ELECTRICALLY DRIVEN IRRIGATION MACHINES 70-693

(1) The full-load rating of any motor in the circuit shall not exceed 6 amperes. (2) Each motor in the circuit shall have individual overload protection in accordance with Section 430-32. (3) Taps to individual motors shall not be smaller than No. 14 copper and not more than 25 feet (7.62 m) in length. (b) Individual Protection Not Required. Individual branch-circuit shortcircuit protection for motors and motor controllers shall not be required where the requirements of Section 675-10(a) are met. 675-11. Collector Rings. (a) Transmitting Current for Power Purposes. Collector rings shall have a current rating not less than 125 percent of the full-load current of the largest device served plus the full-load current of all other devices served, or as determined from Section 675-7(a) or 675-22(a). (b) Control and Signal Purposes. Collector rings for control and signal purposes shall have a current rating not less than 125 percent of the fullload current of the largest device served plus the full-load current of all other devices served. (c) Grounding. The collector ring used for grounding shall have a current rating of not less than that sized in accordance with Section 675-11(a). (d) Protection. Collector rings shall be protected from the expected environment and from accidental contact by means of a suitable enclosure. 675-12. Grounding. The following equipment shall be grounded: (1) All electrical equipment on the irrigation machine; (2) all electrical equipment associated with the irrigation machine; (3) metal junction boxes and enclosures; and (4) control panels or control equipment that supply or control electrical equipment to the irrigation machine. Exception: Grounding shall not be required on machines where all of the following provisions are met: a. The machine is electrically controlled but not electrically driven. b. The control voltage is 30 volts or less. c. The control or signal circuits are current-limited as specified in