the hazard of injury to persons or property and to avoid or mitigate interference with the service of signal lines.

3.    “Signal lines” shall mean those lines for public or private signal or communication service and devoted exclusively to the transmission of signals or intelligence which operate at not more than four hundred volts to ground or seven hundred fifty volts between any two points of the circuit and the transmitted power of which does not exceed one hundred fifty watts.