MOTION PICTURE PROJECTORS

70-581 F. Substations 530-61. Substations. Wiring and equipment of over 600 volts, nominal, shall comply with Article 710. 530-62. Low-Voltage Switchboards. On 600 volts, nominal, or less, switchboards shall comply with Article 384. 530-63. Overcurrent Protection of DC Generators. Three-wire dc generators shall have protection consisting of overcurrent devices having an ampere rating or setting in accordance with the generator ampere rating. Single-pole or double-pole overcurrent devices shall be permitted, and no pole or overcurrent coil shall be required in the neutral lead (whether it is grounded or ungrounded). 530-64. Working Space and Guarding. Working space and guarding in permanent fixed substations shall comply with Sections 110-16 and 110-17. (FPN): For guarding of live parts on motors and generators, see Sections 430-11 and 430-14. Exception: Switchboards of not over 250 volts dc between conductors, where located in substations or switchboard rooms accessible to qualified persons only, shall not be required to be dead-front. 530-65. Portable Substations. Wiring and equipment in portable substations shall conform to the sections applying to installations in permanently fixed substations, but, due to the limited space available, the working spaces shall be permitted to be reduced, provided that the equipment shall be so arranged that the operator can work safely and so that other persons in the vicinity cannot accidentally come into contact with current-carrying parts or bring conducting objects into contact with them while they are energized. 530-66. Grounding at Substations. Noncurrent-carrying metal parts shall be grounded in accordance with Article 250. Exception: Frames of dc circuit breakers installed on switchboards.