(1) Each utility shall adopt standard nominal voltages conforming to modern usage, as may be required by the design of its distributing and transmission system for its entire service area or for each of the districts into which its system may be divided.
    (a) For service rendered to customers whose principal consumption shall be for lighting and/or residential purposes, the voltage at the point of delivery shall not exceed 5% above or below the standard voltage adopted.
    (b) For service rendered principally for industrial or power purposes, excluding residential purposes, the voltage at the point of delivery shall not exceed 7 1/2% above or below the standard voltage adopted.
    (c) Sudden changes in voltage that exceed 5% of the standard voltage and occur more frequently than two times per hour, or changes of 2 1/2% that occur more frequently than once per minute shall be limited to magnitudes and frequency of occurrence compatible with the customer’s requirements.
    (d) The limitations in paragraphs (a), (b) and (c) may be modified for cases in which the customer specifically agrees to accept service not meeting the specified limits.
    (2) Where the utility’s facilities are reasonably adequate and of sufficient capacity to carry the actual loads normally imposed, the utility may require that the equipment on the customer’s premises shall be such that the starting and operating characteristics will not cause an instantaneous voltage drop of more than 4% of the standard voltage, measured at the point of delivery, or cause objectionable flicker to other customers’ service.
    (3) Variations in voltage in excess of the limits specified above caused by service interruptions, action of the elements, temporary separation of parts of the system, infrequent and unavoidable fluctuations not exceeding five (5) minutes duration, operation of the customers’ equipment at low power factor, unbalanced loading, or other causes beyond the control of the utility shall not be considered a violation of this rule.
Rulemaking Authority Florida Statutes § 366.05(1). Law Implemented 366.03, 366.04(2)(c), (5) FS. History-New 7-29-69, Formerly 25-6.46, Amended 2-25-93.