PIPE ORGANS

650-1. Scope. This article covers those electrical circuits and parts of electrically operated pipe organs that are employed for the control of the sounding apparatus and keyboards. 650-2. Other Articles. Electronic organs shall comply with the appropriate provisions of Article 640. 650-3. Source of Energy. The source of power shall be a transformertype rectifier, the dc potential of which shall not exceed 30 volts dc. 650-4. Grounding. The rectifier shall be grounded according to the provisions in Article 250. 650-5. Conductors. Conductors shall comply with (a) through (d) below: (a) Size. Not less than No. 28 for electronic signal circuits and not less than No. 26 for electromagnetic valve supply and the like. A main common-return conductor in the electromagnetic supply shall not be less than No. 14. (b) Insulation. Conductors shall have thermoplastic or thermosetting insulation. (c) Conductors to Be Cabled. Except for the common-return conductor and conductors inside the organ proper, the organ sections and the organ console conductors shall be cabled. The common-return conductors shall be permitted under an additional covering enclosing both cable and return