§ 50.25  POWER INSTALLATIONS.
   (A)   Single phase motors up to but not exceeding three horsepower may be connected to a lighting service under the following conditions.
      (1)   Single phase motors not in excess of one-third horsepower may be wound for 115 or 230 volts and may be operated from a lighting circuit.
      (2)   Single phase motors one-half horsepower to three horsepower, inclusive, must be wound for 230 volts, be connected across the 230 volt legs of the three-wire lighting service, and be operated from a circuit separate from any lighting.
   (B)   Energy for lighting may be taken from a power service within the limitations of the applicable rate, but from a separate branch circuit.
   (C)   The utility will supply single phase or polyphase service in accordance with the following general provisions.
      (1)   Installations aggregating three horsepower or less shall use single phase service unless polyphase service of the desired voltage is adjacent to the customer's premises.
      (2)   Installations aggregating more than three horsepower and not more than 7-1/2 horsepower may use either polyphase service or single phase service, whichever is adjacent to the customer's premises, at the desired voltage.
      (3)   Installations aggregating more than 7-1/2 horsepower shall use polyphase service.
   (D)   The utility may require the use of such starting or current limiting equipment as may, in its opinion, be necessary for any motor or apparatus to prevent undue disturbance, or voltage fluctuation on its lines.
('75 Code, § 6.11)