COMPUTER/DATA PROCESSING EQUIPMENT 70-673

Exception No. 1: Where the interconnecting cables are enclosed in conduit or raceway. Exception No. 2: Interconnecting cables listed with equipment manufactured prior to July 1, 1994 shall be permitted to be reinstalled with that equipment. Exception No. 3: Other cable type designations that satisfy the above requirement are Type TC (Article 340); Types CL2, CL3, and PLTC (Article 725); Type FPL (Article 760); Types OFC and OFN (Article 770); Types CM and MP (Article 800); Type CATV (Article 820). These designations shall be permitted to have an additional letter P or R. (FPN): One method of defining fire resistance is by establishing that the cables do not spread fire to the top of the tray in the "Vertical Tray Flame Test" referenced in the Standard for Electrical Wires, Cables, and Flexible Cords, ANSI/UL 1581-1985. Another method of defining fire resistance is for the damage (char length) not to exceed 4 feet 11 inches (1.5 m) when performing the CSA "Vertical Flame Test - Cables in Cable Trays, as described in Test Methods for Electrical Wires and Cables, CSA C22.2 No. 0.3-M-1985. (e) Securing in Place. Power cables, communications cables, connecting cables, interconnecting cables, and associated boxes, connectors, plugs, and receptacles that are listed as part of, or for, electronic computer/ data processing equipment shall not be required to be secured in place. 645-6. Cables not in Computer Room. Cables extending beyond the computer room shall be subject to the applicable requirements of this Code. (FPN): For signaling circuits, refer to Article 725; for fiber optic circuits, refer to Article 770; and for communication circuits, refer to Article 800. For fire protective signaling systems, refer to Article 760. 645-7. Penetrations. Penetrations of the fire resistant room boundary shall be in accordance with Section 300-21. 645-10. Disconnecting Means. A means shall be provided to disconnect power to all electronic equipment in the electronic computer/data processing equipment room. There shall also be a similar means to disconnect the power to all dedicated HVAC systems serving the room and cause all required fire/smoke dampers to close. The control for these disconnecting I means shall be grouped and identified and shall be readily accessible at the principal exit doors. A single means to control both the electronic equipment and HVAC systems shall be permitted. Exception: Installations qualifying under the provisions of Article 685. 645-11. Uninterruptible Power Supplies (UPS). UPS systems installed within the electronic computer/data processing room, and their supply and output circuits, shall comply with Section 645-10. The disconnecting means shall also disconnect the battery from its load. Exception No. 1: Installations qualifying under the provisions of Article 685. 70-674 NATIONAL ELECTRICAL CODE Exception No. 2: A disconnecting means complying with Section 645-10 shall not be required for power sources capable of supplying 750 voltamperes or less derived from UPS equipment or from battery circuits integral to electronic equipment, provided all other requirements of Section 645-11 are met. 645-15. Grounding. All exposed noncurrent-carrying metal parts of an electronic computer/data processing system shall be grounded in accordance with Article 250 or shall be double-insulated. Power systems derived within listed electronic computer/data processing equipment that supply electronic computer/data processing systems through receptacles or cable assemblies supplied as part of this equipment shall not be considered separately derived for the purpose of applying Section 250-5(d). (FPN No. 1): This listed equipment provides the bonding and grounding requirements in accordance with the intent of Article 250. (FPN No. 2): Where isolated grounding-type receptacles are used, see Section 250-74, Exception No. 4. 645-16. Marking. Each unit of an electronic computer/data processing system supplied by a branch-circuit shall be provided with a manufacturer's nameplate, which shall also include the input power requirements for voltage, frequency, and maximum rated load in amperes.