Southern New England Telephone Co. in New Haven, CT, has deployed a fiber-optic network architecture that has power conductors around fiber-optic lines. The system features a steel armor sheath and extra installation that shields the electricity and provides protection against possible cable breaks. It does not depend on the local power grid, nor does it rely on structures containing lead-acid batteries or noisy generators. The cable may carry 480 volts alternating current from the central office to the local nodes where fiber lines connect to coaxial cables. These coaxial cables carry the same low-power current as telephone lines. Electrical power company lines typically carry more than 13,000 volts.