California Code, Public Utilities Code - PUC § 8030

No person shall run, place, erect, or maintain any guy wire or guy cable attached to any pole or appliance to which is attached any wire or cable used to conduct electricity, without causing the guy wire or guy cable to be effectively insulated at all times at a distance of not less than four (4) feet nor more than eight (8) feet (measured along the line of the wire or cable) from the upper end thereof, and at a point not less than eight (8) feet vertically above the ground from the lower end thereof. Where two or more guy wires or guy cables are attached to the same pole and same anchorage pole there shall be at least one foot, vertical space, between the points of attachment. No insulation shall be required at the lower end of a guy wire or guy cable where it is attached to a grounded anchor. Where guy wires or guy cables are attached to a pole or structure of steel or other conducting material supporting wires or cables conducting in excess of 15,000 volts where the pole or structure is thoroughly grounded no insulation shall be required at any point in the guy wire or guy cable.

This section does not apply to guy wires or guy cables attached to poles carrying no wire or cable other than signal wires or cables and which are situated outside the corporate limits of a city.